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Questions related to Hydrodynamic Modeling
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I want to use a hydrodynamic model to simulate the dispersal of plastic along a coastline. This can be done using the 2md generation SLIM model (https://git.immc.ucl.ac.be/slim/slim). However, it is Python based and I was hoping anyone might know of an R based alternative? Or will I have to bite the bullet and learn Python?
Any recommendation for open-source and free alternatives would be much appreciated.
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Adnan Majeed thank you, this is interesting, but I was hoping to find an alternative in R. This model is Python as well
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I am trying to learn how to use EFDC+ 8.5 to model an estuary, it has to be efdc+ because the hydrodynamic model is in EFDC+. I do not have access to the EE GUI. I haven't been successful in compiling the source code to run yet and was wondering if anyone out there has successfully run EFDC+ using visual explorer.
If so, what resources did you use to learn how to so it?
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It's been a while, but I ran a bunch of models with EFDC (see link below): rivers, bays, estuaries, etc. I have several EFDC models on my keychain that will run right now (executable + inputs). It's a great tool. I have the original FORTRAN (several versions). I worked on the code with John Hamrick back in the day. The FORTRAN is no sweat to compile. I think I translated the entire code into C at some point. I have some pre- and post-processing tools too. I will dig through my off-line storage. http://dudleybenton.altervista.org/projects/Diffusers/90DegreeShells.gif
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I'm finding a 3D hydrodynamic model that considers the processes of water & sediment quality and sediment transport at the same time.
Delft3d seems to be a good one, as Delft3d-WAQ couples the deposition of organic matters and sediment transport and wave can be computed as well.
SCHISM seems to be another good model system as it contains all needed module, however, I'm not sure if it can work as Delft3d-WAQ.
Therefore, I want to ask:
1. Is SCHISM okay for the above requirements (considering the processes of water & sediment and sediment transport at the same time)?
2. Is there any other models that meet these requirements?
Your help will be the most grateful.
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FVCOM is a great option. I recently used it to model wave-current-sediment-bacteria interactions. Please See my paper for more details:
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Currently I'm working on a project related surface ship simulation. We need to simulate a plenty of ship types. I modeled propeller, rudder etc. But hydrodynamic forces are modeled as hyrodynamic derivatives (hyrodynamic coefficients, maneuvering coefficients ). For some ships, we generate our hyrodynamics data, but as I said, we need lot more. We dont want to spend time on CFD. We need direct data of Hydrodynamic of some ships. Is there such a company/institute/university/organization etc.? Any suggestion?
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Follow the references [14, 35, 36] mentioned in the following manuscript for coefficients of DTMB 5415, PCC, and VLCC ships
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The question is about hydrodynamics and coastal water quality modeling.
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I forgot I had this overlay which shows the difference between rectangular and curvilinear grids better.
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Hi everyone, I've been running this Sdevice code to obtain a 14 nm finFET thermal simulation, but the results doesn't match with the expected. Do you have any suggestions or tips that I could use to run this simulation? Thanks in advance.
#==================================================
# dessis.tpl
#
# for use with run_dessis.tel
#==================================================
#setdep @node|iClassDDmodToxWf@
#setdep @node|xreflect@
#define _Hmodel_ Hydrodynamic(eTemperature)
#define _EQUATIONSET_ Poisson Electron Hole eTemperature Temperature
#define _QC_ eQuantumPotential
File
{
Grid= "n@node|xreflect@_reflectx_msh.tdr"
Piezo= "n@node|xreflect@_reflectx_msh.tdr"
Parameter="@parameter@"
Current= "@plot@"
Save= "@save@"
Plot= "@tdrdat@"
Output= "@log@"
}
electrode {
#if "@Type@" == "nMOS"
{ name=gate voltage=0.7 }
#else
{ name=gate voltage=-0.6 }
#endif
{ name=substrate voltage=0}
{ name=source voltage=0 Resistor=40 }
{ name=drain voltage=0 Resistor=40}
}
Thermode{
{ Name="substrate" Temperature=300 SurfaceResistance=1e-4 }
}
Physics{
_Hmodel_
_QC_
RecGenHeat
AnalyticTEP
ThermalConductivity()
Temperature=300
EffectiveIntrinsicDensity( BandGapNarrowing(OldSlotboom) )
Mobility(
DopingDep
eHighFieldsaturation( CarrierTempDrive )
Enormal(Lombardi)
)
Recombination(
SRH( DopingDep TempDependence )
)
}
physics(Material=SiliconGermanium){
Piezo( Model( DeformationPotential( minimum ekp hkp )
DOS (eMass hMass)
#if "@Type@" == "nMOS"
mobility(esaturationfactor=0.0 efactor(kanda sfactor=MCmob(Type=0)))
#else
mobility(hsaturationfactor=0.0 hfactor(kanda sfactor=MCmob(Type=1)))
#endif
)
Stress=(@Sxx_Pa@,@Syy_Pa@,@Szz_Pa@,0.0,0.0,0.0)
)
mobility (
highfieldsaturation
Enormal(Lombardi(AutoOrientation) )
PhuMob
)
EffectiveIntrinsicDensity ( Slotboom NoFermi )
Recombination ( SRH(DopingDep) Auger )
}
Math {
-CheckUndefinedModels
Method=blocked
Submethod=pardiso
Digits=6
Extrapolate
Derivatives
Iterations=50
Notdamped=50
NumberOfThreads= 8
-ExitOnUnknownParameterRegion
ExitOnFailure
}
Plot{
*--Density and Currents, etc
eDensity hDensity
TotalCurrent/Vector eCurrent/Vector hCurrent/Vector
eMobility hMobility
eVelocity hVelocity
eQuasiFermi hQuasiFermi
*--Temperature
eTemperature Temperature *
*--Fields and charges
ElectricField/Vector Potential SpaceCharge
*--Doping Profiles
Doping DonorConcentration AcceptorConcentration
*--Generation/Recombination
SRH Band2Band * Auger
AvalancheGeneration eAvalancheGeneration hAvalancheGeneration
*--Driving forces
eGradQuasiFermi/Vector hGradQuasiFermi/Vector
eEparallel hEparallel eENormal hENormal
*--Band structure/Composition
BandGap
BandGapNarrowing
Affinity
ConductionBand ValenceBand
eQuantumPotential
}
#if "@Type@" == "nMOS"
Solve {
*- Build-up of initial solution:
NewCurrentPrefix="init_"
Coupled(Iterations=100){ Poisson _QC_ }
Coupled{ _EQUATIONSET_ _QC_ }
*- Bias drain to target bias
Quasistationary(
InitialStep=0.01 MinStep=1e-5 MaxStep=1
Goal{ Name="drain" Voltage= 0.7 }
) { Coupled { _EQUATIONSET_ _QC_ } }
}
#else
Solve {
*- Build-up of initial solution:
NewCurrentPrefix="init_"
Coupled(Iterations=100){ Poisson _QC_ }
Coupled{ _EQUATIONSET_ _QC_ }
*- Bias drain to target bias
Quasistationary(
InitialStep=0.01 MinStep=1e-5 MaxStep=1
Goal{ Name="gate" Voltage= -0.7 }
) { Coupled { _EQUATIONSET_ _QC_ } }
}
#endif
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good luck
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Discussion of the state of art on the application of the Ertel's potential vorticity theorem in atmospheric physics & physical oceanography.
Prof. H. Ertel generalized Rossby's work proposal of 1939. Prof. Rossby firstly proposed that instead of the full three-dimensional vorticity vector, the local vertical component of the absolute vorticity is the most important component for large-scale atmospheric flow.
Via an independent paper published in 1942, Prof. Ertel identifying a conserved quantity following the motion of an air parcel proved that a certain quantity called the Ertel potential vorticity is also conserved for an idealized continuous fluid.
Several links to check on the topic powered by ResearchGate:
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A very complete review on Ertel potential vorticity theorem, thank you for suggesting its reading, Prof. Aref Wazwaz .
Best Regards.
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I am very new in hydrodynamic modeling. Recently, I have done a simulation in SMS-SRH 2D. Now, I want to perform calibration and validation of my model. But, I have no basic on calibration and validation. Can anyone give me some documents or tutorial or guidelines on calibration and validation of numerical model which will, not only build my basic but also make me able to perform on my existing simulation?
Some specific questions:
1) What are the parameters need to be used for fine tuning of model during calibration?
2) If I have limited observed data, will model give satisfactory result?
3) During validation, shall I use different cross section of another time period for my model domain?
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Hi, you are talking of hydrodynamic mathematical 2D model. For calibration and / or verification studies, you would require a few prototype hydraulic observations, like velocities with direction, depths of flow, water levels at different locations. Corresponding discharges are of critical importance. If gauge discharge curves are available within the reach reproduced in the model, then it is of immense value.
You will require discharge hydrograph for control of discharge at the upstream end and a gauge discharge at the downstream end of the model for water level control.
As you are at the "Verification stage", it is assumed that these are already available and used for the studies.
Initially, you are required to run the model with the specified discharge values at the upstream end and water level control curve at the downstream end.
The first stage is to reproduce the average water surface slopes for the different discharge stages. For calibration of the same, the Mannings' value on n needs to be corrected / adjusted.
After getting satisfactory results, for the specific discharges (Depending up on the available prototype data) you may have to look at the flow conditions (Velocities with direction, depth of flow, etc) for the specific discharges.
Most of these verification studies are problem-dependent. Each and every parameter observed at the site may or may not be correctly reproduced all the time. A description of the modeller is many times required.
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Hello I want to model the Upwelling phenomenon in the northern part of the Oman Sea Which model or models do you think I should use?
also
I want a model that is not yet complete and can be upgraded
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I think, ''Coupled Atmosphere-ocean Mesoscale Model'' would be a batter option in your case. Have a look at the attached article.
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I want to use standard sandpapers of different grit sizes to impart flow resistance to a surface. I am wondering how to convert the roughness of sandpaper to an equivalent sand-grain roughness. Is there any established correlation between grit size and equivalent sand-grain roughness?
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Hello everyone. I have a question about microfluidic-based methods. In this article, "Microflidic-Based Approaches in Targeted Cell/ParticleSeparation Based on Physical Properties: Fundamentalsand Applications", It has been mentioned that flow rate in methods with external force fields such as electric field, optical field,etc. are relatively low compared to fluid dynamics-based microfulidic separation methods such as Pinched Flow Fractionation, Deterministic Lateral Displacement, Inertial Method, etc.
My question is that why the flow rate in methods with externally applied forces is relatively low compared to fluid dynamics-based microfulidic separation methods?
Thank you for your time.
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External forces are usually proportional to the volume of the cell (or particle) and thus very small. In order to effectively separate cells you want them to be displaced by that force meaningfully. So the tiny force must be applied to the cells for enough long time. This means fluid velocity must be small. On the other hand in fluid dynamics-based methods separation is done by cells following local fluid patterns. These fluid patterns are stronger at higher flow rates, so separation is more effective with higher velocities.
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I just wish to know if there is any reference for treatment of islands/large sand patches/sand bars in rivers of width greater than 1 KM in 1D hydrodynamic models. Such kind of studies can be easily done in 2D hydrodynamic models however, but I am interested to know how such situations have been treated in 1D hydrodynamic models in past literature.
One way which I can think is to imagine a reduced cross section of the river by combining the width of river's distributaries on either side of the island and also taking its cross section as an average of the cross section of rivers on either side of the island. However, this could introduce several uncertainities.
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Karan,
If you consider two cross sections on sides of the island as your computational cross section of the 1D model, you still need to change the roughness of your 1D model to account for the bar/island in the middle (you loss momentum there, compared to your numerical model).
Basically, go back to fundamentals of 3 Momentum and Mass Balance solution for flow of water:
1- If you want to capture everything you need a 3D CFD model of free surface with "good" turbulence model (like DES, LES, DNS....)
2- One level simpler is 3D CFD model (3 momentum and one mass balance) with a lid on top (this only works for cases without wave in surface and low Froud numbers). You loss some measures of turbulence
3- Still one level simpler is 3D hydrostatic model (2D+1D) you have stratifications but you loss many 3D "fast effects".
4- One level simpler is 2D (depth averaged N-S equation which is known as 2D Saint Venant or Shallow-water-wave equation) here you loss all effects in vertical direction and secondary flows (but you still capture super elevation and curve effects)
5- One level simpler is (depth and width averaged N-S equation which is 1D Saint Venant Equation) Here you loss every variation in depth or width. In other words for all of the cross section you have one value of velocity, one value of roughness and one value of depth.
6- One level simpler is only see mass balance in compartments (Muskingum Cunge method) you only see mass balance and ignore momentum balance in 1D.
You better well understand the above hierarchy and the limitation of each, therefore you can understand which phenomenon is/ is not capturable with what model?
You cannot capture an island or bridge pier with 1D Saint Venant solver, you can "Change" that model to SOMEHOW mimic the behavior of that partially. And by partially you should see what is the variable of interest in your study.
Hope it helps,
Kaveh
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I have run a hydrological & hydrodynamic model of a river system for 72 hours time lag using MIKE 11 software. When I evaluate the performance of the model for 24, 48 & 72 hours, the R square value is coming 0.78, 0.38 & 0.39 and Nash Sutcliffe Coefficient (NSC) value 0.73, (-) 0.49 & (-) 0.79. How we can explain the negative value of NSC?
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A negative NSE means with R2 fairly above zero means that your model has some relevance with reality in terms of the variation, but fails to reproduce the mean. You may try to change the model parameters focusing on preservation of the mean.
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Dear colleagues! In the laser powder-bed fusion (LPBF) process, the vapor pressure plays a significant effect on the spatter and keyhole pores formation. Unfortunately, there are few publications that show the measured or simulated vapor pressure. So what is the general magnitude of the vapor pressure in the LPBF process?
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Ratul Biswas Many thanks, Ratul. This is a very time-efficient approach, appreciated. I am also looking for some numerical/experimental results, and got one on this paper with a 2D cross-section over the melt pool, .
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In metals, the outermost conduction electrons (electron plasma) interact with incident photons and according to the classical Drude model, they may resonate and build up longitudinal plasmonic waves either in bulk or surface depending on photons' energy. Similarly, high doped semiconductors and in some cases an intrinsic semiconductor like InSb can support these collective oscillations. But, based on our knowledge, we have both electrons' and holes' plasma in semiconductors which can interact with external perturbations like photons. Hence, why we consider only the electrons share in the plasmonic response of semiconductors?
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This is an interesting question. As answer, you can compare a metal with one of these semiconductors. For plasmonic modeling, metal is considered with two parts as positive ionic substrate and conductive free electrons; where the ionic substrate is ignored in modeling. Also, in semiconductor, the free electrons and positive ionic substrate made by atoms including holes can be considered as the two parts; similarly in here, holes as ionic substrate should be ignored.
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I am trying to run a coupled model (HD and SW MIKE 21), for a one year period (8760 time steps; 3600 time step interval). However, after approx 200 time steps there is an Abnormal Run error, 'Blow-Up wave height too large'. What are some reasons that would cause this, and some solutions?
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Ariel Mohan Aesthetics in cities are not merely a matter of taste, but something that is linked to culture and what is most noble in a community. It reflects a world of meaning about that space and the people who occupy it, in addition to maintaining order and a sense of transcendence. Urban aesthetics is a way to exalt this world of meaning and express the ideals and values of a people. It is not a question of preserving the traditional because it is old, but of preserving the past due to its importance and beauty. Beauty is a spiritual good and, as a spiritual good, it is part of who we are. I recommend reading the attached text.
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There is a categorization for Hydrological Models which divides them into three groups: Empirical models, Physical Models and Conceptual Models.
The question is: Where exactly "Hydrodynamic Models" stand within this categorization?
Are those three types related to rainfall-runoff models and Hydrodynamic models are within a different group?
Or Hydrodynamic Models can be a combination of those three types (i.e. a combination of Empirical and Conceptual Models)?
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A hydrodynamic model uses a numerical approximation (e.g. finite element or finite difference methods) to solve a PDE (e.g. shallow water wave equation, Saint-Venant equations). As such, these are physically-based models (or physics-based models if you prefer). You might use the output of an empirical or conceptual model to give the flows at the upper part of a reach being studied (i.e. set a boundary condition for solving the PDE), but a hydrodynamic model is a physically-based model.
Note that I have used "physically-based model" rather than "physical model" - a "physical model" could refer a model built out of concrete, plaster etc. for running simulations in a laboratory (i.e. not in a computer). For example, a scaled model of a floodplain used to study flood characteristics by actually running water over it.
It could be argued that a hydrodynamic model is a "physics-based" model rather than a "physically-based" model.
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"Error No 16 : In the Boundary file a boundary is defined in BRAHMAPUTRA : 66.600 meter. This location is not specified as an open boundary in the model setup.".What might be the error and in which parameter?
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Good luck
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Does anyone could give information (web site link) about some free softwares for coastal hydrodynamic modeling?
Thank you
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Thanks for Ismail Mondal for a coastal software link , itsvery useful.
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I am interested in hydrodynamic modelling, more specifically, I want to model riverine and coastal processes (i.e., discharge and surge/tide) to assess compound flooding effects in estuarine environments. I am relatively new to MIKE. Can MIKE handle this? If so, can anyone suggest related literature?
Thanks in advance
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Mike21 is a good choice for your interest, we used it in the simulation of Tide and tidal currents estuarine environment.
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We want to model hydrodynamics and currents in any sea and shallow water region. And also, we want to model rip currents and storm surges in shallow water.
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I suggest SWAN+ADCIRC for storm surges
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I have run the model so many times with different spectral values. I have checked whether my projection is correct. Every single time the model shows output as a mirror image of the scatter dataset.
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Khalid Amarouche My problem has been solved. This error occurred as I was using transient bathymetry for the model control whereas my model was non-transient. Thank you, anyway.
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I want to know if Ansys Fluent is an appropriate tool for modeling river bed sediment transport which is a frictional particulate flow regime rather than a collisional regime such as fluidized bed. Fluent has a DDPM-DEM model that can be used, however, I couldn't find any studies that have been used Fluent for this purpose. Thanks
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There are different tools apart from ANSYS Fluent for DDPM-DEM modelling like ANSYS CFX and ABAQUS, which might be easier for user definitions, a bit more precise, as well as couples solid and fluid. However, it all depends on the physics considered. We also carried out DDPM-DEM approach using COMSOL Multiphysics and ANSYS Fluent, and both tools were effective and published.
Based on your system, you may consider using virtual massless particles to see which areas of the bridge are most affected by scouring. It is actually pier scouring, which means scouring of the sediment around the pier.
Based on the physics, let me share this: you can use GKT (Granular Kinetic Theory) in ANSYS-Fluent in the previous papers that are suggested to review. Nevertheless, the authors also used GKT in ANSYS-CFX in the following paper of particles transport (slurry mix) (this was related to flow assurance for oil and gas application). ANSYS-Fluent permits to use the three components of the solid viscosity in GKT, i.e., friction, collision and kinetic, while ANSYS-CFX only permits to use collision and kinetic components.
However, as you will see in this paper, ANSYS-CFX does a very good job as well. The authors were able to capture particles segregation due to gravity and distribution with moderate discrepancies with experiments only on region of wall due to the lack of frictional term in viscosity (as per their conclusion in the paper)
They showed that ANSYS-Fluent is better suited than ANSYS-CFX to deal with particle transport using GKT for slurry flows (at least in ANSYS CFX v.13).
These attached files may help you with answering the question and you can check the references on these papers for more info. Different models are available in ANSYS Fluent and CFX to simulate multiphase flows. These are two models that can be used to simulate the dispersion of sand in gas flow:  
Eulerian – Lagrangian approach: The primary phase is the continuous phase (air for example) and the secondary phase is the discrete phase (particles – sand for example).  Conservation equations are solved for the continuous phase and the particle phase is tracked by solving the equations of motion for each particle. The trajectories of particles (sand) are computed in a Lagrangian frame. The particles can exchange heat, mass, and momentum with the continuous gas phase.
Euler-Euler approach:  In Euler-Euler model all phases are treated as continuous. This model can be used for separated flows where both phases can be described as a continuum. The Euler-Euler approach is used to model dispersed flows when the overall motion of particles is of interest rather than tracking individual sand particles (sand bed for example). The dispersed phase equations are averaged in each computational cell to achieve mean fields. This model is valid (describe a dispersed phase as a continuum), when the volume fraction is high. This model is suitable for dense flows (sand bed for example).
See some mathematical description in this one too on mutliphase flow
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As they both follow Reynolds euqation and the same elastic deformation law, is there difference between the numerical model of them?
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If I understand your question and the term "soft EHL" (soft solid materials?) correctly, there will be some differences.
In traditional EHL, solids are made from hard materials. The contact surface is therefore relatively low, the contact pressure is high (1 GPa or more) and the film thickness is very thin (100-200 nm).
The situation is significantly different in soft EHL: large-size contacts, medium pressure, thicker film thickness.
This will necessarily have consequences on how to solve the problem numerically even if the fundamental equations are the same or almost the same. Reasons among others: the effect of pressure on lubricant viscosity, the extension of the deformed solids zone will be very different, which will very likely require a re-examination of the adimensionalisation and numerical resolution strategies,
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I want to do a numerical study of ship propeller. I can make a random 3D propeller model using CAD softwares. But is there any recomended propeller models or detail information of any propeller geometry - blade shapes, angles, dimensions etc?
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AS I know the propeller blades are designed according to the NACA profiles. every cross section pf the blade is a NACA profile. however, the size of the profiles are different.
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I have question about flood water quality when river water over bank. I use PCSWMM (2D) to simulate flood and water quality in urban area. It is working well with flood from junctions (manholes) which I create from 1D model (SWMM).
In order to simulate the flood when river water over bank, outfall boundary is created in 2D. However, 2D only shows result of flood depth at flooded cells. But not the flood water quality for these cells. (I think since 2D only simulate for flood extend, not water quality).
In this case, what should I do if I want to know the flood water quality in the cells flooding by river water over bank?
I have some ideas like: assuming the flood water quality equal to river water quality. Or create more outfalls in 1D that are linked to the junctions close to boundary. But I am not very sure.
I am a beginner with hydrodynamic model, please give me some advice. Your suggestion is very much appreciated. Thanks in advance.
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You cannot assume flood water quality in the 2D domain is exactly equal to main channel, it has to be modeled on its own.
I worked with XPSWMM and XPFlood (basically same solver in different GUI) if your transport solver (means water quality solver) works, it works everywhere, there most be something in the setting or parameters wrong or problematic that you do not get the water quality okay. My suggestion:
Set up a very simple problem , river with 4 cros-section (only one reach) and a levee and a 2D domain next to that, send a simple hydro-graph inside with water quality on and see if it works in the simple problem or not (very small river attached to very small 2D domain, simple slopes, simple roughness, ...) First get this right and if you cannot send that to the software developers. It is almost impossible to debug and narrow down to your problem in a very large problem which has lots of complexity.
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X values in the Muskingum parameter ranges between (0 to 0.5) and it represents wedge storage. K is the time of travel between the inflow and outflow. Is there any possibilities to estimate K without flow data and with the support of other data.
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Just a quick reminder about trade-off between accuracy and simplicity of a flood routing methods:
Muskingum type methods (hydrologic routing) is only solving mass balance, whereas "Dynamic Wave", "Diffusive Wave" and "Kinematic Wave" are solving mass and momentum balance (in full or with simplifications), those methods are called "hydraulic routing". Hydrologic routing is simple and inaccurate, only good for rough estimation, even if you have gauge data for calibration it has its limits. In lack of gauge data you can run "hydraulic routing" methods and then calibrate your Muskingum, however, if you do the effort and building a hydraulic routing method, then why you use Muskingum?
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Coordinates are circular; z, r and θ.
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Be sure from BC.
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My sentaurus simulation of solar cells usually don't converge at the part after the illumination. 
So before the doesn't converge part, the last successful part is the finishing of Raytracing part:
Summary of RayTrace Total Photons and Powers:
Input Escaped StoppedMinInt StoppedDepth AbsorbedBulk
Photons [#/s]: 7.392E+17 7.076E+17 2.989E+03
...
...
And then the next part is:
Starting solve of next problem:
Coupled ( Digits : 5, Max. #iterations : 30,
Solver : blocked decomposition,
#undamped iterations : 100
)
{ Poisson Electron Hole }
===============================
Computing Coupled( 1 poisson-equation(s) , 1 current-contact-equation(s) ,
1 electron-equation(s) , 1 hole-equation(s) )
using Bank/Rose nonlinear solver.
...
...
Finished because...
|RHS| increased to by more than 1e10.
So can someone tell me what is the problem here? I mean which part of the program is having problem and what kink of problem it is?
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Hello,
maybe you could leave out the variables "Electron" and "Hole" from your des.cmd input file, and just solving the Poisson equation? I used it in a simulation and the solution didn't converge because of no current. But i am not expert about it, so don't care too much on my proposal, even if i hope to be useful.
Good work
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In Groundwater flow problems, the flow equations are linearized using different linearization techniques. Is it possible to apply some kind of linearization technique to soute transport model?
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Kaveh Zamani, Thank you sir.I will go through it.
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Is there a method available in HEC-HMS,SWAT or any other tool ?
We have 30m DEM but hte storm water drains are not seen due to corse resolution could anyone tell me a method to fuse the storm water drains into DEM. 
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Hello Vem,
Have you figure out how to solve the problem. Can you share with me.
Thanks
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I have numerous grid-based result from flood-numerical modeling as a float number. I will use it for the next analysis, and I consider to round it to two decimal digits.
Is it necessary to consider some rule to round off a value number of numerical output (floating number) with no error information?
Can it be considered based on the accuracy of measurement in recent gauge development (i.e. discharge gauge in-site observation)?
And how is such practical method in the field of hydrological modeling?
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In this age of computerized detail, it is easy to find numbers presented with little or no thought on level of significance. You May note stream measurement during higher flows, you find water level changes surging, leaves and debris perhaps, sediment and channel shifting perhaps, velocity changing with location and depth in cross section, and usually short duration of gauging measurements as water level changes shift during storm or flood hydrograph. Perhaps only one or two figures are significant, so a discharge measurement of 127,500.00 cfs may be really best reported as 130,000 (rounded) or even 100,000 cfs if figures of significance would be considered and reported. The 127,500 cfs might be calculated from stage discharge relationship or could be from a flood measurement. If one goes into the flood measurement data, one gets an idea of the various sources of potential error as stage is seldom stable. Most high flow measurements are designed by professionals to attempt to be within plus or minus 10%, recognizing at times of vary rapid change in stage, plus or minus 20% or less may be more realistic. So unless you are dealing with very low and stable flows, values reported to two decimal places are more for show, than significance.
However, when adding up all the changes in flow through time series, I don’t see anything wrong with using non-significant numbers or decimal places from stage discharge relationship to estimate water yield or stormflow, then after calculations, do some rounding or dropping off numbers to better reflect significance. For most discharge measurements, there should probably be only one to maybe at best three significant figures.
If you review various sites of stream gauging by USGS, I think you will find instances of variability in discharge numbers reported related to stage, and sometimes differences in reported values at a single stage. If these sites were specifically selected for their ease of access as well as stability of site, one can assume that the variability presented in the results are probably related to measuring flows and the combination of dynamic change during storm hydrographs.
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Hello,
I wanna conduct the research on river water tempeature modeling for impact assessment on aquatic ecology. Such model could be based on data from hydrological and hydrodynamic model. I know there exists many water temperature models or softwares. Is there any one that can be used to simulate river water temperature for a whole watershed at reach scale or cross section scale?
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CE-Qual-W2 or HEC RAS
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hello
I am trying to create a 3d model using feeflow. I have data concerning the soil profile taken from in-situ testing. Does feflow create a 3d model of the subsoil using the input data that I have ?
i.e: does it predict a probable soil profil with variable soil properties or should I define each layer ?
thank you
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FEFLOW is used mainly for simulating the groundwater flow of aquifers, where the layers are constantly saturated. It can simulate variably-saturated flow which exist at soil but it does not account for crop growth, which can significantly affect this kind of flow. There are no tools
HYDRUS (HYDRUS 1-D is free. You can check if it serves your purpose), however, can account all the processes that develop in the vadoze zone (soil zone) and can create 1d, 2d, 3d using in-situ data. There are some tools incorporated into it that can predict certain hydraulic properties, but not spatial destribution of the soil profile itself, about soil given certain parameters but such tools are prone to errors because they are not properly trained for all the soils found in the world.
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I studied the stationary problem of a one-dimensional bipolar hydrodynamic model of semiconductors.
Then I want to consider the SRH term (see page 9 of the following paper) for the above problem.
Do you know the results of the stationary problem of a one-dimensional bipolar hydrodynamic model of semiconductors with "SRH term" and large doping profile?
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Thank you for your answer. The mass of electron and hole is not conserved in this system. For example, when a hole and electron are recombinated, they become neither hole nor electron. Therefore, the mass of electron and hole in the hole system decreases. On the other hand, when an electron goes out of a hole, a electron and a hole generate. Therefore, the mass of electron and hole in the hole system increases. see page 2 and 3. However, j-k is thus conserved.
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Can someone explain what are the key differences in a hydrodynamic model like MIKE 3 FM and using a CFD model? Is it only about the resolution/ accuracy of turbulence and eddy calculations? Or is there more to it? Thank you
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I believe Mike3 has a vertical non-hydrostatic model included in their package although it works on a rectangular mesh grid only, not flexible.
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Hi everyone
I am looking for some studies or books in (metal or coal) pit lakes that have summarized (if possible) the combined effect of oxygen physical entertainment into bottom thermal zones (eg monimolimnion) and the impact of biogeochemical processes (eg methane, ammonia and hydrogen sulfide oxidation).
Most studies seem to assess these two processes separately or by hydrodynamic modelling. While the latter helps, modelling requires continuous validation. I would be interested in (field) studies integrating both mechanisms to asses the oxygen dynamics (i.e oxygen supply vs oxygen demand).
A great example of what I am looking is:
Thanks – hope to get an answer soon
Daniel
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My current research compares the detailed performance of two widely used hydrodynamic models. Our study include more than one thousand simulations by each model to see how the stratification dynamics is influenced by the future climate warming and reservoir management. Could anyone recommend me some journals for submission?
The impact factor should be around 3 to 4. Because my research mainly focused on the water temperature and didn't include other ecological indicators (e.g. nutrients, oxygen and algae), I supposed it may not be appropriate to submit to the enviromental journals (Science of the Total Environment, Journal of Environmental Sciences and so on).
Any suggestions will be highly appreciated! Many thanks!!
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Hi Chenxi,
depending on your focus, you could try some of the climate journals (such as climatic change), or limnology journals such as Limnology and Oceanography. If your paper is quite quantitative, you might consider Water Resources Research.
it would also be a good idea to look at where the papers you cite in your introduction and discussion were published and consider submitting there.
finally, publishing is getting more difficult, if you have the bad luck to have your submission rejected from the first place you send it, try to address some of the reviewer comments and submit it somewhere else.
Martyn
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Hi guys, I am currently building a mathematical model for simulating cable motions underwater. It involved a partial differential equation.
However, I am not really familiar with using Matlab. Is there have any tutorial or examples you can suggest? I will appreciate if you could give any advice.
Thank you for your time.
Ps. It is attached the partial differential equation and related article.
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Keep in mind that there are few cases in which you can calculate exact solutions of initial and boundary value problems. In most cases we are forced to calculate approximate solutions in discrete domains, that is, with a finite number of points and not in the continuous domain, which requires replacing the problem in PDE with a problem expressed through relationships based on finite differences, finite elements, finite volumes and others. You can use Newton Raphson's method to solve this approximate system in the finite set of points. Not the original initial and boundary value problem .
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Dear respondent,
for given configuration of five sphere sand particles in two rows.
mathematically modelling of sand particle(dia =0.5mm) movement in sand bed under hydro dynamic drag force, which resisted by friction between the particles and self weight of the particles. How to find the distance moved?
want to find the energy required to move the particle in rough bed and smooth bed condition.
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I am almost always working on a catchments without river discharge. I am trying to think of a smarter way of calibration the rainfall-runoff (RR) model. Common practice has been to calibrate nearby catchment with data and transfer the parameters. Has anybody tried to use the hydrodynamic model to calibrate the RR model?
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Dear Fredrick :
The hydrodynamic model could be useful. For example, with the hydrodynamic model you can calibrate the stream routing of the reaches defined in the hydrologic model (for example by calibrating the X and K of Muskingum method).
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In ANUGA, a hydrodynamic model. I need to define a boundary line. But How to make a dictionary 'boundary' that stores the edges on the boundary?
There is an inbuilt boundary available for the predefined rectangular domain. But I have to define a boundary line for my real problem domain.
Your answer will help me to progress in my project, Please reply
Also if required refer the pages I mentioned below in the attached manual, hoping helpful to get extra clarity.
Page - 7 To get general idea
Page - 9 How boundary conditions are assigned?
Page - 41 onwards To know meshing
Thank you all
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Hi Ramesh,
Use any GIS package (QGIS) to digitise the boundary as a polygon. This polygon can have many vertices (i.e., as many edges). Copy the vertices (X,Y location coordinates in UTM projection) to excel and save as extent.csv. Now read this file in anuga as
bounding_polygon = anuga.read_polygon('extent.csv') # domain boundary
Do not forget to assign tags to as many edges that are defined in your extent.
See attachment for the sample file.
Hope this helps!
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I have compiled waveDyMFoam successfully (OpenFOAM 2.4.0).
But when I use the solver to simulate a free floating ship model in regular waves (only heave motion allowed), the velocity of the ship increases rapidly, making the running process crashed. 
Has anyone  solved the problem?? 
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Considering ensemble based forecasting of let's say stream flow, which one is better; a forecast with high ensemble spread or  low ensemble spread. Its a bit ambiguous: low ensemble spread could mean that all the ensemble members are agreeing and the forecast could be more close to reality but it could also miss the real value by big amount. On the other hand, high ensemble spread could mean that there is high uncertainty but the real value could be forecast within a the ensemble range. So what is a better forecast, high spread or low spread? 
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Hi Michael,
in addition to the answers already given:
It is often said that the spread of the ensemble members around the ensemble mean should equal the root mean square error of the ensemble mean forecast. However, this is only true if the forecast system and model are all perfectly realistic.  
Another simple requirement for a good forecast system is to ensure that the total variance in the ensemble predictions (ensemble mean variance plus ensemble spread about the mean) matches the observed historical variability.
Best
Adam
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In a plug flow tubular reactor, what is the relation between the peclet number for high and low dispersion, N-CSTR in series, and residence time?
Practically, what Pe values are generally obtained for a tubular reactor or columns when operated in upflow direction?
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I have heard that in Pe<1 the behavior is like a perfect mixed and a Pe>100 the behavior is like the plug flow and between 0 and 100 the behavior is far of  ideal... But, I searched in the Fogler, Bird, Levenspiel and Welty... but none of them say something about...
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Hello,
I am trying to make a simulation with HEC-RAS in 1D/2D. I only have the topographic and bathymetric sections for some of the river reaches. There is a scientific method for estimating the geometry of river sections for the reaches without the geometry based on river section of other reaches of the river?
In my case there is a area that is a estuary, however I don't have also the bathymetric/topographic data for this area. There is any method for estimating this based on SRTM data for example or other information?
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Does anyone know about the accuracy of sediment simulation in HEC-RAS?
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First one question, are you talking about suspended sediment or bed load or both?
For bed load:
In order to evaluate the accuracy of sediment transport results comming from HEC-RAS (and actually for any hydraulic software for engineering software) you need to consider the "hydraulic part" and the "sediment part" separetely.
If you are performing a 2D modelling the main issue is the depth averaged approach followed by 2D modells. Trying to keep it simple and practical, this means that the shear stress is actually an average for the whole grid cell. First approximation.
Usually and in order to estimate the shear stress at the boundary (where it is relevant for bed load transport), the "law of the wall" equation is "fed" with the average shear stress and proper height above the bed to estimate shear stress being applied to the sediment. Second approximation.
The more regular your channel, the better this two approximations will perform.
Now to the bed load transport equations. The first thing one needs to be clear about bed load transport equations is that they represent "transport capacity equations" and this  means, that they actually predict sediment transport under unlimited sediment supply conditions (partly because they were developed under such conditions). Such conditions are only found on sand bed rivers, wich are usually large alluvial rivers. For most of the other rivers, bed load is considered to be "supply limited", this means that the actual ammount of transported sediment maybe less than what the river can transport. Third approximation.
Bed load transport equations have been for the most part empirically developed. There is a large number of publications comparing bed load predictions with bed load measurements and in most cases the accuracy of the equations is rated  between 50 to 200 % the measured values. In most cases differences are attributed to not considering sediment supply conditions. Fourth approximation.
Since, and as far as I know, HEC-RAS performs a continous simulation on a dynamic river bed (changes in river bed configuration after each time step are considered), implicitely accounting for armoring (I do not know about hiding or bed form effects)  then the issues treated above are to some extent dealt with, though not completely.
Summarizing. HEC-RAS will not provide results with a much higher accuracy than the one "intrinsically contained" in these approaches and will likely fall also within the same range 50% - 200%.
One final word of caution regarding parametrization. There are some parameters regarding bed load, like the active layer depth, wich are of a conceptual nature, thus making it difficult to set "the correct value"  other than by trial an error, more or less  like it is done with the Gauckler-Manning-Strickler parameter (or simply Manning coefficient) for the hydraulics. And finally take into account that such modelling approach, whether with HEC-RAS or any other software (MIKE, TELEMAC) is highly parametrized and likely to suffer from overparametrization.
In following answers I will attach some papers that might be usefull.
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Can anyone suggest a software capable of simulating stability of breakwaters? I am actually conducting study on rockmounds as oyster bed. The mounds are also acting like a breakwater and so I want to know what arrangement and shape will result into better stability, good water circulation and manage sediment accumulation.
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thanks ill try if i can learn it.. :)
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I am having a LOT of bother with this and am hoping for some suggestions.
I have had an experiment run in a flume with a pier that has a cylindrical bar attached to the front of it - a little below the surface of water - in order to model the effect of 'debris' (represented by the bar)
I cant think of a sensible way to do this, is it even possible?
please help
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i agree with Hansen
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Hi everyone,
Ansys workbench has its Aqwa module to do hydrodynamic analyses of structures. Mine is an offshore structure with a moonpool and I already determined the RAOs (Response Amplitude Operators) of the structure in different wave conditions. What I need is the RAO of wave elevation (free surface elevation) of water inside the moonpool.
Does anybody in the forum know how to calculate it using Ansys Aqwa?
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If you have the moonpool modelled as an open area, you can calculate the RAO's inside the moonpool like you do for the free surface. If you have done the calculations with an closed moonpool you are stuck. Most likely your moonpool relative motions will not be very good due to resonant waves inside. The best is to use a free surface lid inside the moonpool and dampen the waves somewhat. Model tests should be used for benchmarking and damping factor calibration. Success.
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MIKE21 HD (FM and rectangular grid) can model the tsunami waves. I want to use the flexible mesh. To generate the surface file MIKE Tool Box is required, this tool box is accept dfs2 file only but the MIKE 21 Flexible mesh can export dfsu file. How can I convert this dfsu file to dfs2 file as an input for MIKE Tool Box to generate the surface file. Any suggestion please.
Thanks
Shams
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You need to be careful when using the MIKE 21 HD FM model for tsunamis, in fact DHI recommends using the standard rectangular grid model due to possible numerical dispersion. This means that if for instance you model a tsunami generated in Japan and your resolution is coarse until you get to your area of interest in the USA, then your tsunami will not reach your area, but due to numerical dispersion. You will need a very fine mesh all your model area, so that it is not worth using the FM. BUT, if the seismic event is close to your area of interest, then you can use the FM model. You will need to do some test to see if your FM grid is doing the job.
The MIKE 21 Earthquake toolbox can generate the surface displacement for the initial conditions of your model. Since you are using the FM model, you have a .mesh file, but you can also have a .dfsu file with your bathymetry (you can export it in dfsu in the mesh generator). You can then create a new dfs2 from the dfsu file, and then you can use that dfs2 for the toolbox. Generating the dfs2 from the dfsu is pretty straightforward, but let me know if you run into problems.
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To model river discharges and water levels, a hydrodynamic model is used that divides the river network into reach segments. Inflow boundary conditions are required as inputs to the hydrodynamic model. To determine this inflow boundary conditions, a lumped rainfall-runoff model is used to estimate the catchment discharge at the outlet. The question is how to disaggregate this lumped catchment flow (result of the rainfall-runoff model) into inflow boundary conditions along the river network (hydrodynamic distributed model)? More specifically in low land areas where flow inputs are not well defined by tributaries?
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From what you write I am guessing you are interested in subsurface flow and direct surface runoff into the river channel. In either case, the traditional lumped rainfall-runoff models will not help you and I may go as far to say that there is no chance for you to disagregate the results of such a model (it is like trying to identify concrete bricks from a masive concrete wall).
That being said, you may have to change your modelling strategy. One possibility would be a fully distributed model able to describe both surface and subsurface flow including the so called exfiltration (see for example GEOTOP, TOPMODEL, GSSHA). This would probably be the most direct way.
Another way may be soft coupling or linking of submodells, for example you may model the soil profile next to a river with a groundwater modell, where one part of its boundary conditions are defined by the river channel. In this case you would have to do a stepwise modelling, where results from the groundwater model are then used as inflow/outflow from the river channel, thus defining a new boundary condition for the next groundwater modelling step (this means that the approach is/would be labor intensive).
Finally you have the possibility to do hard coupling of models, but that would require a rather intensiv programming effort. Hope it helps.
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Hello guys.
I'm building a 1D hydrodynamic model in steady flow in HEC-RAS 4.1 software, but my question applies to the theory and not the use of the software.
 
For subcritical regime (Froude Number <1), I must define only boundary conditions downstream and, if supercritical, I define only the amount correct?
But my main question is: if subcritical, the downstream conditions must be the Rating Curve or Known Water Surface ? I see in some literatures claiming to be only the Known W.S, when downstream boundary condition (subcritical regime).
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You may use
1. A velocity/flow boundary at upstream and a pressure/water elevation at down stream;
2. A pressure/water elevation at upstream and a pressure/ water elevation at downstream.
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Dear Colleagues, I am developing an analytical model for computing the internal wave celerity in a linearly density stratified fluid in a circular cross-section channel, i.e. in a bounded domain. The solution for a rectangular cross-section channel is given in Baines, 1997 (see the attached pdf for the complete reference). I have used some results by Yih (1980) referred to a full circle cross section. These results map the circle into a rectangular domain and found a solution in terms of Mathieu functions. The results by Yih did not give the dispersion relation of the waves, but it is straightforward to evaluate such a dispersion relation, at least for the long wave approximation, see the attached pdf. A further step is to consider a half-circle cross section with a lid at the top, since my experiments are in a circular cross-section channel half filled. To tackle the problem, I have used the same transformation used by Yih, but changing the rectangular domain (see after eq.25 in the attached pdf). Then the same expression in terms of Mathieu functions for the full filled circle is recovered and with further computations I obtain the same dispersion relation already obtained for the full circle. This is somehow disturbing me, in the sense that it seems that in the long wave approximation the internal wave celerity assumes the same value for the full circle and for the half circle cross-section channel. I would appreciate your comments on this point. Thanks Sandro
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Dear Mr Mirabi,
thank you for your suggestion. However, I was looking for an analytical solution, similar to that depicted in the script attached to my question. In addition, I am interested primarily in internal waves in a fluid at rest, so no turbulence is involved.
Sincerely
Sandro
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Hello all, 
I have read that the CPU simulation time is not linear function of number of SPH particles, but rather the CPU time increases with the number of SPH particles as NlogN. I tried to find this by carrying out same Simulation but with different number of SPH particles and have plot the graph for the same. Please find the attachment and tell me if it is a valid result. 
Thanks... 
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Sorry i dint get you, can u please add some reference to your answer? I had calculated time taken to reach a particle cycle limit ( ex: 16000 cycles), this cycle was also something when my erosion simulation was over.
Thanks...
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Now i am generating a DSM for Hydrodynamic Modelling so need what is RPC and what is important RPC  for Cartosat-1 data.
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Could you tell me the refinement of  RPCs with data collection  (differential GPS)
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Local running is impossible for 3Di hydrodynamic model. Is it possible for other models such as SOBEK, IBER; HEC-RAS 5.0 and Delft3D-Flow? Thanks in advance.
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...you mean if it possible to run them on a workstation and not just on large cluster?
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I'm performing a simple TCAD simulation in Sentaurus 2D Device. As long as I was using Hydrodynamic transport, Lombardi model and SRH recombination, my simulations were converging. Now, when I added density gradient model, my simulation does not converge because of a large |RHS|. I'm doing 20 iterations, InitialStep=1e-3 Increment=0.01 MinStep=1e-5 MaxStep=0.1 targeted to 0.8V. How can I have a successful convergence?
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Very good! Newton's method parameters, as well as mesh refinement, represent always the key to achieve the convergence!
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Please explain the following attached figure which shows the transverse wave cut at y = -0.1, -0.2, -0.3 respectively.
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Thanks a lot.
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I am working on EHD (electro hydro dymanic) and i understand i have to use UDF in fluent for EHD, but I dont khow what udf is and how to use it for fluent.
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u can fall back on the help files
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Is it possible for me to use 1D2D hydrodynamic model for generating  river reservoir or dam to study the flood impact on studied area before and after built reservoir or dam?
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Various investigators at TVA (Tennessee Valley Authority) have published many articles on this over the years. They have also analyzed networks of dams, as they control a large network. You should also check out the Iowa Institute for Hydraulic Research. Both organizations have been involved in the development of dams around the world, including massive projects in China.
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Hi, we are using the Caughey Thomas model in Sentaurus to simulate the electro-thermal characteristics of a one channel GaN HEMT and we made the simulation succesfully converged with hydro; but we could not see the current drop with high drain voltages in drain current, that is self heating effect. We also tried different approaches like using the both first and second formula in Canali model. However, none of these attemtps were enough to see the current drop at high drain voltages. What other model(s) can be used to see the self heating effects for GaN HEMTs in Sentaurus TCAD?  
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Wich Temperature model did you use ?, in that sense also Which mobility model ?
Do you see any difference in the lattice temperature?
We found out when simulating your voltage source as a transient PWL voltage source while having your thermal simulation active delivers more accurate results
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I am wondering if velocity in formula means average velocity of fluid passing through cavitator, or velocity of fluid within the cavitator, between points with different pressure?
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There are many cavitation numbers depending on the purpose of research. If you want to define the incipient or end of cavitation, or cavitation threshold, or supercavitation, initial cavitation erosion or etc. and want to use data from previous studies, it is important to use the same cavitation number and to read the definition where the pressure difference and the speed is taken. In most cases you have to trust the selected cavitation number. Sometimes based on the experimental data (if published), it can make interesting conclusions or change cavitation number and propose new criteria.
If you're doing research perhaps for ultrasonic cavitator you should know the pressure distribution and choose correct place for measurements of the pressure difference and the velocity.
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Im conducting a hydrodynamic simulation in a highly dynamic lagoon/wetland which have constant changes in coastline structure and vegetation. After comparing with other open source application, the closest to current observation is google earth.
Is it advisable for me to use a digitize coastline of google earth for my simulation for research purpose?
and do i need to do some validification or any correction on the digitized coastline image in order to improve its accuracy. Please state some of the method used.
Thanks a lot in advance.
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I know that the coastline behaves like a fractal, so that the coast  length can increase if we use more detailed maps. Another important issue is bathymetry (especially if you study long waves on ocean surface), and I think that it may be difficult to find maps with too detailed information. So probably GoogleEarth is good enough, and you might not even need the highest resolution is some cases. All depends on the type of hydrodynamics that you study.
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What should accuracy level of efficiency test of hydro-electrical turbine be? 
The question is for both model test and field test. I need this for preparing specifications for those tests. I am asking guarantee for weighted average efficieny value and I want to to be able to determine if this guarantee is fulfilled or not. Of course economy and practicality under the existing level of technology are important.
(the net head is 150m, the flow is 25 cubic m /sec).
Best Regards
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The head and quantum of flow are such that the turbine will run without cavitation and will have more than 90% efficiency and accuracy of testing will be around 95%.
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I modeled the pipeline system in the waterGEMS software. In this model I have a pipeline with length of 50 KM. We need 722 lit/s in this pipeline. At the Kilometer of 10+000 to 15+000 the ground elevation is higher than the HGL. The program alarm the negative pressure in this location but the discharge flow is desirable and equal to 722 lit/s. Is this possible or it is the program errors?
In this distance the maximum ground elevation is 1632 m and the HGL in this point is 1629 m.
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Attention please
All of my last explanations are genuine if you don't have any demand in your pipeline system.
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Im working on a hydrodynamic model simulation in a local and small scale area that requires bathymetry input as part of its model setup. I do not have sufficient equipment and resources to do survey using eco sounder or any other modern techniques.
A method suggested to me is to measure the water depth and its GPS  around my study location could be then be plotted in Arcgis to produce its bathymetry. I would like to know what is the advantage/disadvantage to this method and its accuracy/sensitivity. Please do recommend other method/work/paper that is applicable for my problem as well. Just to inform, i will be taking current speed, salinity and tide(tide gauge) data as well.
Thanks a lot in advance for the recommendation and advice.
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Dear Atteleth Peris, There are several approach/methods for bathymetry data collection varying from simple measurements like pole & GPS, single  or  multibeam survey. The major deciding factors are area which you to be survey, purpose of study, resources available etc.  I would suggest you to use the available secondary data sources  for your initial model setup, which you may get  from   hydrographic charts  or any digital databases like C-MAP or CM/93 etc....   
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Currently I am working on CFD simulations of hydrodynamics of 2 phase bubble column reactor through FLUENT.
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Hello
I think the next step can be related to study of oscillating BCRs.
Best Regards 
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Dear all, I want to model some streamwater quality variables (e.g. DO, TSS) using data driven models.
Which of water quality variables can be extracted using satellite images?
Thanks
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Shima, as far as Remote Sensing is concerned it indeed has applications in Water Quality (WQ). Although it cannot replace ground measurements, the strength of Remote Sensing lies in using it in conjunction with ground monitoring systems and of course due to its spatial coverage unlike taking point measurements with ground instruments. There are a number of satellites and sensors whose wavelength channels are sensitive to, for example, Chlorophyll-a concentrations, temperature, Colored Dissolved Organic Matter (CDOM), turbidity, spectral reflectance and a lot of other variables related to WQ. Some sensors such as SeaWiFS, HICO, ALI, MERIS, MODIS, ASTER, VIIRS, TM, ETM+, OLI have specific applications in this regard. NASA regularly conducts Remote Sensing Training programs for people across the globe. Last year there was a similar training program in Water Quality. It would be a good place to start if you are new to this discipline. Later you can judge how far Remote Sensing can be applicable in modeling, interpolation and prediction studies. Follow the link for directions.
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Since 2 months I am trying to catch alga on agar BG-11 (Stanier i in., 1971) and f/2 (Guillard, 1975) using Viable Microbial Cascade Impactor (Tisch Environmental). And I have collected just one dead diatom.... I do not take samples during windy or rainy weather. In the water I can easily see blooms of phytoplankton. The hydrodynamical model (http://model.ocean.univ.gda.pl) shows the level of phytoplankton on average equal to 60 mg / m3. The sample is collected by the hour. Mushrooms are many, algae zero.
Have you any idea where there is a misteake?
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1. Plankton algae do not grow on agar (you could try to make plates with less agar, e.g. 0,5 % or to work with liquid cultures). 2. Algae do not like your medium (use filtered seawater for medium or other other artificial seawater medium, see also here http://www.uni-goettingen.de/en/list-of-media-and-recipes/186449.html).
You could try to culture some algae from water sample to find out about culture conditions which they need.