Science topic

Hydraulics - Science topic

Explore the latest questions and answers in Hydraulics, and find Hydraulics experts.
Questions related to Hydraulics
  • asked a question related to Hydraulics
Question
6 answers
In anticline structure carbonate Reservoir of areal extension 31x10 km with 24 to26 degrees. no compartments. And no faces alteration (hydraulic continuty exist) multiple Downhole samples, MDT, and well testing samples were taken the bubble point ranging from 2140 psi in one flank to 2746 psi as average.
Relevant answer
Answer
If rock samples from core or cuttings are available, it might be possible to see if the source rock interval is more complex than assumed. Taking samples throughout the interval for geochemical analysis might help. Comparing extracted hydrocarbons to pyrolysis results might be enlightening with regard to fluid prediction.
  • asked a question related to Hydraulics
Question
18 answers
https://www.researchgate.net/project/Ancient-Hydrological-Knowledge-and-Old-Hydraulic-Structures Can we share information about ancient hydrological knowledge, old hydraulic techniques, and ancestral water management methods
Relevant answer
Answer
The Central Bank of Tunisia (BCT) has put into circulation a new banknote of 5 dinars (type 2022) with a dimension of 143 mm x 73 mm, bearing the image of the engineer and left-wing activist and agricultural engineer , Slaheddin Amami (1936-1986); Tunisian agricultural engineer who had initiated the reform of the Tunisian hydrological system. He has made important contributions, in particular to the agricultural problems of arid and semi-arid zones, and more particularly, to the genius of local populations to adapt to them by developing ancestral knowledge on the management of water and soil resources, explaining the foundations of dryland farming in southern Mediterranean countries.
  • asked a question related to Hydraulics
Question
2 answers
A question is if in a "normal soil" - never flooded the water pressure at zero or below.
May the soil water flows into the ceramic cup of a tensiometer?
I guess it is not possible because I do have always a hydraulic head inside the ceramic cup (if its filled of water).
Moreover, also in a situation where, momentaneously, water pressure is lower inside the ceramic cup (e.g after a strong rain in a dry period) than outside, it the pressure will be equilibrated quickly (i.e time response of tensiometer), and the hydraulic conductivity of the ceramic is too reduced to allow some identifiable flow.
Anyway - Maybe Im biased. If you do have any theoretical or practical ideas.
Please let me know.
Relevant answer
Answer
Dear Gaurav. Thank you for your time to my question.
What do the readings mean ? I supposed that in a traditional tensiometer is the result of suction from the soil (if it is not saturated) minus the height of the water column inside the tensiometer. For water to flow back into the tensiometer the soil suction should be replaced by pressure (as we do have a water column inside the tensiometer). I guess the field situation where it will occur is when I have a flooding event with a hydraulic head in the soil (positive tension). As I mentioned in my question... Im trying to learn.
  • asked a question related to Hydraulics
Question
6 answers
Hello! I am setting up an experiment in a hydraulic flume with sediment recirculation. We have collected the sediments to be used from an estuary and are finding the bed preparation methods described commonly in the flume literature may need to be modified to work with these particular sediments. Many flume studies use uniform grain size distributions and the sediments do not contain OM. We have autoclaved and desalinated the sediments and sieved to <2 mm. The remaining distribution consists mainly of coarse to fine sands but with a nonuniform distribution including small but influential fractions of silt/clay. Additionally, the sediments contain ~8% OM. Does anyone have experience working with natural sediments in a flume or suggestions of good papers that describe flume set up with estuarine sediments? Many thanks!
Relevant answer
Answer
One method would be to start your flow and simply meter in the sediment from immediately upstream. The longer you run the more realistic the bed will become. Ideally you would load the bed at the expected average flow rate and then conduct your test at some higher flow, in order to actually see movement. If you load and test at the same flow either the bed will not stabilize during loading or it will not move during testing. An auger feeder should work for sediment loading, it is the standard method for testing the sediment removal performance of stormwater treatment devices.
  • asked a question related to Hydraulics
Question
2 answers
Are there binders with pozzolanic and hydraulic properties?
Relevant answer
Answer
It depends, for example, lime is with pozzolanic and hydraulic properties
  • asked a question related to Hydraulics
Question
3 answers
What kind of hydraulic binders do you know besides cement?
Relevant answer
Answer
There are many binders used in construction which include cement, fly-ash, ground, and/or granulated slag, lime, etc.
  • asked a question related to Hydraulics
Question
2 answers
Hello,
I've successfully simulated the closure of a flapper non-return valve as illustrated.
The inlet velocity increases gradually with a specific acceleration.
The following UDF is used to specify the motion of the flapper:
#include "udf.h"
DEFINE_SDOF_PROPERTIES(flappers_motion, sdof_prop, dt, time, dtime)
{
Six_DOF_Object *sdof_obj = NULL;
sdof_prop[SDOF_MASS] = 2.73e-3; /* flapper's submerged weight */
sdof_prop[SDOF_IXX] = 2161.86e-9; /* around the hinge */
sdof_prop[SDOF_IYY] = 367.96e-9;
sdof_prop[SDOF_IZZ] = 2471.27e-9;
real m= sdof_prop[SDOF_MASS];
real L= 0.024479 ;
sdof_prop[SDOF_LOAD_M_X] = 0 ;
sdof_prop[SDOF_LOAD_M_Y] = 0.0;
sdof_prop[SDOF_LOAD_M_Z] = 0.0;
real th_deg = theta * 180 * 7 / 22 ; /* valve opening angle, in degree */
sdof_obj = Get_SDOF_Object(DT_PU_NAME(dt));
if (NULLP(sdof_obj))
{
/* Allocate_SDOF_Object must be called with the same name as the udf */
sdof_obj = Allocate_SDOF_Object(DT_PU_NAME(dt));
SDOFO_1DOF_R_P(sdof_obj) = TRUE; /*1DOF rotation*/
SDOFO_DIR(sdof_obj)[0] = 1.0;
SDOFO_DIR(sdof_obj)[1] = 0.0;
SDOFO_DIR(sdof_obj)[2] = 0.0;
SDOFO_CENTER_ROT(sdof_obj)[0] = 0.0;
SDOFO_CENTER_ROT(sdof_obj)[1] = 0.0;
SDOFO_CENTER_ROT(sdof_obj)[2] = 0.0;
SDOFO_CONS_P(sdof_obj) = TRUE; /* constrained motion */
if (SDOFO_CONS_P(sdof_obj))
{
SDOFO_LOC(sdof_obj) = 0.0;
SDOFO_MIN(sdof_obj) = -0.0349 ; /* min allowable angle */
SDOFO_MAX(sdof_obj) = 1.0471 ; /* max allowable angle */
SDOFO_INIT(sdof_obj) = SDOFO_LOC(sdof_obj);
SDOFO_LOC_N(sdof_obj) = SDOFO_LOC(sdof_obj);
}
}
}
But now I want to simulate the closure of the flapper, taking into account the friction at the flapper's hinge.
I tried to just assign the friction value to "sdof_prop[SDOF_LOAD_M_X]" ,but the flapper started to move backwards (opening) until the flow increases, which is not correct.
So I want to get the value of the hydrodynamic torque of the flapper, and compare it to the friction with some kind of "if statement" that may look like this:
real static_friction= 50;
real kinetic_friction=40;
real hydraulic_torque =??? ;
If (hydraulic_torque<static_friction)
{
sdof_prop[SDOF_LOAD_M_X]=0
}
else
{
sdof_prop[SDOF_LOAD_M_X]=-1*kinetic_friction;
}
BUT THE PROBLEM IS :
I don't know the udf code that can get the actual value of the hydraulic_torque on the flapper to compare it to the friction value.
Your help is highly appreciated.
Thanks a lot in advance.
Relevant answer
Answer
Ok, I've found how,
In case of someone else has the same issue,
Use the macro :
Compute_force_and_moment
Within the 6dof code
  • asked a question related to Hydraulics
Question
2 answers
Yen, B. C. (1987). Urban Drainage Hydraulics and Hydrology: from art to science. Urban Drainage Hydraulics and Hydrology, 1-24.
Thank you so much if you can share it.
Relevant answer
Answer
@John Machell, thanks for your information.
  • asked a question related to Hydraulics
Question
6 answers
If a hydraulic jump is formed in a rectangular channel/flume , then does the location of the jump depends upon the channel l/flume length or does it depend only upon the upstream and downstream depths of the channel , inlet Froude's no. and bed slope and NOT on the channel length?
Relevant answer
Answer
Subham Pal, the important parameters are explained by other scholars. To study the real length of a hydraulic jump I would consider enough length to ensure the jump is formed not due to phenomena, particularly for free flow. This manuscript would be helpful:
  • asked a question related to Hydraulics
Question
2 answers
I am searching for any software which can do analysis of soil stabilization when different Hydraulic and Non hydraulic binders are added to soil. I want to know the Bearing capacity affected and different failure criteria of soil using software.
Relevant answer
Answer
Thanks you Ramin Vafaei Poursorkhabi For your kind response, i would like to know that it is possible to analyse soil strength parameter with this software
  • asked a question related to Hydraulics
Question
4 answers
I am simulating a hydraulic jump in a rectangular flume that has an inlet and an tailgate at outlet. I need to adjust the tail gate opening to get the desired hydraulic jump. So i simulated the case for few time steps but now I want to drop the tail-gate further to obstruct the flow.
I have duplicated the geometry,mesh and setup , then i changed the dimension of my tail-gate (there by closing the outlet opening below the tail-gate further) . I have initialised the case with the existing .cdat file from the previous simulation. But the console shows me DIVERGENCE immediately after running the calculations.I even updated the mesh and re-cheked the setup Could help me with this?
Relevant answer
Answer
Thank you Ahmed Al-Manea , Kristaq Hazizi and Erfan Rahimi so much. I apologise for such a late reply . All of your answers are valuable towards solving my problem.
Well , I managed to overcome this problem simply by reading the case file and data file in stand alone fluent solver and changing the boundary conditions(tail gate height) each time.
  • asked a question related to Hydraulics
Question
4 answers
I am working with hydraulic permeability of hydrogels. I am not sure at what extend the Darcy law is applicable and at what values of pressure, volume flow rate, the Darcy law becomes invalid. Any related papers or ideas would be helpful.
Relevant answer
Answer
As the flow rate approaches zero or when high rates of flow occur in high hydraulic conductivity material like fractures or karst features, the flow may not be linear and thus, Darcy's law does not appropriately present at these conditions.
  • asked a question related to Hydraulics
Question
4 answers
examples, video, papers, pdf it will be welcome
Relevant answer
Answer
hi Mansouri Anas, my email is manica@iph.ufrgs.br
sorry for the late reply
cheers rafae
  • asked a question related to Hydraulics
Question
6 answers
DEAR
I want to start my theses & want to know the last research and problems & non solve able methods or problems in hydraulic jumps in culverts or pipes
thanks alot
Relevant answer
Answer
Dear Reza,
Much research has been done on the hydraulic jump evolving in different forms of channels. But most of these studies have been done from an experimental point of view, until recently in 2022 when the jump length in a smooth trapezoidal channel was examined from an experimental point of view. However, few studies have been carried out on the theoretical study of hydraulic jump in rough channels. Some experimental studies on this subject have been carried out but really very few on the theoretical level. It is true that when determining the final depth of the hydraulic jump in order to dimension the height of the stilling basin assuming that the walls are smooth, this constitutes security. But from a purely theoretical point of view, almost nothing has been done on the study of the hydraulic jump in practical rough channels such as the rectangular, the triangular, the trapezoidal, etc...and even the compound channels.
I, therefore, advise you to focus your research on the theoretical study of the hydraulic jump in channels of different practical profiles with rough walls.
Regards
  • asked a question related to Hydraulics
Question
3 answers
Hello, I am part of a project where we are investigating the behaviour of a hydraulic filter to assess when it needs replacement. Our aim is to do this using a motor current sensor and a pressure sensor past the filter. Plotting the data clearly shows some linear dependencies between the current and pressure.
Our hypothesis is that this linear behaviour will change over time in some aspects as the filter becomes more clogged with particles. One example that has already been attempted was to look at the data from the past 14 days and save the slope of the linear regression, this was then done over a longer period of time to see the trend. The trend of the slope was then plotted over time to analyse the change in behaviour.
We are looking for other more sofisticated ways of analysing the data from literature. Do you have any suggestions for literature reviews, papers or search terms?
Thank you!
Relevant answer
Answer
Time series analysis could throw some revealing facts ...besides redundant analysis....
  • asked a question related to Hydraulics
Question
4 answers
Could you please tell me if you know available literature data on the quality of urban stormwater sewers, along with the measurement of flow and rainfall over the years? I'm looking for hydraulic and hydrological measurements on the scale of minutes or hours at the most. Need several rainfall events for data-driven approaches. Thank you for any information.
Relevant answer
Answer
you may find some data here:
2-years monitoring of a sewer-outlet in Berlin
  • asked a question related to Hydraulics
Question
3 answers
we need studies about Makhool Dam by hydraulic, geology and hydrology studies
Relevant answer
Answer
Please find the paper, i think it will be helpful for you.
  • asked a question related to Hydraulics
Question
129 answers
Also please name your favorite book of Open Channel Flow/Hydraulics you follow for your research and academic activities.
Relevant answer
Answer
I would recommend the following book:
Chaudhry M. H. (2008). Open-channel flow, 2nd Ed., Springer, Berlin, 523.
  • asked a question related to Hydraulics
Question
3 answers
I draw a hydraulic circuit and I want to control the position of the hydraulic cylinder to move the load and i must use a PID controller with a proportional directional control valve.
Relevant answer
Answer
Adeyemi Adeleke thanks for your answer. could you explain more ?
What values ​​should I set for the transfer function parameters?
does the input of the transfer function is error between the actual position and the desired position?
  • asked a question related to Hydraulics
Question
3 answers
Does anyone help me with how I can interpolate the water level record using elevation as a reference? My study area is very rugged topographically, and I need to consider surface elevation during interpolation of the measured hydraulic heads. I am looking for a technical answer pls.
Relevant answer
Answer
@ Ahmed Moussa, I want to interpolate the groundwater level using a surface elevation (DEM) as collateral information. I am thinking of using kriging with the external drift (KED) interpolation method by using the topographic information as external drift. But, I couldn't get the technical idea of finding the drift value and which software is best suited to do this task.
  • asked a question related to Hydraulics
Question
6 answers
Hello, Im currently in an Engineering module of Fluid Mechanics, and I was hoping if anyone could assist me in the process with these 2 questions while my Professor is absent. I feel my process is correct, but i keep getting answers only close to what the real answer is. I wont be reanswering these questions, so anyone who can properly get through it and arrive at the answer would be appreciated
Q1
'A fluid of density 807 kg/m3 flows through a sudden contraction into to a pipe of diameter 17 mm, with final mean velocity 2.4 m/s.
If the total pressure loss is 401 Pa, calculate the diameter of the vena contracta, in mm to 1 decimal place'
Answer: 14.3 ± 0.05
Q2
'Two sealed tanks, whose total pressures differ by 3,764 Pa, a are connected by a pipe of length 82 m and diameter 22.8 cm. A fluid of density 897 kg/m3 flows through from one tank to the other at a steady rate. Calculate the mass flow rate in SI units, to 3 s.f., when
  • the contraction loss coefficient is 0.5 at the entry to the pipe
  • the friction factor for the pipe = 0.05(1+(20x10^3 / d)
  • the downstream tank can be assumed to be infinte.
Answer: 23.1 ± 0.05 (kg/s)
Thank you
Relevant answer
Answer
Q1:
I assume that you are familiar with the expression for the contraction loss:
Loss in total pressure = P_loss = k * rho * v2^2/2, where k = (1/Cc-1)^2, Cc being the ratio of the cross-sectional areas of the vena contracta and the downstream pipe.
If you haven’t learned this, then you may do a google search on the topic of pressure loss during sudden contraction. For instance, you might watch the YouTube videos:
Now, look at the information given in the problem statement:
P_loss = 401 Pa
rho = 807 kg/m^3, v2 = 2.4 m/s  rho * v2^2/2 = 2324.16 Pa
Using this information with the expression for the pressure loss, you can find:
k = 401/2324.16 = 0.17253545366,
and, therefore,
1/Cc-1 = sqrt(k) = 0.41537387215, i.e., Cc = 1/(1+sqrt(k)) = 0.7065271019
For a circular pipe, the area ratio is proportional to square of the respective diameters. Thus, the diameter at the vena contracta is given by:
Dc = sqrt(Cc) * D2 = 14.2893783087 = 14.3 ± 0.05, when truncated to a single significant digit.
Q2:
I am unable to help you with Q2 due to multiple issues related to the empirical expression for the friction factor:
1. The expression “0.05(1+(20x10^3 / d)” includes the symbol “d” which is not explained in the problem statement.
2. If d happens to refer to the pipe diameter, the units for d will need to be given
3. As you can see, the above expression for the friction factor involves unbalanced parentheses. Therefore, it's not clear whether or not the problem statement is missing any information.
In brief, however, the total head loss between the two tanks equals the sum of the losses due to sudden contraction and expansion, respectively, and the friction loss along the length of the pipe. The first two components can be evaluated along similar lines as Q1 above. Then you can use the correct expression for the friction loss to determine the mass flow through the pipe.
  • asked a question related to Hydraulics
Question
5 answers
I am trying to develop a model for predicting bedload transport in a natural mountain river with shallow flow depths based on field measured data of bedload conc. and related hydraulic, geometrical and sediment parameters.
Relevant answer
Answer
  • asked a question related to Hydraulics
Question
3 answers
Hi all,
I am working on a HVAC project where many components(cooling coils, pumps, etc) needs to be modelled newly(new equations), and in addition new hydraulic connections. And EnergyPlus needs to be used for the overall system level simulation. For that I have to write/include the new equations into EnergyPlus. I have heard that the codes in EnergyPlus are written in C++. Problem is I haven't been able to begin with a good start. Primarily- Where do I go to edit/add new codes? ,and how do I create new Hydraulic connections between components? If you could point me to a direction, that would be hugely beneficial.
Thanks
Regards
Asutosh Boro
PDEng researcher Eindhoven University of Technology
Relevant answer
Answer
I totally agree with my colleagues
good luck
  • asked a question related to Hydraulics
Question
3 answers
This Chain Conveyor is used in harvester machine which will run on hydraulic motor.I have given data as length and width and load it will carry.
Relevant answer
Answer
Thanks Zhenyu Zhao Sir
  • asked a question related to Hydraulics
Question
6 answers
Hi, I'm working on a design project from one of my classes and need to draw the hydraulic profile for a water treatment plant, I have the elevations from a civil 3D surface, where we created a layout of the plant, and I calculated the head loss for each of the structures and head loss of the pipes connecting them, what else do I need to complete the hydraulic profile? I'm planning to draw the prolife in cad once I have all heads, elevations, and other needed information.
Thanks in advance.
Relevant answer
Answer
Dear Rc Cf,
I think you can use different alternative software such as: HEC-2, HEC-RAS, Hydraflow… It also depends on the precision you want to achieve for your design.
  • asked a question related to Hydraulics
Question
3 answers
  • Max (P) = Sum(n*g*p*Q(t)*h(t) for t =1:12
Constraints:
1) The maximum and minimum produced power.
2) The maximum and minimum permissible reservoir height.
3) Hydraulic constraints are defined by the reservoir continuity equation.
4) The maximum and minimum permissible reservoir releases.
5) The maximum and minimum permissible reservoir Storage.
is the number of the production period
Relevant answer
Answer
Dear Mohammed Abdi
I have attached the PSO code which I have used. Incorporate your objective function into this and try.
  • asked a question related to Hydraulics
Question
5 answers
Hi, we are testing the coefficient of permeability of a remoulded clay sample using AS 1289.6.7.3, flexible wall triaxial method. However, after saturation and consolidation perculation stage was done for more than 24 hours. However the flow rate is significantly different from initial to final stage and permeability is changing from 1x 10-7 m/s to 1x 10-9 m/s. I believe this could be due to particle clogging in filter papers. I am confused when it comes to decide the permeabiltity. What would be the most accurate stage for selection of flow rate from this attached flow vs time graph?
Effective cell pressure was 50 kPa and the hydraulic gradient was 15.
Relevant answer
Answer
  • asked a question related to Hydraulics
Question
3 answers
My assessment of Different Hydraulic/Morphology Models I get a lot of questions regarding which model to use for Hydraulics and Morphology. The answer will be depends on the case and the required output. Here is my take on different available Hydraulic and Morphological models (Not in order of preference) Mike 21 GPU Mike 21/3 GPU is the most robust and stable software for your purpose. However it’s not very user friendly and has a steep learning curve. It’s very expensive and the post processing is also a pain. It’s the first choice for commercial use. Delft3D  Delft3D FM has the capability but still there are many bugs that will have to be resolved. Also not having Geo referencing capability based on co- ordinate in the mesh generation process is a limitation of Delft3D. With no GPU capability the run time could be long. TUFLOW GPU TUFLOW GPU is becoming popular and can be used with SMS and QGIS, but there is significant learning curve. FLOW3D FLOW 3D is alternative for physical modeling, and it’s not suitable for large scale modeling. CCHE2D CCHE2D does not have a very wide user base, so documentation and help could be limited. Also the free version has limited mesh size. Aquaveo SMS Aquaveo SMS has a very user friendly interface, so can be learnt very quickly. Pre and post processing is great. Some great tools for riverine modeling with sediment transport. With several modules for waves and sediment transport, but again the capabilities are not well documented due to limited user base for wave modeling. HEC RAS 1D and 2D HEC RAS being is good for basic learning. Suitable for steady state and unsteady state modeling. Though I am not fond of the unsteady state modeling, as previously it had a lot of issues and has a lot of limitations. The 2D module has no sediment transport capability. For the 1D model the sediment transport has plenty of bugs and the output is useless. Not a choice for complex riverine unsteady riverine modeling requiring morphology. Telemac 2d Suitable for Academic purpose mostly with limited documentation and manuals.
Relevant answer
Answer
I did see you mention MODFLOW using groundwater vistas.
  • asked a question related to Hydraulics
Question
6 answers
Can anyone give an idea - how is the hydraulic circuit playing a role in the development of aquaculture / fisheries? How can the knowledge on hydraulic circuits help? Why is it important?
Relevant answer
Answer
Can you be more precise: what hydraulic circuit do you refer to, and what type of development you are referring to?
  • asked a question related to Hydraulics
Question
4 answers
However, HydroSight can be used for the joint estimation of aquifer hydraulic properties and gross recharge from incomplete metered groundwater usage. But point estimates of transmissivity(T) from HydroSight are likely to underestimate the aquifer heterogeneity, and for very heterogeneous aquifers they may be biased. Can it be overcome using MODFLOW with ArcGIS using GMS?
Relevant answer
Answer
I prefer MODFLOW using groundwater vistas.
I did a paper with.
  • asked a question related to Hydraulics
Question
6 answers
Hello everyone.
How are you doing?
Can you tell me some articles, theses that deal with the optimization of water networks (drinking water, wastewater and stormwater) with the Epanet software.
Relevant answer
Answer
Dr. Permalnaïck Fabrice, I think Epanet is for identifying the problem in the hydraulic network. It modifies the schema of the network to resolve the problem. it is not a tool to directly optimise the network but it helps the decision maker to propose a better solution to hydraulic failure.
  • asked a question related to Hydraulics
Question
6 answers
I am simulating a rectangular water channel. To validate my numerical results, I want to present a graph containing the enhancement of Nu for this channel with several Re. Then, I compared this variation with another's study where the hydraulic diameter is not the same, however, both channels are mini-channels.
For example:
pls download the paper given below:
In this paper - Under Section 3.1:
The authors validated their model with Fan et al., Ho et al, and Moraveji et al. However, their hydraulic diameters are not same. How is this comparison valid?
Relevant answer
Answer
To understand how to compare your results with an experiment or literature results, please learn the theory of Dimensional Analysis. According to this theory, a phenomenon is governed by dimensionless numbers. For example, in one case, the Nusselt number is affected by the Reynolds and Prandtl numbers. Therefore, when you compare the Nusselt numbers you get with the Nusselt numbers from the literature, you must compare them to the same Reynolds and Prandtl numbers. For the case you are comparing, you need to equate the definitions of Re, Pr, and Nu between your case and the case in the literature. For example, if the Re and Nu numbers are defined by involving the hydraulic diameter in the literature, then you calculate your results at the same Re and Pr.
Good luck....
  • asked a question related to Hydraulics
Question
12 answers
I am using a SVM (supervised) classifier for internal leakage fault detection and classification of a hydraulic actuator, i am considering 3 stages of fault namely low,medium and high levels of internal leakage the method is as follows
1. first a known level of fault is artificially induced into the system
2. system parameters and signals are obtained
3. the SVM classifier is trained using the obtained results and known fault labels
but since the actuator is in a hydraulic excavator the number of data points the can be obtained is constrained (for example i obtained 40 data of each fault class totaling 120 observations)
Is the use of 120 data points to train the classifier justifiable?
Relevant answer
two points
  • asked a question related to Hydraulics
Question
3 answers
What is the hydraulic retention time HRT and Sludge retention time?
can you give example in nitrification process
thank u
Relevant answer
  • asked a question related to Hydraulics
Question
1 answer
Models MHW-3 and WR-6 Narishige hydraulic micromanipulator for electrophysiology. The control knob turns OK but produces no movements in the manipulator at the the other end of the hydraulic line. None of the parts seem to be stuck. I have contacted Narishige but because they are older than 10 years they don't calibrate anymore. Does anyone know a company that can calibrate them?
Relevant answer
Answer
  • asked a question related to Hydraulics
Question
3 answers
Hello scientific community,
In your point of view, is it possible to include the terms of variation of the geometry of a channel in the analytical expression of the Serre-Green-Naghdi soliton?
Relevant answer
Answer
The geomorphic relationships known as hydraulic geometry In general Hydraulic geometry deals with variation in channel characteristics in relation to variations in discharge. Two sets of variations take place: variations at a particular cross section (at-a-station) and variations along the length of the stream (downstream variations). Characteristics responsive to analysis by hydraulic geometry include width (water-surface width), depth (mean water depth), velocity (mean velocity through the cross section), sediment (usually concentration or transport, or both, of suspended sediment), downstream slope, and channel friction.
  • asked a question related to Hydraulics
Question
1 answer
Darcy’s law and pore-scale hydrodynamics:
As against hydro-static equilibrium, during an oil production, when oil and water keeps moving (hydro-dynamic condition) through the pores in an under-saturated oil reservoir, whether the associated hydraulic forces (and in turn, its effect on the hydraulic head) won’t get influenced by the pore-scale processes such as pore-size and tortuosity ‘also’ – resulting from the (possible) marginal ‘mixing of oil with water’ and a significant ‘mixing of gas with water’?
If so, whether the concept of ‘hydraulic head’ associated with Darcy’s law deserves a special attention – when applying for an under-saturated oil reservoir, where a simple ‘average reservoir pressure’ replaces the Darcy's original ‘hydraulic-head’ concept at the macroscopic-scale?
Relevant answer
Answer
I think it related to the density
  • asked a question related to Hydraulics
Question
12 answers
1) I introduce a new external force without mass, coming from the ground, onto the structure, to help the structure to respond to the earthquake and to receive and deflect seismic loads, outside the structure, into the ground, thus controlling the displacements of the structure which deform it above the breaking point and knock it down. 2) I built a mechanism which is the first mechanism in the world that has the ability from the foundation surface with the help of hydraulic jacks to exert horizontal pressure on the ground towards the slopes of a borehole, along its entire height, and at the same time to exert vertical pressures on the ground surface, before the construction of the project. The result of this technique is to compact the ground from the foundation surface and in all directions, in order to stabilize on the one hand and to obtain a strong anchorage of the mechanism, twice the design intensities. Filling the borehole (after condensing) with concrete offers a deep foundation higher than the width they make today, because it has the ability to receive greater intensities of compression and traction. 3) I am the first to insert the double pre-tension using the same pre-tension tendon. I apply the first pre-tension between the ground surface and the anchoring mechanism, and the second pre-tension between the nodes of the top level and the anchor that preceded the ground. The result is that the construction joins the ground like a sandwich. This mechanism does not differ from the prestressed cantilevers of the bridges which rest on pedestals.
Relevant answer
Answer
Good work
Congratulations and best wishes
  • asked a question related to Hydraulics
Question
11 answers
Dear colleagues,
We are looking for specific (or global) PTF functions (with good performance in sandy soils) to estimate hydraulic properties (field capacity, permanent wilting point, available water)
The "sandy soils" we are studying are from the classes sand, loamy sand, sandy loam.
The predictive parameters we are thinking to use are particle size (coarse sand, fine sand, silt, clay, organic carbon, bulk density, CEC, soil types and maybe others)
If someone has worked with this topic. I thank you in advance for your suggestions.
Regards from Brazil
Wenceslau Teixeira
Embrapa Solos
Relevant answer
Answer
very important topic
  • asked a question related to Hydraulics
Question
1 answer
I'm attempting to carry out some experiments which require me to remove the caudal part of mouse spinal cord (S1-Co2).  I came across some literature which describes hydraulic extraction using a syringe to push the entire spinal cord out.  I have tried a few times but the final part of the spinal cord seems too this to fin into a needle.  I also tried to remove the spinal cord from the column using a spring scissor, but I ended up cutting the tissue. Any advice on how to improve my extractions?
Relevant answer
Answer
Hydraulic extraction will not work this low down in the spinal cord. It must be above L6 in order for that method to work. I would suggest that you use a bone nipper and go from the rostral end. Look at the spinal column as if it were a clock with the dorsal side at midnight and the ventral side at 6 o clock. You want to use the nippers and make a cut at 10 and two, then slowly peel off the bone. You will continue this one vertebrae at a time till you get to the bottom of the spinal canal. You can then begin using a pointed INOX tweezer once the spinal column becomes too narrow. The trick is to gently insert the tip of the instrument while putting pressure against the bone so you care careful not to damage the cord. Then apply pressure to the bone, It breaks away quite easily. You must be patient and a microscope helps one you get down to the sacral portion so you don't damage the cord.
  • asked a question related to Hydraulics
Question
2 answers
I'm currently in studying the design of filter system of hydraulic tank. Which type of filter can provide the best efficiency of filtration, more safer, less losses and not easily damage the pumps in hydraulic system?
Relevant answer
Answer
It depends on the oil volume, temperature, viscosity, actual cleanliness code, and objective cleanliness code, actual water content, and objective water content, line pressure. Which is the application?
  • asked a question related to Hydraulics
Question
9 answers
Is it possible to lower the potentiometric surface in a confined aquifer below the confining layer through sustained pumping ? If it happens, what parameter (specific yield or storage coefficient ?) will control the hydraulic properties of the aquifer once the potentiometric surface falls below the confining layer ?
Relevant answer
Answer
In unconfined aquifer upper surface acts as zone of saturation.In confined aquifer it flows under pressure.I cold not reconcile myself to an answer that aquifer yields more when it attains unconfined condition.How an aquifer flowing under pressure yields less than an aquifer flowing without pressure though specific yield is higher than storativity. It is implied that pressure dropped due to reduction in flow through confined aquifer.
  • asked a question related to Hydraulics
Question
2 answers
I am wondering if EN197 1 2000 specifies any non-portland hydraulic cement and nonhydraulic cement?Or in other words EN197 1 2000 only specifies Hydraulic cement that includes Portland cement and Portland-based blended cement?Thanks
Relevant answer
Answer
Non-hydraulic cement is like lime, gypsum and they do not harden initially when water is added. While hydraulic cement harden with water. So the code talks about the two types.
Section 5.2.1, 5.2.2 of the code talks about hydraulic cement and Section 5.2.3 talks about non-hydraulic cement
  • asked a question related to Hydraulics
Question
1 answer
I have tried Idelchik's Handbook of Hydraulic Resistance 4th Edition (2007 page 300) formulas and across some range the formulas are reported valid for, the law of conservation of energy is violated (expansion loss without kinetic exit loss included) and differs from CFD results, underestimating by order of magnitude of about 137 times (while it agrees in other sub-ranges for which it is reported valid within 3% of CFD results).
I have also tried Ekert et al (1976 pages 30 and 36) on NASA's site: https://ntrs.nasa.gov/api/citations/19770005050/downloads/19770005050.pdf
The results in Eckerts also overestimates by as much as 62% of the CFD results when the diffuser cone angle is 5 degrees whereas it agrees within 7% of the CFD results when the cone angle is 1 degree.
Diffuser Loss formulas which agrees within 5% of CFD results for the range it is reported valid for will be appreciated.
The Friction Loss formulas work perfect but the problem is the accuracy of the expansion loss formulas. I need the formulas to run numerical optimization before generating a geometry for CFD so important I get the analytical/numerical formulas .
Thanks in anticipation of the help
Relevant answer
Answer
You will not find a ready-made formula in the literature, you have to establish it yourself. The following link relates to the circular divergent. You can follow the same process for your problem.
Regards
  • asked a question related to Hydraulics
Question
4 answers
Hello, I am developing my degree work on the coordination of hydraulic and thermal units in an energy network and I was wondering if there is any test network with which I can evaluate or compare the results obtained with my work. Thank you very much in advance
Relevant answer
Answer
see this paper : A Four-Dimensional Model of Hydro Generation for the Short-Term Hydrothermal Dispatch Problem Considering Head and Spillage Effects
  • asked a question related to Hydraulics
Question
4 answers
I have an anaerobic reactor which needs to be fed 20 ml of sludge everyday. (Working volume: 300 ml) for 15 days hydraulic retention time. I'd like to feed it alternate days rather than every day, a blunt calculation says feed 40 ml for every 2 days. I guess this will change my HRT, I'd like to know your thoughts and let me figure out a way to address this.
Relevant answer
Answer
I suggest, try to fed settled residue (centrifuged) of the total volume of the feed sludge and discard the supernatant. This wii help to maintain the HRT without the impact of feed shock.
  • asked a question related to Hydraulics
Question
13 answers
Dear Researchers,
What type of software do you use to create hydraulic and electric diagrams? How do you create figures used in your articles?
Best regards,
Łukasz Stawiński
Relevant answer
Answer
PowerPoint is quite limited. InkScape is a very good alternative especially for generating SVG or eps files.
Hydrosim is probably the best for purely hydraulics diagrams.
Finally you could make your library in Autocad.
  • asked a question related to Hydraulics
Question
1 answer
comparison between air suspension and hydraulic one
Relevant answer
Answer
There are some advantages of air suspension over hydraulic suspension:
1.) weight of suspension assembly is less as compared to hydraulic ones as hydraulic suspension assembly consist of additional spring (coil) which serves to support the system and the oil damper to regulate the response of shocks. On the other hand, Air shocks don't need any spring. It can give advantage of both damping and spring reaction.
2.) The stiffness response of air shock varies with the load or stroke position. So chances of catching resonance becomes virtually impossible.
3.) Also the damping coefficient is much low for air shocks.
4.) If valve is installed on the air shockers, then it allows you to change stiffness and travel according to your requirements.
It's not easy to say which is better. Choice between two highly depends on many factors such as vehicle weight, type of terrain it is being used, type of loads and shocks it will experience and amount of wheel travel you are expecting.
  • asked a question related to Hydraulics
Question
2 answers
The check dams used as torrent control works have some characteristics - in my opinion - which are neither quite those of retention dams (hydraulic structures) nor quite those of retaining walls. So, taking into account their behavior over their period of existence (50 to 100 years), a short period the check dam works as a hydraulic structure subject of hydrostatic/hydrodynamic pressures. Then, after the upstream sector is completely filled with sediments, it works as retaining wall, perodically submited to floods. I put this question because, verifying such a structure using Eurocode 7 I obtain larger dimensions than using the old global factors of safety. And a more than 100 years of experience shows that economically the last approach is better. 
According with the experience and technical regulations in the European countries, are them subject of Eurocode 7 or of some special regulations? 
Relevant answer
Answer
Check dams reduce erosion of the area around the highway. They can be designed also using EC 2 ON CONCRETE STRUCTURES.
  • asked a question related to Hydraulics
Question
3 answers
changing the length of hydraulic jump with d/s and u/s water level. collection between drawdown and hydraulic jump in d/s of cross regulators during open gates
Relevant answer
Answer
Worth following
  • asked a question related to Hydraulics
Question
1 answer
What is the method for making a thick flat chromium strip by powder metallurgical method in a container? Is it possible to use a hydraulic press in the environment to compress it?
Relevant answer
Answer
Following
  • asked a question related to Hydraulics
Question
8 answers
I am working on hydraulic energy storage using pumped-storage turbine energy transfer stations. and I want to calculate friction energy losses using Darcy equation .
Relevant answer
Answer
Linear equation but; If the storage head is variable (i.e. during emptying), then the flow will be "Unsteady", and the losses will be exponentially propotional to "V^2" with a curve trend.
  • asked a question related to Hydraulics
Question
3 answers
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?
Relevant answer
  • asked a question related to Hydraulics
Question
5 answers
Wear and tear in steel/stainless steel pump parts like impeller, sleeves, bowl would cause leakage, reduction in the head height, reduce discharge, increase clearances, etc. How does this wear and tear in such part influence the pump parameters? Case studies, personal experiences, professional opinions are all welcome.
Thanks and best regards,
S.C. Atul
Relevant answer
Answer
Have a look at these articles it outlines some of the most important considerations when designing a pump system and offers tips on looking for specific features.
  • asked a question related to Hydraulics
Question
2 answers
in general hydraulic diameter is 4*area of cross-section / wetted perimeter.
but in louvered fins have interrupted fins, so in this type of fin how to determine equation of hydraulic diameter in terms of design parameter.
Please help me in this.
thanks for this in advance
Relevant answer
Answer
The Hydraulic Diameter Dh of the louvered fin is calculated from :
Dh = 4LAmin/As
Where L, Amin, and As represent flow length or heat transfer matrix depth in the airflow direction, minimum free flow area, and the total area for heat transfer on the airside respectively.
Regards
  • asked a question related to Hydraulics
Question
2 answers
We have a hydraulic system (water collector and distributor) which is newly started, how can we calculate its reliability?
Relevant answer
Answer
William F. Hansen thank you very much!
  • asked a question related to Hydraulics
Question
9 answers
For example ATF (Automatic Transmission Fluid).
I have noticed in my readings that they are only limited to measuring viscosity, but I cannot find studies of its viscoelastic properties.
To my understanding an ATF this working conditions is subjected to different levels of shear rate ans temperature.
Relevant answer
Answer
Hi all.
I did some rheological measurements to determine the viscoelastic properties of a commercial ATF (attachments).
I see that the ATF is Newtonian up to a shear rate 10^3 s-1 (equipment limit), also, the values of the storage modulus are low.
The service conditions of an ATF are much more extreme, shear rate> 10^3 s-1 and the starting temperature can be between -30°C to 20°C and in service between 80°C to 120°C on average.
Is the limitation of measuring equipment the little interest in the viscoelastic properties of ATFs?
  • asked a question related to Hydraulics
Question
1 answer
In heat transfer enhancement techniques, various passive techniques such as the insertion of various types of turbulators/inserts in the heat exchanger are used. How to decide the hydraulic diameter for the case in which turbulator insert is being used for calculating the Reynolds number? For the same flow rate, the Reynolds number would be different for different cases (Tube with turbulators and without turbulators). So, effectively we have two unknowns: one is flow rate and the other is the hydraulic diameter for achieving a given Reynolds number.
So, I need to know how to plot the curve of Nu Vs Re for all cases at a fixed Reynolds number value, and is there any standard formula for calculating hydraulic diameter in case of complex shapes such as louvered strip insert or twisted tape insert?
Relevant answer
Answer
Usually the available in literature correlations are based on the Re at the inlet. The Dh is the inlet hydraulic diameter. Most of these correlations are expressed as ratio of Nu turbolaters / Nu without turbolators or so.
  • asked a question related to Hydraulics
Question
1 answer
I have experience in Operations and Maintenance Department for machines and equipment. I can troubleshoot, work and fix Mechanical, Hydraulic, pneumatic and electrical components.
I would like to do research in this topic and topic of mechanical engineering and machining processes.
What kind of research topics I can choose to apply for in universities or institutions?
Anyone can help and give good suggestions
Thank you
Relevant answer
Answer
My advice to you is
try to find a repeated problem that you face in a machine and find out the main causes behind it. After that, present better solution to terminate this problem in the future. For example, in hydraulic system if the cascade connector always showing leaking, try to study what is the main reason behind the properties of the cascade material causing this leaking to change it with better one.
I hope that is helping
  • asked a question related to Hydraulics
Question
8 answers
On what basis were dams designed in ancient civilizations?
Relevant answer
Answer
This space does not allow us to quote the history of the construction of dams.
The first is the legendary kingdom of Sheba whose splendor of their queen is famous in the Bible at the time of SOLOMON. In this kingdom, dams existed at EDRAA, ADSHMA, and near Marib, the capital. Not far from this city existed by far the most important work, the SUDD AL ARIM dam on the Dhana wadi, built around 750 BC. It consisted of an earth embankment of about 4 m high and 600 m long. It was not built at the narrowest point of the river, to avoid flooding and had on each bank of large drainage works in excellent masonry. Around 500 BC, this dam was raised to 7 m and again to 14 m in the year 325 AD. The successive elevations were probably due to the sedimentation of the reservoir which reduced the available capacity, as well as to the increase in water requirements at the rate of the increase in populations. Profiles successive works were triangles, the upstream and downstream facings being inclined at 45 °. The upstream facing was covered with masonry jointed with mortar. So for over a thousand years,
this work was the basis of agriculture and means of existence in the plain of Marib located in the east. After a first rupture in the 5th century, the dam was probably destroyed around 575.
This event is related in the Quran (Sura 34, Verses 14 and following) in the following terms:
“The inhabitants of Saba had 2 gardens crossed by a stream. We said to them: Enjoy the blessings of heaven. This valley is delicious. Be grateful ”. “They gave up worshiping the Lord. We unleashed the heaped waters of a torrent against them. Their submerged and destroyed gardens produced only bitter fruits, tamarisks and nabs ”
  • asked a question related to Hydraulics
Question
5 answers
Basin lag times can be calculated by the CN Lag Method; which is based on the hydraulic length of the sub-basin, CN value, and basin slope. Some paper says,The CN Lag Method was developed for sub-basins less than 2,000 acres (approximately 8 km2 ). It is such a small area. My question is, is it feasible to calculate basin lag times by CN- method for larger areas? if it is, then up to what extent?
Relevant answer
Answer
Like all empirical formula, the CN method for calculating lag time should only be used within the parameter range used to derive it. Having said that, when compared to other methods for calculating lag time (all of them empirical), the CN method has a better physical basis - in that it is based on the time of travel of water along various flow paths. So, there appears to be no compelling reason why it could not be used for larger basins. I found that the CN method is very reliable and used it for basins as large as 20 km2.
  • asked a question related to Hydraulics
Question
12 answers
Environmental hydraulic engineering is important in China. There are lot's of interesting topic are awaiting for investigation. I hope we form a research team to apply for grants and also share research findings.
Relevant answer
Answer
Our department of Hydrodynamics of wave and channel flows of the Institute of Hydromechanics of the National Academy of Sciences of Ukraine for many years has been engaged in scientific research in the field of shore protection and hydraulic structures. Our employees conduct research work on the study of bridge pier scours and the use of renewable wave energy sources. We have the appropriate equipment, wave and hydrodynamic flumes and channels, a big wave pool on the banks of the Dnieper River near Kyiv. We are ready to cooperate with colleagues from other countries for scientific research in ocean and hydraulic engineering.
  • asked a question related to Hydraulics
Question
27 answers
To me, a CFD is solve a fluid mechanics problem using mathematical approaches with the help of a computer. In other words, it is like a marriage between a mathematical model and numerical methods for solving a fluid mechanics problem.
According to the above, I ask the following questions and answer what I think:
1). Is a CFD a tool to solve only 3D problems?
According to the definition, No. A CFD is not restricted to dimension.
2). Can any software tool that solves a fluid mechanics problem be considered a CFD?
No. I would say that the mathematical model to be solved has to come at least from a simplification of the Navier-Stokes equations.
3). Based on what we understand as a cfd, please mention the CFD softwares you know. For now, exclude the computational algorithms programmed by you.
In 3D: Ansys Fluent; Ansys CFX; Flow3D; OpenFOAM.
In 2D: Iber; Hec-Ras 2D.
In 1D: EPA Swmm.
I would appreciate if you can share your opinions about it.
Relevant answer
Answer
Simply CFD relaxes you from a wide variety of coding for fluid dynamics, particularly for general purposes or in the primary steps of design where coming and experimental approaches are time-consuming or expensive to be employed.
  • asked a question related to Hydraulics
Question
7 answers
Hello Everyone!!
how does accuracy of solution gets affected if i adopt either of FEM or FVM in CFD modelling of fluid flow?
Relevant answer
Answer
There are lot of reasons for the accuracy. Mesh size, representation of governing equation. Numerical is one of the factor in that.
  • asked a question related to Hydraulics
Question
4 answers
I am investigating ways of making sculpture using mid to strong grades of hydraulic lime and volcanic rock dust as the main ingredients to make casts from found shoreline objects. .
Over a period of many years I have grown to love and appreciate the Norfolk coastline and I am planning seven walks along some of its shorelines. The first of which began at Holme-Next-the-Sea in Norfolk, UK, where two bronze age wooden 'Sea Henges' or 'monuments' were were discovered. One of which was contraversially unearthed to be preserved.
My interest in lime for the casting process, stems from its lower Co2 emmiting credentials during its manufature and its durability over time when prepared using similar techniques to making Roman Concrete.
Relevant answer
Answer
i have not got that far yet and things have got delayed a bit with Covid 19. I am hoping toexperiment with pozzolanic volcanic ash from garden centers (provided it is pure, so far so good). However I am struggling with out access to Fascilities right now. my next unit has been theorized to a large degree and Exhibitions are incresingly on line. I would like to put Sculptural works out there as a kind of Antethesis to everything in the current climate. Sorry for the Slow reply-had quite a lot of things to sort out with works and my course.
  • asked a question related to Hydraulics
Question
8 answers
What would be the implications of an unanticipated drastic rise in the water surface elevation in the inlet channel upstream of an inverted siphon with all the rest design parameters (e.g. discharge, downstream water elevation etc) remaining the same as considered in the original design? What kinds of malfunctions would affect the siphon's operation in that case?
Relevant answer
Answer
It is could be causes the flooding in the inlet structures of the inverted siphon as well as increasing the inlet velocity of the hydraulic structures.
  • asked a question related to Hydraulics
Question
3 answers
Hello Everyone!!
Hope everyone is safe in this era of Corona Virus and taking proper precautions to fight against the pandemic.
Let me come to my question. I need hydraulic pump which is to be used in scrap shearing machine to apply 30 MPa pressure on the scrap to be sheared. For this, I need to pump fluid at pressure 3000 psi and flow rate around 250 litre per minute.
Please help me in selecting the best pump for my purpose.
If possible please give reason for selecting particular type of pump like vane pump, piston pump etc
With many thanks.
Vipesh
Relevant answer
Answer
Selection of type of pump is based on specific speed of the pump. First have the data like flow rate, head, no of stages based on Ns value, type of fluid, temperature, etc. Standard specific formula can be used for calculations. Positive displacement type pumps are meant for High head low flow and centrifugal type are good for low head and high flow applications.
  • asked a question related to Hydraulics
Question
6 answers
Hello Everyone!!
Hope everyone is safe in this era of Corona Virus and taking proper precautions to fight against the pandemic.
Let me come to my question. I need hydraulic pump which is to be used in scrap shearing machine to apply 30 MPa pressure on the scrap to be sheared. For this, I need to pump fluid at pressure 3000 psi and flow rate around 250 litre per minute.
Please help me in selecting the best pump for my purpose.
With many thanks.
Vipesh
Relevant answer
  • asked a question related to Hydraulics
Question
10 answers
Currently, I am working on a Remote sensing-based approach for capacity estimation of a reservoir. for comparison purposes, I want to mention the expenditure of the hydrographic survey approach against the remote sensing approach.
Generally, the reservoir authorities require consultancies to carry out the hydrographic survey which is accurate and expensive, Remote sensing approach provides this survey with free of cost.
Relevant answer
Answer
Please ReF:
Hydrographic Survey methods for determining reservoir volume by Jordan Furmans and Bamey Austin 2008. Enviornmental Modell software.
  • asked a question related to Hydraulics
Question
2 answers
Dear colleagues from Chemical, Civil, and Environmental Engineering,
Did someone find actual hydraulic residence times (HRT) greater than nominal HRT in residence time distribution (RTD) experiments whit biological wastewater treatment?
What are the probable causes, besides fluid recycling? We got excelent recovery rates of the tracers (around 90%).
Many thanks in advance!
Relevant answer
Answer
Up.
  • asked a question related to Hydraulics
Question
4 answers
Does the hydraulic diameter of a porous media heat exchanger depend only on the porosity and the wire diameter? Doesn't the shape of the conduit affect the hydraulic diameter? i.e; if the wire mesh is arranged in an annular shape rather than a pipe, wouldn't it affect the calculations for the hydraulic diameter?
Relevant answer
Answer
Heat transfer occurs at the surface and the flow depends on the fluid flow conditions. If we consider the macro-geometry as for instance a pipe in which you place the bundle of wires the conditions at the wire surface on which depends the convection are function of the micro-geometry i.e. the free spaces BETWEEN the wires since the fluid contact is WITH the wires.
It is a question of definition , for different reasons this formula was the choice. It has a logical basis since in the definition of the hydraulic diameter for a section of a not circular geometry dh=4*A/P , the free area for the fluid flow is proportional to "porosity" and the wet perimeter is proportional to the rest of the area thus the higher the porosity the higher the free area and lower the wet perimeter and the higher the hydraulic equivalent diameter.
You can of course use general equations and consider how the wires do touch.
When you apply a formula you should be careful that you have same conditions if not it will loose its validity.
  • asked a question related to Hydraulics
Question
16 answers
There are several types of power plants like: coal fired power plant, gas fired power plant, Hydraulic power plant, Nuclear power plant, Wind power plant, solar thermal power plants etc. Which type of power plant has maximum efficiency?
Relevant answer
Answer
Large scale hydropower plant has compepetive efficiency with gas turbine power plant
  • asked a question related to Hydraulics
Question
4 answers
I am making a model using the program Processing Modflow.
Currently I have a certain defined grid which is my area of research.
The only information I have on hydraulic heads are a fixed head in the northern edge of the grid and constant heads one kilometer below (south of) my grid.
Is there any way to incorporate values that are not assigned to any cells of the grid?
Relevant answer
Answer
it’s better to estimate a flux from the southern boundary (results of the head gradient that is assigned to the ‘’regional model’’). After that you can use this ‘’estimated flux’’ as the southern boundary. The set up of a fixed head boundary in the north and in the south boundary allow the model to supply an unrealistic water quantity especially during transient state and when there is pumping.
  • asked a question related to Hydraulics
Question
1 answer
Dear colleagues,
Based on our successful experience in establishing the SWIG database on infiltration data, we decided to initiate another project to collect soil hydraulic properties and their metadata. Currently available databases that provide estimates of the soil water retention curve and the hydraulic conductivity curve use pedotransfer functions that do not include information about the structural properties. We are therefore seeking original soil hydraulic data (soil water retention curve, hydraulic conductivity curve, and air permeability) obtained on undisturbed soil samples and their corresponding soil properties (e.g. texture, carbon content, bulk density, taxonomic and land-use information) as well as quantitative and/or qualitative information on the soil structure. These structural data may include:
. Taxonomic information (Blocky, granular, or etc.)
. Ksat on undisturbed soils
. Pore size data (obtained e.g. from nuclear magnetic resonance (NMR) relaxometry)
. Aggregates stability
. Geometric mean or mean weight diameter (GMD or MWD) of aggregates
. Fractal dimension .
. Mechanical resistance or etc.
Any metadata describing the experimental data in more detail are welcomed. Data may stem from lab scale, plot, field and catchment scale experiments. We are planning to establish a database of these data that we will submit to a data journal (e.g. Earth System Data Science or any other suitable journal). In order to honor your support, we would like to include you as co-author on the manuscript. We hope that you will contribute to this initiative and welcome any questions you might have.
Please use the enclosed template file (excel file) to share data with us.
We would also appreciate if you could kindly distribute this request to colleagues that might be interested in contributing to this effort.
Our published article in SWIG database is provided in following link for those people who we have had no luck to have their supports for that project.
Best regards,
Mehdi Rahmati (mehdirmti@gmail.com)
Harry Vereecken (h.vereecken@fz-juelich.de )
Lutz Weihermüller (l.weihermueller@fz-juelich.de )
Relevant answer
Answer
Yes, your answer is in the article
  • asked a question related to Hydraulics
Question
5 answers
I have completely done the model of electrical system which is analogous to hydraulic water tank system. But i am having the problem to find the values of electrical parameters (resistance, voltage and current). Please help me regarding this issue.
Relevant answer
Answer
Dear Vishal,
The electrical element which mimics the water tank system is the electrical capacitor. The water quantity in the tank can be mapped to the electrical charge on the capacitor. The voltage of the capacitor mimics the water height in the tank.
The current flowing in or out of the capacitor represents the water flow rate to or from the tank.
This is the analogy between the electrical systems and the hydrolic system.
Best wishes
  • asked a question related to Hydraulics
Question
4 answers
I have completely done the model of electrical system which is analogous to hydraulic water tank system. But i am facing the problem to find the values of electrical parameters (resistance, voltage and current). Please help me regarding this issue.
Relevant answer
Answer
as per my perception,
current may be analog to hydrostatic pressure,more at bottom of tank
resistance analog to leakage through tank
voltage analog to uplift pressure
  • asked a question related to Hydraulics
Question
14 answers
Which of the two is better in terms of output ?
Relevant answer