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# Hydraulic Engineering - Science topic

Explore the latest questions and answers in Hydraulic Engineering, and find Hydraulic Engineering experts.

Questions related to Hydraulic Engineering

As it is noticeable, there are several research projects with regard to using of cavitation and the production of bubbles for friction reduction in ship movements. I want to understand the mechanism thoroughly for this process. Also, how much is it practical for decreasing fuel consumption?

Best regards,

Hossein Pouresmaeil

https://www.researchgate.net/project/Ancient-Hydrological-Knowledge-and-Old-Hydraulic-Structures

_{ }Article L'aqueduc de Carthage

Can we share information about ancient hydrological knowledge, old hydraulic techniques, and ancestral water management methodsI am doing a project related to screw turbine, in which I am supposed to analyze the screw rotation, when the flow speed of the water is 2m/s. For this I prepared a model in soldworks and use the ansys fluent to solve the governing equation. I used the dynamic mesh with cell height equal to my mesh size(0.05m). I used the transient analysis. The screw doesn't seem to rotate when studied in the cfd post.

Pardon me if the problem statement isn't clear. I am a beginner.

I´m trying to get an optimal reservoir operation rule in a multireservoir system where some reservoirs have carryover storage. I had developed an operation model based on Kritski and Menkel´s method and uses generalized Storage - Reliabiliy-Yield relashionship. This model has been tasted and implemented in single reservoirs but not in a multireservoir system. I want to know if there are other carryover storage methods that have been implemented in a multireservoir system.

Thank you.

Hi

In some studies we need to calculate the main channel length/slope of a certain river.

For example you can see a real catchment in uploaded pic with it's main river and tributaries.

Now, I have some questions:

1. What is the definition of main stream channel of a river and how can we determine it using ArcGIS?

2. If you want to calculate the main channel length, In the appended pic, which one is your choice as the main channel (Black one or Red one?)

Can we suppose the longest channel stream as the main stream?

3. Is there any tool in ArcGIS to calculate the length and slope of stream channel?

Thanks

Hello,

I am working on bigger project. The project includes many subbasins that have to be considered. We are working each on one subbasin at the time. Input is effective precipitation.

Our simplified workflow with SI units is:

1. Modelling terrain (.tiff) Terrain with coordinate system

2. Subbasin border (.shp) 2D Flow area base cell spacing (bigger)

3. Hec ras mapper

3.1 2D FLOW areas edit add breaklines for roads, railways, riverbeds. Adjust cell spacing (smaller). Enforce breaklines.

3.2 2D FLOW Refinement regions

4. Adding unsteady flow data Precipitation, Normal Depth as downstream boundary.

5. Running model Unsteady flow analysis with computation settings

6. The »right/validate« result is calculated.

And now comes the error. After opening Hec ras mapper to view result we get notification of »

**Error in Loading Geometry data**« The geometry section of 2D Flow Areas gets red dot. Breaklines, refinement regions, boundary condition lines are lost. On the left down corner we get the error “**Fail to Load. Start Editing to Recompute Mesh**”. This error has begin to appeared after the half of basins were done. Now even the finished subbasin are getting the same error. Did anybody encounter similar problem? What am i doing wrong? Any help is appreciated.it means the oil pump to be sometimes able to turn off during the driving cycle, and if it is possible, how efficient would it be? (more particularly in heavy vehicles like a bus).

Dear Sir,

When we conduct a fixed bed hydraulic model for an actual river reach model, we have to set up the artificial roughness on the fixed bed such as bolt/nuts to be spaced scattered. In the propto type, of course, we have a roughness as the calibrated or designed values as manning values.

Are there some guideline (in English literature) on how to convert the manning roughness value to the artificial roughness parameters ?

Thank you

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?

Currently, the combined effect of all clouds is one of net cooling, meaning that clouds are dampening the rate of climate warming. But scientists are looking into whether clouds will have the same effect on climate as the Earth continues to warm.

**If the proportion of different cloud types changes, it could affect the rate of climate change because different types of clouds have different impacts on the Earth's climate. While some types of clouds help to warm the Earth, others help to cool it?**Can anyone help direct me to papers or books about trash screen or debris mangment?

Dear Researchers

According to your practical experience, which formula, out of the following three, is more reliable for calculating head loss in water supply pipes and provides better results when compared to the actual values?

Hagen–Poiseuille

Darcy–Weisbach

Hazen–Williams

Hi.. What is the best MATLAB text book that is most suitable and full of solved examples to teach students how to solve applications of thermal engineering using

**Simulink**?I need to simulate the transition of Flow through Coarse Porous Media such as Rock-fill dams, to investigation of Water level profile in each distance from up-stream and determination of discharge of fluid seepage from the body of these media. Notice, I want to simulate a Single-Phase Flow.

How can I simulate this project? Please suggest and introduce a useful software for this issue to me...

What is your idea about Flow 3D, Fluent, ABAQUS,...

Conference Paper A numerical study of the flow through coarse and homogeneous...

Conference Paper Transition of Flow through Coarse Porous Media with Network ...

I designed a

**pneumatic motor(****hydraulicmotor)**in this field and I want to know what the problem is?In a 12-meter-long straight channel, a gate with a pneumatic jack has been employed at about a meter before the butterfly outlet gate (used for adjusting the water height) so that it would be used to generate positive surge. When the gate is closed suddenly (in about 0.2 second), it causes an increase in the flow depth and thus conversion of the flow from steady to unsteady, the fact which results in wave progress. I would like to know whether this type of positive surge resulting from sudden closure of the gate (whether with an approximately 2.5 cm opening, or with a complete closure) could be modeled in a straight channel using Flow3D? what software program may be used for its simulation?

Best regards,

Maryam Akbari

hello everyone!!

we often encounter with the partial differential terms. (partial)dy/dx.

i have shown the exact form of the equation in which i am interested in.

if i have the values of both the variables then how to estimate it.

My work is mainly experiment-based research. Moving a step further in the advanced analysis, can you please help me with the following questions?

1- Do you think this topic is linked with dynamic systems analysis? if yes: how this analysis should be done?

2- What kind of theoretical analysis (based on differential equations formulation) could be added to my research (especially to the vortex's stability and/or stochastic factors)?

3- What's your best suggestion for making sure that the results obtained (from experiments) are dependable? (Validation by CFD?)

Every single answer is important to me.

Thank you very much.

In unsteady open channel flow of storm water networks of circular section, besides the hydrographs entering in each link resulting from the continuity equation and excluding weirs or control devices, frequently the boundary conditions considered are the energy equation in the manholes and the critical condition or the uniform flow condition in the case of a free fall downstream or manhole without influence from downstream. A possible approach that is sometimes considered in design situation considers each link separately and the condition of steady uniform flow in the downstream end of each link, for each flow rate reached in the extremity in any instant of time. What is (or may be) the magnitude of the differences reached with this approximation with respect to the real conditions, assuming, in any case, an open channel flow as should be considered in a design situation?

I require a constant water flow rate of 0.5 LPM/1LPM for my water disinfection system. The flow of water should be constant through out system. Is it possible to control water flow rate without using hydraulic pump?

Secondly, somebody suggest me to use water control valve for constant water flow rate. How can I choose water control valve suitable for my system?

Pipes sometimes are classified as flexible or rigid pipes by checking the vertical deflection-to-internal diameter ratio in which the structural damage of the pipes subjected to parallel plate testing occurs. This control is made with unaided eyes. Do you know of any specific vertical deflection-to-internal diameter ratio associated with the beginning of the damage in which the flexible and rigid pipes are differentiated? Do you know any references for that classification?

hydraulic forging press of 400 ton capacity required how much quantity oil. all the other parameters are known.

Hello everyone!!

I would like to know , How to convert hourly stream flow discharge to daily discharge ?

Please help

I want to calculate the amount of seepage in an earthen dam where the slope is protected with vetiver against stable seepage slope failure. For this I want to know the coefficient of permeability of the soil sample at the slope which is rooted with vetiver. So is there any way to calculate the coefficient of permeability keeping vetiver alive?

AMC is the moisture condition of soil before 5 days actual rainfall.

Hai everyone, I am working of SWAT CUP for my validation and calibration. After doing first calibration , i got the value of NS equals -0.17. Then when i am again doing my calibration again to get the exact value of NS , i am facing an issue that "the application has requested the run time to terminate in an unusual way ". i attached the screenshot of the problem what i am facing now. Can anyone give a proper solution for this , so that i can move further.

Hello every one!!

im looking for the trend of LULC. suppose there is change in Agricultural land then how can i find the trend of it? in the agricultural land, suppose there is particular type of crop cultivation is also changing, how can i capture that trend? in the same line, i'm wondering what would be the resolution of image required to see the changes in particular crop cultivation area?

Hello Everyone

im looking for the discretization tools or techniques or strategy which can be used in the matlab.

I need an output discharge of various flow rates varying from 0.5 to 15 liters/minute at a constant pressure of around 0.7 bar; could you please suggest to me which type of pump can be used to achieve these conditions?

Two plastic tubing are to be connected and glued in perpendicular for fluid flow. Can you suggest any tests that can be done to detect any leakage at the joint?

See attached photo.

I'm trying to find the discharge coefficient (Cd) for an orifice knowing the orifice diameter, the inner diameter of the tubing, and the flow coefficient provided by the manufacturer.

I've tried using the equation

Cv = Cd/sqrt(1-ß^4)

This however returns a number that makes no sense (less than 0.01). I'm expecting for my numbers something in the range of 0.7 to 0.85. Is that the wrong equation?

For example, I know for another orifice that Cd = 0.89, Cv = 0.025, ID = 0.2", orifice diam. = 0.01. That equation doesn't give the Cd I know from experimental data is true.

The orifice I'm trying to find Cd for has Cv = 0.028, ID = 0.20", and orifice diam. = 0.035"

Thanks for your help.

give the method or formula to find the depth -averaged water flow velocity in a rectangular open channel.

We are working on a experimental set-up design to observe fracturing. For experiment we are in search of the best way to monitor the change in fracture width with pressure during fracturing.

when I'm designing a hydraulic system, I wonder the tolerance

of shafts of the motor and pump.Is there an ISO doc tell it or some industrial tradition?

I'm trying to estimate groundwater recharge and I need specific yield to do that. I have read about method of using rainfall data and groundwater levels or linear regression of these two parameters but I do not understand this empirical technique

I am looking for a stochastic model in use clearly for extreme rainfall generation.

the rainfall will be used for hydraulic models and drainage system models.

few concepts are developed in past but it seems there is not any toolkit or software with manual about them, like

Neyman-Scott (NS) or Bartlett-Lewis or DRIP MODEL

thanks

The moving part starts moving once the pump is started and before starting the test.

I am looking for a reference (book, paper...) where to find a clear explanation of the different techniques that can be used to implement boundary conditions for 2D shallow water equations with a finite volume implementation. Can anybody help ? Thanks a lot in advance. Marco

For lifting of objects on the seabed, one must to overcome the mud suction force to allow the object to be lifted. The loads will be immense if pulled instantly. The question is how an initial estimation of breakout force can be made.

Can anyone help me about hydraulic shaft seal testing procedure? I want to test seals in an accelerated stress condition to expedite the test. Is there any standard equipment available to test seals at higher temperature, pressure, and velocity?

For slurry head losses or limiting velocities expressions developing process, it is important to have calibration information, but it is very hard to find works related to industrial (mineral ore) slurries, but very easy to find sand-water slurry data.

I would like if it is there any researcher looking for something similar?

I need to study the main theories and equations about dome design and arch dam design hydraulically and structurally

(i) How does spatial and temporal distribution of radio-nuclide concentration get distributed as soon as it leaches out of the disposal facility, particularly in the near field, and that too, in the absence of thermodynamic equilibrium?

(ii) What is the rate at which the mobility of radio-nuclides takes place soon after its release from the disposal facilities?

(iii) What happens to mixing or spreading details of radioactive wastes within the subsurface system associated with different disposal practices connected with different depths/geology?

(iv) How fast the nuclear wastes gets diluted, especially within deep-seated unweathered hard rock?

(v) In case, if the nuclear waste (or radionuclides) leaches out of the repository, will the concentration of the soluble species such as Cesium and Technetium be diluted to natural background level, and if so, what is the associated rate at which the concentration of radionuclides gets diluted?

(vi) What happens to the concentration of insoluble species such as Plutonium?

(vii) What is the likelihood of leached radioactive wastes reaching all the way to the biosphere from geosphere?

(viii) Whether the concept of nuclear heat associated with the subsurface and deep geological disposal require the transport of thermal fronts with

reference to the transport of solutes?

(ix) How far colloids influence the radionuclide migration? and

(x) Whether NAPL behavior has a significant role to play with, in the vicinity of a Nuclear Waste Repository?

Reference:

ISH Journal of Hydraulic Engineering, 2015, Vol. 21, No. 2, 162–176

Suresh Kumar

I have 4500 images at a single measurements, and each file contain 3970 numbers of u,v,x and y. So it is difficult on part of me to the averaging and to get a longitudinal velocity profile. So kindly help me

Does anyone know any CFD modeling software that can be used for hydraulic computation purpose?

hello Everyone !!!!

i would like to measure velocity of flow in XYZ direction near the surface of pier ,yes we do have ADV and i can measure velocity atleast 7cm away from the surface of pier, so how can i measure the velocity within 7cm radius from the pier ?

Would appreciate research comprising sustainable and cost effective weir design solutions.

Hi, when I analyze the small sphere fall in still water with acceleration, is there a suitable equation to illustrate its relaxation time on the sphere velocity? Thank you in advance!

I am doing an experiment in a hydraulic flume to study velocity field and flow structure in vicinity of a retaining wall. I am using PIV and currently looking for a way to shoot laser from top of the free surface (to study flow structure under the free surface) without putting plexi glass or any other material which may pressurize the flow. Any idea or suggestion?

I want to calibrate the daily sediment data by using SWAT-CUP.

I don't found the exact format of daily observed data to edit into SWAT-CUP and so that the calibration process is not completed.

Kindly provide the exact FORMAT for "DAILY OBSERVED DATA TO BE USED IN SWAT-CUP.

Thanking you.

i would like to learn about the calculations formulas involve in this mechanism.

Any notes or formulas with explaination on the calculations of pressure loss, volumentric velocity, velocity, ect. will be very much helpful.

In the pdf of the given link, the hydraulic loss coefficient was not clear to me.

at the end results, i want to learn how to determine a right conical vortex regulator size when i have a wanted pressure loss, velocity ect.

If there´s a price range for the conical vortex regulator according to size..it will be very much helpful too.

i want to solve this system of ODE, i.e, solving two equations simultaneously...

what method would you recommend me?

please explain your recommended method.

thanks

I'm interested in measuring the temperature of the snow over its depth. The temperature should be measured in every 20-25 cm over the up to 2 m snow pack.

Have Regime Equations in designing canals usefulness?

BUT Take into account that canals have routine maintenance program or growing of vegetation

The wastewater from a restaurant (about 40 m3/day) enter to an equalization tank (dimension W*L*H= 1*3*4 m) before an anaerobic system.

What is your idea and experience about the installation of a non clog pump in equalization tank for discharge waste water to an ABR?

Is it possible to have a pump with differential discharge or regulation ability, for example 0.5 untill 3 m3 per hour. Off course we can install a fixed discharge pump, with a bypass flow to the system for regulating the outlet flow.

What is your idea for the type of pump and required power?

If you have any experience or design for the same condition, please write your idea for this design.

thanks for your reply

Is manning equations the best method to determine the discharges in open channels?

Can anyone help direct me to papers or books about River island formations?

is it possible to calibrate the swat model to estimate sediment yield without observed data?

Swat model calibation for unguauged watershed?

Pls guide me..

Thanking you

if any one have papers in yhdraulic field past than 1950 ?

I am performing simulation analysis for an agricultural vehicle HST control system. I need to obtain temperature variated flow rates for its pumps and motor. It is known that volumetric efficiency decreases with temperature and hydro mechanical efficiency follows the opposite trend. Can I obtain a mathematical basis for this for general test conditions , so that I can quantity and build simulation models based on this relationship.

dear all :

am looking for the hydraulic details for culverts or extra details for the purpose ( using flushing culverts ) in the body of the breakwaters in harbor connected with the basin for improving water circulation at the basin.

I would appreciate any advises, helps, recommendations.

thank you

I have broblem with understandig what exactly is the parameter R ?and can we show it in the control volume?

if you help me with this i will be very thankfull.

Is it specific to the composition of the anolyte and desired outcome? Or is there a general value?

How can I calculate the minimum length of overflow spillway without routing calculation?

It is assumed that to be a two stage system, the HRT should be greater in the acidogenic reactor because the hydrolysis step is which required most time.

The conventional rational method or its derivate is still very used for dimensioning and calculating separate urban storm water networks. What are the main reasons for the use of the classic formulation to be normally limited to small drainage basins? The conventional method overestimates or underestimates water flow rates? Is it safe or insecure? The water flow rates for the dimensioning and the calculation of the networks should be increased or decreased?

hi

how can I Calculate head loss of a drop manhole?

is any design chart or solved example for it?!

Thank

I am looking for Moritz Weber's theory and experiment to determine the Weber number.

How much artificial aeration methods, such as constructing cascades or weirs, using mechanical aerators, floated plants, or pumping out and discharging again the water, can increase the rearation rate (Ka) of rivers? Is there any practical case study pointing to this fact?

I know that this depends on various parameters, and I dont need the aeration potential of these methods. I am really looking forward to any literature, case study or report that directly shows Ka is changed from X to Y in rivers.

I am currently designing the hydraulic system of a refuse compactor vehicle. I'm having a problem in choosing the correct method to choose the best working pressure and temperature in order to produce high efficiency.

Can any anyone suggest any method or model to optimize energy production in Hydropower plant?