Software

[dik]

Is there a free/inexpensive, relatively easy to use three dimensional FEM flow program that hydraulic structures can be modeled?

What 3D FEM programs are commonly used?

thanks, Dik

 

[Ryb01]

Is there a reason why you would want to model in 3D?

Hec-Ras is the most widely accepted hydraulic modelling software in north america. You can download at the following site

http://www.hec.usace.army.mil/software/hec-ras/hecras-download.html

Hope this helps.

 

[cvg]

you might try the structural engineering forum for this. HEC-RAS is for hydraulic modeling, not structural FEM

 

[dik]

cvg:
I was looking for hydraulic modelling, not stress analysis. Any suggestions?

thanks, Dik

 

[cvg]

2D programs are available for hydraulic analysis of drainage across land but is not very good for structures. See FLO-2D for an example and there are others. Most of the hydraulic theory for drainage structures is simplified for a 1-dimensional analysis and frankly 3D analysis would probably be overkill. HEC-RAS (River Analysis System) is good for rivers and channels including bridges and culverts. But most other types of structures are not handled particularly well with HEC-RAS. And HEC-RAS is 1D, ie: flow goes one direction only.

 

[tsgrue]

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There are several free ones listed at "

http://hhwq.blogspot.com/".

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tsgrue: site engineering, stormwater
management, landscape design, ecosystem
rehabilitation, mathematical simulation

http://hhwq.blogspot.com

 

[cvg]

tsgrue - Excellent site but I don't see any 3D hydraulic modeling software on there - except for groundwater. I do see a couple of 2D or quasi 2D models.

 

[tsgrue]

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Well, you're generally correct there. (I should have checked specifics before posting). GETM is listed and, obliquely, so is CCHE3D (NCCHE). For geomorphologic studies, you might consider the MD_SWMS (Multidimensional Surface-Water Modeling System) from USGS. I think you may actually be referring to what is commonly termed CFD (Computational Fluid Dynamics) rather than FEM (Finite Element Modeling). Check out "

http://www.cfd-online.com".

OpenFlower, OpenFOAM, Gerris Flow Solver, OpenFVM are examples of free CFD codes, but generally not with much more than a basic pre and post processor, if that. Fluent from ANSYS and FLOW-3D from Flow Science are two commonly used commercial codes. Some other ones are freely available from NASA and USACE (US citizens only, I think). But, this stuff is pretty complicated for the uninitiated. Most folks need graduate engineering mathematics and modeling coursework to successfully undertake CFD modeling work with these systems and - even then - the process can be quite time consuming. Beyond that, your simulation might simply be incorrect! CFD is not something that 99.999% of engineers would pursue (or need to pursue) - that's 1 in 100,000!

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tsgrue: site engineering, stormwater
management, landscape design, ecosystem
rehabilitation, mathematical simulation

http://hhwq.blogspot.com

 

[dik]

Thanks tsgrue, it could be CFD... I have used FEM to model strange stuff, and just assumed that water (as a continuum) could be modeled as such... I'm not up to speed with hydrodynamics. I'm looking at determining flow patterns around hydraulic structures (for my own interest and as part of a project (other skilled people will be doing the design))

Dik