tamim

AdH for Beginners

6 posts in this topic

I've been using WMS for several years but I am new user of SMS, specifically, the AdH program implementation.

Recalling that the learning curve is pretty substantial from my experience with WMS, I've gone through a similar self-taught process of going through the SMS and AdH User Manuals, Learning Center tutorials, video and SMS Wiki.

I did follow the AdH Intro tutorial and successfully setup the model and executed it. However, after 1 hour of simulation time (out of the 36 hour) and a run-time of 3 hours, I aborted. The tutorial indicates that depending on the speed of your computer, the model will finish in 1 - 2 hours. My laptop is a Dell Latitude, 16 GB RAM, Intel Core i7 processor with plenty of disk space. Is this a hardware limitation or an issue of computational settings (which I left to default just like the tutorial)?

The above resources helped me setup my model. I imported a AutoCAD .dwg file and created scatter points from the contours & created a mesh, which turned out to be extremely dense due to the excessive vertex points SMS generated as a result of the AutoCAD contour vertices. So as an alternative, I manually defined scatter points along known elevations/contours at a less refined spacing. I generated a mesh which looked much better in terms of shapes and density.

I was able to define the materials designated on the basis of channel, overbanks, and paved surfaces and correspondingly defined the boundaries based on these designated areas. I created nodestrings to define the upstream and downstream boundary conditions as Total Discharge and Water Surface Elevations, respectively, that varied for a 6 hour simulation. I created the AdH Hot Start (depth/elevation).

When I ran the AdH Model Check, it gives me the triangle bad aspect error (17 in all). Following the recommendation, I went back to change the aspect ratio from the default 0.04 to 0.1 and regenerated the mesh, which gave me even more bad aspect triangles. I couldn't manually merge triangles or convert them to quadralaterals. Is option available for AdH models?

I've been spinning my wheels for the past couple of weeks, so I am officially stuck and in need of some guidance from experienced users and/or developers.

Sorry for the verbosity & appreciate any constructive feedback,

Tamim

Share this post


Link to post
Share on other sites

ADH is an advanced model that takes a lot of time to figure out what works and what does not work. I have found that ADH can take a long time to run and I mean a really long time, if it is not set up properly. In general I like to to scalar density paving to generate my mesh and then modify it as needed (adjust nodes/elements to get rid of bad elements and refine if I need more). I also try to limit the number of elements and make them as big as possible as the automatic time step option for ADH does not always help and sometimes you just need to use a constant time step. I have also found that if you turn on adaption, it can increase the run time dramatically and so I usually refine my mesh enough and not use adaption. One of the most important things for ADH is to have a good hotstart file and there are times that I have used another 2D model to generate the hotstart file (SRH-2D and others).

Cheers,

Cameron

Share this post


Link to post
Share on other sites

On a side note, you can also set up ADH to run with multiple processors which is what I recommend as it can help with run times.

Share this post


Link to post
Share on other sites

Cameron,

I really appreciate your thoughtful responses. I've been trying to apply your suggestions, with limited success.

I had applied the density paving to generate my mesh (5100 elements) but I did just turn the adapt option off, which did improve run times. However, it is still running at a absurdly slow rate of 1 sec / 1 hr (simulation/run time). It really seems far too precise to use a time step of 0.0002 sec. I recall running 10,000-cell models with FESWMS on a Pentium II, which would converge in a few hours. I've been using the constant depth option for the hot start, which I am certain probably doesn't help with

The next two of your suggestions that I am plan to try is the more coarse mesh and the multiple processors, the latter I am not sure how to accomplish. Does it require more than one computer or another processing chip? I have an Intel Core i7-3540M (3 GHz) processor on a Dell with 16 GB RAM and plenty of disk space, which has been very fast for all my GIS, CAD and WMS (with huge DEMs) applications, so my only conclusion is that AdH is extremely computationally dense.

Thanks again for your very helpful advice and feedback,

Tamim

Share this post


Link to post
Share on other sites

The hotstart file could be the culprit. If you are willing to share the files I can take a look.

To apply the multiple processor option, ERDC gives the following guidance. Basically you need to install the SDK and then in the dos command prompt type in: mpiexec –n “processors #” adh.exe “filename”

the file name is the adh input file that is created in sms.

Multiple Processor Execution:
A 64 bit Windows multiple processor version of AdH is now available. To utilize
this capability you must have the HPC Pack SDK from Microsoft installed on
your machine. We are unable to entertain requests for multi processor executables
for other operating systems such as Mac OS, Linux etc. The generic command
line for executing the Windows version is:
mpiexec –n “processors #” adh.exe “filename”

Share this post


Link to post
Share on other sites

Cameron,

I very much appreciate your feedback and willingness to share some of your experience.

I downloaded the components of the Microsoft HPC Pack SDK but it keeps giving the error that it needs to be installed on a local hard drive (the default directory is C:\Program Files\Microsoft HPC Pack 2012\). I'll see if I resolve this issue and install it.

I'd be more than willing to share my data files for my model. there are several permutations that I tried to get it to run faster but 1 sec / 1 hr was as fast as I could get AdH to execute. Please provide me your preferred email address. Mine is tatayee@rivertec.com

Thanks very much,

Tamim

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now