[LukaD]

For my thesis project, I recently ran into a lack of computational resources on my trusty old laptop. As it took some time to get access to the CFD cluster at the faculty, I started exploring other avenues. One of the solutions I found was Rescale.com, a company that offers cloud computing resources and has OpenFOAM pre-installed on their servers. They offer some free computing time if you sign up for their trial, so I went with that. However, it took me quite some time to get things running, so I wanted to offer some help here for anyone trying to do the same thing.

If you simply want to run with the standard OpenFOAM setup, the process is very simple. Create a new job and select the hardware you want to use. Then create a .zip archive of the case you want to simulate (i.e. of the 0, constant and system directories, as well as any other supporting files). The easiest is to use an Allrun file that contains all the commands you want to execute. Now upload this .zip archive as input file. Choose OpenFOAM as software and fill in ./Allrun as the command to run. If you execute the job now, it will simply run the OpenFOAM case for you.

Using custom solvers and executables is also straighforward. Simply add the executable to the .zip archive you upload and it should work. Custom libraries are somewhat more difficult. First, create a new directory called "lib" in your case directory. Add to this directory all custom libraries you want to use (e.g. some swak4foam libraries you need). Now we need to tell the server where to find these libraries. The solution is to add the following line to the start of the Allrun file:

export LD_LIBRARY_PATH=$PWD/lib:$LD_LIBRARY_PATH

This line adds the directory you just created as the first path the server checks when looking for a library. In this way, you not only can access these libraries, but they also take precedence over standard OpenFOAM libraries, e.g. when you created your own thermophysicalFluid library like me.

So far, I'm quite happy with the results as the calculations are approximately 4x faster than my own computer.

Note: I am not affiliated in any way with Rescale, I just wanted to offer this short guide because the problems I encountered had, in retrospect, very simple solutions.

[kalyan]

HI luka,

I am trying to implement my custom solver in Rescale.com . I uploaded my solver and in Allrun file i wrote wmake. In log file i get wmake command not availabe.. I tried to compile also with wmake libso.. got same error. Could you give me your input how to implement my solver in rescale.com

[LukaD]

You don't have to compile it on the server; just upload your own compiled version. That one is usually stored on your computer under your personal directory/platforms/linux64GccDPOpt/bin (or lib for libraries).

[kalyan]

when i upload should i zip in, the case i want to simulate along with it? or can i submit my case as another job? Thank you luka

[LukaD]

You should include the executable (the file in /bin) in the zip file of the case you want to simulate.

Then if you call

myCustomSolver

the server will go looking for the myCustomSolver file and execute it.

[kalyan]

Thank you.. Its working