4.18.3. Running FAST.Farm

As FAST.Farm is a module of OpenFAST, the process of downloading, compiling, and running FAST.Farm is the same as that for OpenFAST. Such instructions are available in the Installing OpenFAST documentation.

Note

To improve the speed of OpenFAST compiled with FAST.Farm enabled, the user may wish to compile in single precision with OpenMP. To do so, add the -DDOUBLE_PRECISION:BOOL=OFF -DOPENMP=ON options with CMake.

Note

Checkpoint-restart capability has not yet been implemented within FAST.Farm.

4.18.3.1. Troubleshooting

4.18.3.1.1. Segmentation fault at start

Very large FAST.Farm simulations may experience a segmentation fault if insufficient stack memory is set aside for OpenMP. This may appear on simulations with more than 50 turbines spaced over tens of kilometers. If this is the case, the fault is likely to occur right after screen displays the T=0 timestep.

To increase the stack assigned to the OpenMP process on linux based machines, the environment variable OMP_STACKSIZE can be increased from the default 4 MB (Intel compiled) to 32 MB (or more) by

export OMP_STACKSIZE="32 M"

If this solves the segmentation fault, then the root cause is from the parallelization with OpenMP not having sufficient stack reserve. If this does not solve the issue, then there may be other problems that should be reported.

For further reading on segmentation faults with OpenMP, see stackoverflow comment and Intel OpenMP documentation.