Objective function

[Charly-28]

Hello,
I have a few questions regarding Dafoam's capability.

1. Is Dafoam able to do multi-objective obtimization? For example the thrust (force on a propeller) and the torque.
2. Could we do an aeroacoustic optimization? I think that for this question it will be necessary to create an objective function.
3. How integrated a new objective function in DaFoam?
   Thanks for your help.

Charly

[friedenhe]

1. Yes, it is very straightforward to set up multi-objective optimization in DAFoam, check this, it is a multi-objective setup with total pressure loss and heat transfer. You can follow it to define an objective function that has multiple parts, part 1 could be the thrust, and part 2 could be the torque. Remember to give them proper weights.
2. No, we don't have an acoustic model in DAFoam yet, but you are welcome to add such an objective function.
3. To add a new objective function, you need to add a new child class in src/adjoint/DAObjFunc to implement how to compute this objective function. Refer to the implementations for other objective functions.

[hosseinnegahban]

1. Yes, it is very straightforward to set up multi-objective optimization in DAFoam, check this, it is a multi-objective setup with total pressure loss and heat transfer. You can follow it to define an objective function that has multiple parts, part 1 could be the thrust, and part 2 could be the torque. Remember to give them proper weights.
2. No, we don't have an acoustic model in DAFoam yet, but you are welcome to add such an objective function.
3. To add a new objective function, you need to add a new child class in src/adjoint/DAObjFunc to implement how to compute this objective function. Refer to the implementations for other objective functions.

Hi,
Could we add this new class in DAFoam image or we have to install it from source?
I want to add the lift to drag ratio objective function. I would appreciate it if you help me in this regard.

Thank you
Hossein

[friedenhe]

You have to implement it by youself! We will have a workshop this summer to talk about DAFoam code development. Feel free to join if you are interested.

[Charly-28]

Thanks for the answers. They will help me especially for the implementation of objective aeroacoustic functions. I have another question concerning the instalation.

1. Is Dafoam compatible with the recent version of OpenFoam (Openfoam v2012).
2. Could it be installed on Ubuntu 20.04 or the most recent version?
   Thanks

Charly

[friedenhe]

Nope... we don't support OpenFOAM-v2012. And yes, you can compile dafoam on Ubuntu 20.04. We just updated the installation guide for Ubuntu 20.04. There is only one minor change when installing Miniconda.

[Charly-28]

Thanks for your reply.
But I have a problem installing numpy 1.14.3. Do you have an idea?
Below are the installation errors:

pip install numpy==1.14.3
Collecting numpy==1.14.3
Using cached numpy-1.14.3.zip (4.9 MB)
Building wheels for collected packages: numpy
Building wheel for numpy (setup.py) ... error
ERROR: Command errored out with exit status 1:
command: /home/kone/dafoam/packages/miniconda3/bin/python -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/tmp/pip-install-_l2h8yrn/numpy_ef83e22b66a44ffcad649a884a9864d8/setup.py'"'"'; file='"'"'/tmp/pip-install-_l2h8yrn/numpy_ef83e22b66a44ffcad649a884a9864d8/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(file);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, file, '"'"'exec'"'"'))' bdist_wheel -d /tmp/pip-wheel-rgge2how
cwd: /tmp/pip-install-_l2h8yrn/numpy_ef83e22b66a44ffcad649a884a9864d8/
Complete output (307 lines):
Running from numpy source directory.

Thanks for your help.
Charly

[Charly-28]

Thanks for your reply.
But I still have the same mistakes:

./runTests_DAPisoFoamACTL.py

It looks like opal_init failed for some reason; your parallel process is
likely to abort. There are many reasons that a parallel process can
fail during opal_init; some of which are due to configuration or
environment problems. This failure appears to be an internal failure;
here's some additional information (which may only be relevant to an
Open MPI developer):

opal_shmem_base_select failed
--> Returned value -1 instead of OPAL_SUCCESS

[friedenhe]

Did you load loadDAFoam.sh before running the job? Run these and let me know what do you see:

which python

which mpirun

python and then import mpi4py and then mpi4py.__path__

[Charly-28]

1. Yes I load loadDAfoam before running job.
2. which python
   ./dafoam/packages/miniconda3/bin/python
3. which mpirun
   ./dafoam/OpenFOAM/ThirdParty-v1812/platforms/linux64Gcc/openmpi-1.10.4/bin/mpirun
4. python import mpi4py mpi4py.path
   ['/home/kone/.local/lib/python3.7/site-packages/mpi4py']

Question:
How to use mpi4py without uninstalling it locally?

Thanks

[friedenhe]

Add this line to your loadDAFoam.sh and re-load it. It will bypass the packages in .local

export PYTHONUSERBASE=no-local-libs

[Charly-28]

Thanks for your reply.
Now the test works but failed on the solver interfaces
Below the error:

[[55182,1],0]: A high-performance Open MPI point-to-point messaging module
was unable to find any relevant network interfaces:

Module: OpenFabrics (openib)
Host: kone-HP-Z4-G4-Workstation
Another transport will be used instead, although this may result in
lower performance.

DASimpleTFoam: Failed!

[Charly-28]

Thanks for your reply.
Now the test works but failed on the solver interfaces
Below the error:

[[55182,1],0]: A high-performance Open MPI point-to-point messaging module
was unable to find any relevant network interfaces:

Module: OpenFabrics (openib)
Host: kone-HP-Z4-G4-Workstation

Another transport will be used instead, although this may result in
lower performance.

DASimpleTFoam: Failed!

[Charly-28]

Thanks for your reply.
Now the test works but failed on the solver interfaces
Below the error:

[[55182,1],0]: A high-performance Open MPI point-to-point messaging module
was unable to find any relevant network interfaces:

Module: OpenFabrics (openib)
Host: kone-HP-Z4-G4-Workstation
Another transport will be used instead, although this may result in
lower performance.

DASimpleTFoam: Failed!

[friedenhe]

Ignore this, this is a test bug on Ubuntu 20.04, but it shouldn't impact the optimization results. Try to run a tutorial.

[Charly-28]

Now all is fine.
Thank you for your availability I will contact you for the aeroacoustics.
My current project is to optimize the thrust and engine torque coefficients.
Maybe I'll need your help.
Thanks for your help.

Charly