Can ROM Builder be able to simulate/predict different geometric parameters?

kaboka · February 15, 2022, 03:55

Hello everyone,

I am working on a Diffuser's CFD model which I would like to solve with different diffuser angles and inlet velocities.

However, I cannot select the diffuser angle parameter, which I had defined in DesignModeller, in DoE of 3D-ROM.

I would appreciate it if anyone has any ideas or links to examples.

Bests

LoGaL · February 16, 2022, 08:52

Hi kaboka,

Having back in the days tested the very early version of the ROM builder which was provided me by the developers, I can confirm you 100% that this is not possible. Different geometry = different Mesh, in particular, also different number of elements.

What the ROM does is building a reduced order model (ROM) of the variables of interest for each mesh element, based on the value of such variables provided by the different solutions you use to train the model.

In case the mesh changes, it is a bit weird

In theory, it could be possible to obtain a ROM in a part of the domain which is not changing, provided you also, somehow, manage to obtain the same mesh there, but I do not believe it is something possible with the current release version.

kaboka · February 16, 2022, 09:18

Hi Lorenzo,

Thanks a lot for your answer. Now it's more clear that it's not quite possible.

As I found a developer, one more question that's in my mind is the reduced-order model of transient 3D CFD simulations in ANSYS Workbench. I can easily generate a ROM model of a 3D-CFD steady-state simulation but for transient, I heard that's a bit hard in ANSYS, or do I need to buy the Twin Builder Licence for the Dynamic ROM Builder? If you had any roadmaps, that would help a lot.

Bests

LoGaL · February 16, 2022, 12:02

Bear in mind, I was no developer, I just happened to test a very early version for my company. We where interested in using it for combustion applications.

Back in the days it was only possible to generate Roms for steady simulations. I am not sure if then they added the possibility to do it for unsteady runs.

For time averaged flow fields of unsteady runs, it should be easy to generate Roms..... If you want instead "time resolved" Roms, I am not sure.

February 15, 2022, 03:55	Can ROM Builder be able to simulate/predict different geometric parameters?	#1
kaboka New Member Kaboka Join Date: Dec 2019 Posts: 18 Rep Power: 6	Hello everyone, I am working on a Diffuser's CFD model which I would like to solve with different diffuser angles and inlet velocities. However, I cannot select the diffuser angle parameter, which I had defined in DesignModeller, in DoE of 3D-ROM. I would appreciate it if anyone has any ideas or links to examples. Bests

February 16, 2022, 08:52		#2
LoGaL Senior Member Lorenzo Galieti Join Date: Mar 2018 Posts: 373 Rep Power: 12	Hi kaboka, Having back in the days tested the very early version of the ROM builder which was provided me by the developers, I can confirm you 100% that this is not possible. Different geometry = different Mesh, in particular, also different number of elements. What the ROM does is building a reduced order model (ROM) of the variables of interest for each mesh element, based on the value of such variables provided by the different solutions you use to train the model. In case the mesh changes, it is a bit weird In theory, it could be possible to obtain a ROM in a part of the domain which is not changing, provided you also, somehow, manage to obtain the same mesh there, but I do not believe it is something possible with the current release version. kaboka likes this.

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February 16, 2022, 09:18		#3
kaboka New Member Kaboka Join Date: Dec 2019 Posts: 18 Rep Power: 6	Hi Lorenzo, Thanks a lot for your answer. Now it's more clear that it's not quite possible. As I found a developer, one more question that's in my mind is the reduced-order model of transient 3D CFD simulations in ANSYS Workbench. I can easily generate a ROM model of a 3D-CFD steady-state simulation but for transient, I heard that's a bit hard in ANSYS, or do I need to buy the Twin Builder Licence for the Dynamic ROM Builder? If you had any roadmaps, that would help a lot. Bests

February 16, 2022, 12:02		#4
LoGaL Senior Member Lorenzo Galieti Join Date: Mar 2018 Posts: 373 Rep Power: 12	Bear in mind, I was no developer, I just happened to test a very early version for my company. We where interested in using it for combustion applications. Back in the days it was only possible to generate Roms for steady simulations. I am not sure if then they added the possibility to do it for unsteady runs. For time averaged flow fields of unsteady runs, it should be easy to generate Roms..... If you want instead "time resolved" Roms, I am not sure.