How to speed up Radioss computation?

Allen Lai_22108

Hi all,

I'm doing bicycle brake frictional heat test. Test scenario is a bicycle has constant 12.5 km/hr velocity continued 120 second. In the same time, brake pad press on the brake drum. We want to know during the time the brake drum displacement & temperature. Unit system is "mm kg ms GPa".  I also use solver keyword "-mpi -np 4 " but computation time still need a lot of time. Please someone help me to correct this case.

Thanks!

Adriano_Koga

Allen Lai_22108 said:

Thank you sir. It's really helpful to me. I had use AMS card to enforce my model timestep and Parith/off card to speed up my computation. AMS card parameter is Tscale 0.9 and Tmin 50 times natural  timesteps. In this case, what timestep set up are you recommend?

i don't know what else can be done here, as your analysis is really long, indeed.

50x increase in timestep looks a lot already.

Check the added mass, anyway.

 

Adriano_Koga

There is a similar example supplied with the Help for Radioss. It might be helpful, maybe.

 

I'm not Radioss expert, but you could try to accelerate your run by enforcing a fixed timestep, maybe, using the DT/CST solver card inside the engine cards. Trying maybe to enforce a 1e-04 timestep.

Be careful with the added mass (DM/M), in order to keep the model realistic, specially as there's lots of rotation here.

 

Allen Lai_22108

Thank you sir. It's really helpful to me. I had use AMS card to enforce my model timestep and Parith/off card to speed up my computation. AMS card parameter is Tscale 0.9 and Tmin 50 times natural  timesteps. In this case, what timestep set up are you recommend?

Adriano_Koga

Allen Lai_22108 said:

Thank you sir. It's really helpful to me. I had use AMS card to enforce my model timestep and Parith/off card to speed up my computation. AMS card parameter is Tscale 0.9 and Tmin 50 times natural  timesteps. In this case, what timestep set up are you recommend?

i don't know what else can be done here, as your analysis is really long, indeed.

50x increase in timestep looks a lot already.

Check the added mass, anyway.

 

Allen Lai_22108

Adriano A. Koga_21884 said:

i don't know what else can be done here, as your analysis is really long, indeed.

50x increase in timestep looks a lot already.

Check the added mass, anyway.

 

Thanks sir. You did a big favor !