Learning Forum

[amdifut]

Good Afternoon,

I am currently working in LS-PrePost and I am trying to create a pulsatile, sinusoidal inlet velocity for a 2D geometry simulation. The inlet velocity expression is 0.0266*0.00786*sin(2*3.14*0.3*TIME). For the inlet velocity, I have inserted via the keyword *DEFINE_CURVE_FUNCTION as shown in the image, however I am receiving an error.

What are the steps to correcly apply this pulsatile sinusoidal function to the inlet?

[Reno Genest]

Hello Andy,

What you are doing seems correct to apply a pulsating inlet velocity with the ICFD solver in LS-DYNA. You are using the *ICFD_BOUNDARY_PRESCRIBED_VEL keyword and specifying the pulsating inlet velocity using a load curve with *DEFINE_CURVE_FUNCTION. Also, *ICFD_BOUNDARY_PRESCRIBED_VEL is  applied to part 1 which is the inlet.

The warning message is about the *ICFD_MAT ID=1 card. Could you post a screenshot of *ICFD_MAT  ID=1 in your model? Are load curves ID 1701669236 and 41 refered to in *ICFD_MAT ID=1? Do you have these load curves defined in your model with the *DEFINE_CURVE keyword?

 

Also, what happens if you run this model with the LS-DYNA solver? Do you get an error message? If so, what is it?

 

Reno.

 

[amdifut]

Hi Reno,

I ended up resloving the issue by using LS-Prepost on another server. I am not sure what excatly was causing the issue, but I replicated my steps in another server and it worked without getting any errors. However, I was missing a Point ID for selecting angular velocity within the ICFD_BOUNDRY_PRESCRIBED_VEL. 

To answer your question, before creating the POINT ID, When I ran the model in LS-RUN, it would run for a about 15 seconds then it would terminate. Once I looked into the message file, I notice the termnination was caused by a missing POINT ID. I have attatched my ICFD_MAT ID for your reference. 

 

Thank you for replying back to me. 

[Reno Genest]

Hello Andy,

Maybe the version of LS-PrePost you are using on the different computers are different.

It seems you are all set for now. If you don't have further questions, I will close this topic.

 

Have a great day!

 

Reno.