[shaoyikai813]

Hello everyone,
I am doing inlet port design as my uni project with star ccm+. I am having problems now but my supervisor is away.


First of all I am planning to simulat two engine speed, 4500rpm and 14500rpm.
There is not a option of velocity outlet. How can I simulate different engine speed? Currently, I am having pressure outlet with negtaive number which makes outlet avg velocity around the piston mean velocity at that engine speed. Is it right way to do?

Secondly, I have mesh error when I use corse mesh such as 3mm base mesh. As picture shows below:


It is fine if I use fine mesh like 1mm. It getting worse as base mesh getting bigger. I created the geometry in Solidoworks and input into ccm with STEP file.

The last is the simulations are not converging with any of mesh size. The polt of outlet mass flow showing wave.

The model I used:





Thank you in advance.