Setting Time-Step Size to Match Motions
When simulating motions, the time-step size should be matched to the mesh movement.
For this tutorial, to resolve the fluid in the small gaps during rotation, the time step-size is chosen to match one degree of rotation. When complex physics is involved, for example multiphase, the time step should be reduced further.
In this tutorial, the configurations of the two rotors are listed as follows:
Rotor | Number of Teeth | Geometry Sector | Rotation Rate | Time Period | Time Steps/ Geometry Sector | Time Step Size |
---|---|---|---|---|---|---|
Outer Rotor | 12 | 30° | 1000 rpm | 0.005s | 30 (to match 1 degree of outer rotor's rotation) | 1/6000 s
You use a fraction to improve the rotational precision. |
Inner Rotor | 11 | 32.73° | 1090.90909 rpm | 0.005s | 30 | 1/6000 s |
You resolve one cycle with 30 time steps, which corresponds to 1° rotation of the outer rotor.
Select the Time-Step to 1/6000 s.
node and set