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why my simulation does not stabilize?

Hi everyone,

I have done two simulations of a vehicle wheel which is rotating at 42.9 rad/s and the ground is also moving. The air speed is 15m/s. Analyzing the force curves with hypergraph I do not understand why my simulations do not stabilize at some value and continue to oscillate.

Can anybody help me?

Thank you

Results of the simulations:

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HyperMesh CFD

v2021.0

Accepted answers

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acupro

This could be mesh related - but most likely this is a transient flowfield, not steady-state, so there will some variation in the results. If you're happy with the steady-state approach, you could use the average value, say from time 3.0E+11 (time step 30). You can also try decreasing the Steady Update Factor in the Solver Controls. But most likely this is a transient flow.

Marc Campi

I will try a new simulation with the new mesh.

In the flow and "physics" section the selected parameters are for steady flow, I don't understand where the transient flow comes from.

Thank you so much.

acupro

I will try a new simulation with the new mesh.

In the flow and "physics" section the selected parameters are for steady flow, I don't understand where the transient flow comes from.

Thank you so much.

The time steps in Steady are the 'outer loop' iterations. It's something like pseudo time steps, since the default time step size is very large 1E10, and the time integration is first order.

When running Transient, we would define a more physical time step size, and the time integration is second order.