SimScale CAE Forum

Difference between adjustable time step: True and False - Transient Analysis Results

LINK OF THE PROJECT: https://www.simscale.com/workbench/?pid=622516419259523012&rru=62147762-37bf-469c-b8d0-3a4c36b748b5&ci=d75b993c-945d-4518-ae07-9b2d3aa035ae&ct=CONVERGENCE_PLOT&mt=SIMULATION_RESULT

Actual simulation: Compressible 9

SUMMARY: I’m simulating a transient analysis about an Intake manifold for an internal combustion engine, It has a turbocharger so the mass flow parameter it’s high, I established the pressure pulse in excel with the RPM but my issues are:

  1. I made an adjustable time step false run, and seems like every peak of pressure ( the pressure pulse per cylinder) corresponds in an increment in the courant mean number. But I don´t now if the fluctations in the parameters suits with the analysis phenoma.

Transient test 51:

  1. I made an adjustable time step true run, with a max courant number of ten, but also the other parameters fluctuate but it’s slower than false, less pressures pulses I have to work to allow more pulses.

Transient test 56:

Also I worked with a standard mesh but It’s uniform and coarse, because in previous tests diverged with hex parametric. Forum: Courant Number, Mesh, relaxation factors and schemes issues - #5 by agredafuentes1

So, I need help to interpret the results, and how to make it better. Thanks. I will apreciate it.

Hi there, thank you for using the forum!

I am tagging the @power_users to provide some insight

Best regards,
Fillia

Hi, I’ll be waiting for and answer :slight_smile: