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Hello, some questions about Lagrangian method (I use Star-CCM):

1.) What is the best way to know that my solution is good enough? I tried monitoring a report that calculates the average velocity of my disperse phase however it was not expressive at all but only fluctuating strongly (roughly between 0 and 100 m/s, surrounding speed of continous phase ~100m/s). I was simulating 4000 Iterations and created a plot that portrayed the average velocity of the particles over the iteration step.
I thought about checking mass flow values for given parts but I'd like to understand the above mentioned behavior.

2.) I have one-way coupling and a completed simulation, now I read somewhere that if thats the case I only need to do one more Iteration since all the Langrangian sub steps are made between the iterations and my main flow is already converged. When I did this the solution itself did not look "bad" but I was suspicious because the time took like 2 minutes. Have I understood this wrong?

Thanks a lot!