Time step independence in Transient simulation with RPI Wall boiling
 

I am trying to simulate subcooled flow boiling in horizontal channel with Non-equilibrium RPI wall boiling model. It is transient simulation with Implicit scheme. Steady state simulation are not giving the true results so that scenario is already discarded. I have already performed grid independency and now trying to do time step converging/independence for transient simulation. Started with time step of 5E-02 and reduced upto 1E-05. But, the results keep changing every time. The results have shown to match when time step is around 5E-03. With smaller time step, The results keep changing significantly.

y+ is around 30. I am using ANSYS Fluent

So, please help me how time step independence can be achieved?

The models and schemes are listed in picture attached.

Dear MarcusAurelius,
Do you have some figures to introduce ? Is it changing a lot when decreasing your time step ?


Best regards,
Pierre

I have found out the reason for that. Selecting interfacial area model "ia-symmetric" instead of "ia-particle" solved the problem of Time step convergence.

But, the results are now way different than expected. The wall temperature is increasing by 2-3 times than actual.