[Shah Akib Sarwar]

Hello,

I am currently trying to solve a problem using Star-CCM+ that involves gas exiting a nozzle at high velocity and hitting the ground. The aim is to find the temp/pressure values on the point where the gas hits the ground (stagnation point). The Mach number at nozzle exit is 5. However, beyond Mach 3, the solver runs into convergence issues due to temperature anomalies (temperature exceeds the maximum allowable value of 5000K). I am using steady, coupled flow, coupled energy, k-omega-SST models for the solution. As I am fairly new to CFD and Star-CCM+, any suggestions on how to solve this issue would be greatly appreciated.

Also, if there is any analytical way to scale the results I got for Mach 3 to Mach 5 (even if it is a rough estimate), that would be of great help too!

Thank you.

[Peresvet]

Originally Posted by Shah Akib Sarwar

Hello,

I am currently trying to solve a problem using Star-CCM+ that involves gas exiting a nozzle at high velocity and hitting the ground.

Thank you.

If the program could easily cope with such tasks, then hypersonic weapons would not only be ours. Moreover, you are just learning. In such tasks, the designer should be more cunning than cfd.
To be honest, inside the current generator you can decide anything, but not what came out of the supersonic nozzle at GREAT Mach numbers. You can only adjust the solution to the practical result, and this is a secret program.
Sorry.