Can the pressure-based solver be used in a high Mach number flow?
Pressure based solver can be used for high speed flows up to 2-3 Mach number. It becomes fragile once Mach number is pushed above 4. The main issue is with the energy equation, which is decoupled from the system and solved in a segregated manner. For hypersonic flows, it is advised to use density based solver which is fully coupled.