Density Based or Pressure Based?
 

Hello,

I am trying to model the exhaust of a Merlin rocket engine at various altitudes. I have been following a tutorial of methane air combustion ( https://cfd.ninja/ansys-fluent/ansys...us-combustion/ ) but have altered it to suit my needs. I have obtained a list of exhaust products using NASA's CEA run software and have input those mass fractions into the exhaust products inlet boundary condition. The velocity of the exhaust products inlet is 3090m/s and the velocity of the air inlet is 300m/s.

I am wondering whether I need to use a pressure based solver or a density based solver for this as they both return very different results.

Thanks