Please help me! I'm not able to set the gas properties in StarCD; I found only cv but not cp or R (cp-cv) or Gamma (cp/cv) Thanks in advance for your reply

R is the gas constant, so this will not change. Actually, if the gas is incompressible (density is constant), Cv is used. If the gas is compressible, assuming the ideal gas law, you only need to define Cp. Cv and Gamma are then calculated internally (Cv=Cp-R and Gamma=Cp/(Cp-R)).

Hope this dissipates your doubts...