Assumptions for compressible flow Adiabatic flow with negligible heat transfer Reversible process with fluid isentropic flow friction being neglected Perfect gas P=pRT Internal energy u and enthalpy h: u=C,th=cpt Specific heat ration: k=C/C C,EREX kR R k-1 k-19 Assumptions for compressible flow Internal energy u and enthalpy h: u = Cv T h = Cp T •Adiabatic flow with negligible heat transfer •Reversible process with fluid friction being neglected isentropic flow •Perfect gas p = RTCp Cv Specific heat ration: k = / Cp −Cv = R −1 = k kR Cp −1 = k R Cv