Engineering Equations:
Thermodynamics, enthalpy
h = enthalpy, Btu/lb
P = absolute pressure, psia
U = internal energy, Btu/lb
v = specific volume, ft3/lb
h = U + 0.185 P v
Thermodynamics, isobaric process: entropy change
Cp = specific heat, constant pressure, Btu/lb/°F
T = absolute temperature, °R
s = entropy, Btu/lb/°R
s2 - s1 = Cp*ln(T2/T1)
Thermodynamics, polytropic process, entropy change
Cv = specific heat at constant volume, Btu/lb/°F
k = adiabatic exponent for gas
n = polytropic constant for gas
s = entropy, Btu/lb/°R
T = absolute temperature, °R
s2 - s1 = Cv*((n-k)/(n-1))*ln(T2/T1)



