403 
Feces: Bist ? /p , 
where E is the internal energy per gram of fluid. We shall denote by WwW) 
(3.3) 
the enthalpy increment 
tay =: lal > (3h) 
where He is the enthalpy of the undisturbed fluid in front of the shock 
wave. The fundamental thermodynamic equation for H yields 
dw > TdaS+ap/p, (3.5) 
where T is the absolute temperature. The enthalpy increment 4) may be 
written in the form, 
(hae : 
W = el Sa T (pS) 45" 
} p(S p) . (3.6) 
where Pg and Sy are the pressure and entropy of the undisturbed fluid, and 
the line integrals are on paths of constant entropy, S, and pressure, p,, 
respectively. Introduction of Eq. 3.5 into Eq. 3.1 with the use of Eq. 3.2 
yields 
Gris pat Sh yD ee ) Dies O 
eet C00 Dt 
oe ux(yxu)e - VATS, (3.7) 
where (Y may be called the kinetic enthalpy and c is the velocity of sound 
in the fluid in state (p,S). Numerical calculations based upon the equation 
17 
