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shock front. Eq. 5.2 provides a relation that is convenient for this pur- 
pose. Although the shock-front conditions should properly be calculated 
from the Ranking-Hugoniot relations, Eq. 2.2, the small value of the entropy 
change at the shock front makes it possible to assume an adiabatic change. 
Since the pressure bo of the undisturbed fluid can be neglected compared 
to the parameter B » we note that 
2 
B = Pole /n, (5.3) 
where (2 is the density and C, the velocity of sound in the undisturbed 
fluid. Using Eq. 5.2, we find the following important relations, 
2 n 
= i, = (| 
p= 2? IG) 
-1)/2 (n-i\Wan 
= ()” . 0, (1+ ab, ) ! 
(e foe (5.4) 
(n-U/2Z Co "tae in| 
Oras ad nafs Se (i+ 2.) S 
where i is the pressure, C sound velocity, and ¢. sound velocity at zero 
pressure. The enthalpy q), equal to il ado » With neglect of dissipation 
is 
Heil & 
yr (Ceo + - om, (5.5) 
Moreover, if the Riemann function S is small at the shock front, the wave 
front velocity UV is related to & in the following manner, 
