1332 
IV, THREE-SHOCK INTERSECTIONS 
Three-shock intersections in air are not yet 
11) 3) 
understood, although the so-called "simple" theory offers 
a first approximation for strong shocks. The requirement 
here is that the pressure be uniform between adjacent shocks. 
It can be satisfied, however, only if there is a discontinuity 
D in tangential material-velocity (and density) in one of the 
regions (cf. fig. 15). 
3) has been 
The same method 
used to survey three-shock 
configurations for water-like 
substances e 
For the limiting 
value €-1 the various condi- 
tions result in a cubic equa- 
tion for cos /3, » Vises 
M 
{4 0! coma, -ECy rr e’- ayo Lo 7" J con, - 
~2o‘now, +r “+ [lm o~'* +n) cow 3, - 
~ 2 mo’ cou sa, + (m-n)] = 0 
4 
5 
é 
B 
it 
Kyriye oh Pta( ato te? 
and nego's! {(y+l)ro! -2(y -1)0'2 -4} 
— #4 ao! 
ts Say" 
SS 
