Page 275 - 48Fundamentals of Compressible Fluid Mechanics
P. 275
13.4. SOLUTION OF MACH ANGLE 237
3
stream line
2
1
θ
M 1 = 4
δ
9 . Compute the pressure ratio and temperature ratio after the second shock
(sometimes it referred as the reflective shock while the first shock is called as the
Assume that upstream Mach number is 4 and the deflection angle is c
incidental shock).
SOLUTION
This kind problem is essentially two wedges placed in a certain geometry. It is
clear that the flow must be parallel to the wall. For the first shock, the upstream
Mach number is known with deflection angle. Utilizing the table or POTTO–GDC,
the following can be obtained.
c 7 8
4
4
4
) + "
-9 91 -9
1
+ 9
" "
9
And the additional information is by using minimal information ratio button in
7 8
POTTO–GDC
c 7 5 7 8
4
4
7 8
1
)
With Mach number of " " ) + " 9 ),"- -9 7
" " the second deflection angle is also 9 . with
these values the following can be obtained.
5
c 7 8
4
4
4
9 1+)
"
" "
and the additional information is ), 9 7 8
)0 9 c +1+-"-9 7 7
5
4
4
7 8
5
7 8
"
9-),+
" "
