Page 263 - 48Fundamentals of Compressible Fluid Mechanics

13.4. SOLUTION OF MACH ANGLE 225

single case that this topic used in a real world calculations. In fact, after expressed
analytical solution is provided, devoted time, seems to come on the count of many
important topics. However, this author admits that as long there are instructors
who examine their students on this issue, it should be covered in this book.
For small deflection angle, c , and small normal upstream Mach number,
,

(13.52)

... under construction.
13.4.7 Close and Far Views of The Oblique Shock

In many cases, the close proximity view provides continuous turning of the
deflection angle, c . Yet, the far view shows a sharp transition. The tradi-
tional approach to reconcile these two views, is by suggesting that the far view
shock is a collection of many small weak shocks (see Figure 13.11). At the
local view close to wall the oblique shock is a weak “weak oblique” shock.
From the far view the oblique shock is
accumulations of many small (or again
weak) “weak shocks.” However, there
small “shocks” are built or accumulate
into a large and abrupt change (shock).
In this theory, the Boundary Layer (B.L.)
q
doesn’t enter into the calculation. In re-
ality, the B.L. increases the zone where
continuous flow exist. The B.L. reduces
d
the upstream flow velocity and therefore
the shock doesn’t exist close proximity
to the wall. In larger distance form the
Fig. 13.11: Two different views from local and
the wall, the shock starts to be possible.
far on the oblique shock
13.4.8 Maximum value of of Oblique shock

The maximum values are summarized in the following Table .

Table 13.1: Table of Maximum values of the obliques Shock

c

4
4

),+
9 9
)0+
")
"
) "-9-919
"
"-9