Page 130 - 48Fundamentals of Compressible Fluid Mechanics

92 CHAPTER 5. NORMAL SHOCK

shock is still. Thus it is the case of shock moving into still medium (suddenly open
valve case). First the Mach velocity ahead the shock has to calculated.

!

Utilizing POTTO-GDC or that Table (5.4) one can obtain the following table

%(

# #

3

Using the above table, the temperature behind the shock is

3'
3
*

3

In same can be done for the pressure ratio as following %

3

#

The velocity behind the shock wave is obtain by utilizing the mass balance as

#

*

*

Example 5.3:
# # # 1
. The static
pressure at the tube is and (static) temperature of

. The gas is brought

%!(

!(/% )(

into complete stop by a sudden by closing a value. Calculate the velocity and the
Gas flows at supersonic velocity in a tube with velocity of !
1
pressure behind the reflecting shock. The specific heat ratio can be assumed to
.

SOLUTION
be
3 . Then, the prime properties can be found. At this stage the reflecting shock
The first thing which is needed to be done is to find the prime Mach number
velocity is unknown.

Simply using the Potto-GDC provides for the temperature and velocity the
following table:

)(

0(

Or if you insist on doing the steps yourself find the upstream prime Mach,
0(

'3 3
. If this
detail is not sufficient enough that simply utilize the iteration procedure described

!
to be 1.2961. Then using the Table (5.2) you can find the the proper

earlier and obtain