Page 293 - 48Fundamentals of Compressible Fluid Mechanics

14.7. EXAMPLES U K P Q KJ K U U 255

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Note that

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The “new” width can be calculated from the mass conservation equation.

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Note that the compression “fan” stream lines are note and their function can be
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obtain either by numerical method of going over small angle increments. The other
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alternative is using the exact solution . The expansion “fan” angle change in the

Mach angle between the two sides of the bend

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Reverse example, this time the pressure is given on both sides and angle is

fan angle
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needed to be found .
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Gas with flows over bend (see Figure 14.2 ) . Compute the Mach number
after the bend, and the bend angle.
Example 14.2:U J
SOLUTION
The Mach number is determined by satisfying the condition that the pressure down
steam are Mach the given one. The relative pressure downstream can be calcu-
lated by the relationship

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2 Not really different from this explanation but shown in more mathematical form, due to Landau and

friends. It will be presented in the future version. It isn’t present now because the low priority to this
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issue present for a text book on this subject.
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3 This example is for academic understanding. There is very little with practical problems.