Page 155 - 48Fundamentals of Compressible Fluid Mechanics

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Equation (7.7) can be rearranged as
7.1. ISENTROPIC NOZZLE (
(7.8)

and is the nozzle length

Equation (7.10) dimensionless form by utilizing

(7.9)

!
!

And the final form of equation (7.10) is #

(7.10)

The term

%)

for “standard” situations. The dimensionless number, sometimes referred as

is considered to be very small (

Ozer number determines whether gravity should be considered in the calculations.
Nevertheless, one should be aware of value of Ozer number for large magnetic

#
fields (astronomy) and low temperature, In such cases, the gravity effect can be

considerable.

As it was shown before the transition must occur when
. Conse-
quently, two zones must be treated separately. First, here the Mach number is
(the sub-
is positive and the treads determined by gravity and
discussed and not the pressure as in the previous chapter. For
the area function.

or conversely,
sonic branch) the term

is negative and

therefore (the supersonic branch) the term

For the case of

is indeterminate. As it was shown in chapter ??

, is zero either

, the denominator

For the border case

) only when

And the

the flow is chocked (
(7.11)

or