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2nd YEAR FLUIDS / COMPRESSIBLE FLOW

THUS SOLVING FOR M :

(3.20)

- FOR = 1.4, EQUATION (3.20) SUGGESTS THAT GAS FLOW WOULD BECOME COMPRESSIBLE WHEN :

M > 0.3

STAGNATION CONDITIONS ARE FREQUENTLY REFERRED TO AS RESERVOIR CONDITIONS.

- GIVEN

THE RESERVOIR CONDITIONS & THE BACK PRESSURE P_B,

THE EXIT MACH NUMBER Me AND FLOW RATE CAN BE DETERMINED.

CRITICAL VALUES

- A FLOW IS CRITICAL WHEN IT IS SONIC, M = 1.

- THE CRITICAL CONDITIONS ARE DENOTED BY ' * ' AND ARE OBTAINED BY SETTING M=1 IN THE MACH NUMBER RELATIONS (3.16) TO (3.19).