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Mechanical Engineering · Q229

Compressors, Gas Turbines And Jet Engines

Engineering and GATE · Mechanical Engineering · question 229

Q229

If V, U and Vr represent the absolute velocity of fluid, velocity of blade, and relative velocity of fluid, and suffix ‘I’ and ‘o’ stand for entry and exit conditions, then in a rotary machine whose degree of reaction is unity

A.
Vi = Vo
Answer
B.
Vt > Vo
C.
U < Vo
D.
V = Uo

Answer: Option A

Solution

Answer: Option A
Solution:
If V, U and Vr represent the absolute velocity of fluid, velocity of blade, and relative velocity of fluid, and suffix ‘I’ and ‘o’ stand for entry and exit conditions, then in a rotary machine whose degree of reaction is unity Vi = Vo