GATE_AE_2027_MOCK_02_Q20
GATE 2027 Aerospace Engineering All-India Master Mock 02 (Compressible Aerodynamics & High-Speed Propulsion)
MCQ · 1 Mark
Aerodynamics & Fluid Mechanics • Wind Tunnel Testing & Instrumentation • Wind Tunnel Boundary Corrections & Hot Wire
In a subsonic closed-throat wind tunnel, the presence of solid boundary walls causes the streamlines around an airfoil model to be constrained. This blockage effect results in an apparent measured freestream velocity that is:
(A) Higher than the actual undisturbed freestream velocity
(B) Lower than the actual undisturbed freestream velocity
(C) Completely unaffected by the model cross-section
(D) Zero along the test section centerline
Answer Key:
A
Step-by-Step Verified Solution
### Solution: Solid blockage constrains flow around the model, squeezing streamtubes and causing flow acceleration near the model, making the apparent local velocity higher than in free air. Correct: A.