Compressible flow and shock waves MCQs – Aerospace

1. Compressible flow occurs when:
(A) The fluid density changes significantly with pressure
(B) The fluid density remains constant
(C) The fluid velocity is below the speed of sound
(D) The flow is steady and uniform

2. A shock wave is characterized by:
(A) A sudden change in fluid properties such as pressure, temperature, and density
(B) Gradual changes in fluid properties
(C) Constant fluid properties across the wave
(D) No change in fluid velocity

3. In compressible flow, the Mach number represents:
(A) The ratio of the flow velocity to the speed of sound
(B) The ratio of pressure to density
(C) The temperature gradient in the flow
(D) The Reynolds number

4. A Mach number greater than 1 indicates:
(A) Subsonic flow
(B) Sonic flow
(C) Supersonic flow
(D) Hypersonic flow

5. The normal shock wave occurs when:
(A) The flow is accelerating
(B) The flow is decelerating
(C) The flow passes through a region of supersonic speed to subsonic speed
(D) The flow is incompressible

6. In supersonic flow, the area of a nozzle must:
(A) Decrease to accelerate the flow
(B) Increase to accelerate the flow
(C) Remain constant
(D) Be equal to the critical area

7. The Prandtl-Meyer function is used to:
(A) Determine the changes in flow properties across a shock wave
(B) Calculate the expansion of supersonic flow in a divergent nozzle
(C) Estimate the drag coefficient in compressible flow
(D) Predict the boundary layer behavior

8. The area-Mach number relationship in a converging-diverging nozzle shows that:
(A) The flow accelerates through the converging section and decelerates through the diverging section
(B) The flow decelerates through both sections
(C) The flow accelerates through both sections
(D) The flow remains constant through both sections

9. The shock wave angle in a shock wave is related to:
(A) The Mach number of the flow and the wedge angle
(B) The temperature of the fluid
(C) The viscosity of the fluid
(D) The density of the fluid

10. In compressible flow, the Mach number at the throat of a converging-diverging nozzle is:
(A) Less than 1
(B) Equal to 1
(C) Greater than 1
(D) Zero