Reynolds number and its significance in aerospace MCQs – Aerospace

1. Reynolds number is a dimensionless quantity that characterizes:
(A) The flow speed of a fluid
(B) The relative importance of inertial and viscous forces in a fluid flow
(C) The temperature of the fluid
(D) The density of the fluid

2. The Reynolds number is defined as:
(A) The ratio of inertial forces to gravitational forces
(B) The ratio of viscous forces to inertial forces
(C) The ratio of inertial forces to viscous forces
(D) The ratio of gravitational forces to inertial forces

3. In aerospace applications, Reynolds number is important for:
(A) Determining the aerodynamic efficiency of an aircraft
(B) Calculating fuel consumption
(C) Measuring engine thrust
(D) Estimating the temperature of the engine

4. A high Reynolds number typically indicates:
(A) Dominance of viscous forces over inertial forces
(B) Dominance of inertial forces over viscous forces
(C) Low flow speed
(D) Low turbulence

5. Incompressible flow is generally assumed when the Reynolds number is:
(A) Low
(B) High
(C) Zero
(D) Negative

6. The Reynolds number is used to predict:
(A) The temperature distribution in a fluid
(B) The flow regime (laminar or turbulent)
(C) The chemical reaction rate
(D) The heat transfer coefficient

7. The transition from laminar to turbulent flow occurs at a Reynolds number typically around:
(A) 500
(B) 1,000
(C) 2,300
(D) 10,000

8. For a given flow, increasing the Reynolds number generally leads to:
(A) A decrease in flow turbulence
(B) A decrease in flow speed
(C) An increase in flow turbulence
(D) A decrease in viscous effects

9. In aerospace testing, Reynolds number similarity is crucial for:
(A) Scaling wind tunnel results to real flight conditions
(B) Measuring fuel efficiency
(C) Determining the weight of the aircraft
(D) Calculating the thrust-to-weight ratio

10. Reynolds number is calculated using:
(A) Fluid density, velocity, and dynamic viscosity
(B) Fluid density, velocity, and specific heat
(C) Fluid velocity, temperature, and pressure
(D) Fluid viscosity, temperature, and density