BE/B Eng Bachelor of Engineering Bachelor of Aerospace Engineering 3

Question 1

In a supersonic nozzle, what determines the exit Mach number?

Accepted Answer

The ratio of exit area to throat area

Answer

For supersonic flow, the exit Mach number is uniquely determined by the area ratio (Ae/At) through the isentropic area-Mach relation.

Question 2

What is the primary advantage of a delta wing configuration for supersonic aircraft?

Accepted Answer

Reduced wave drag and improved supersonic stability

Answer

The highly swept delta wing generates leading-edge vortices and has a thinner effective cross-section relative to freestream flow, reducing wave drag at supersonic speeds.

Question 3

Which parameter is conserved along a streamline in inviscid, adiabatic flow according to Bernoulli's equation for compressible flow?

Accepted Answer

Total (stagnation) enthalpy

Answer

For inviscid adiabatic flow, total enthalpy h0 = h + V²/2 is constant along a streamline, which generalizes Bernoulli's equation to compressible flows.

Question 4

What is the function of a reaction control system (RCS) on a spacecraft?

Accepted Answer

To control attitude and perform small translational maneuvers in space

Answer

The RCS uses small thrusters (often hypergolic) to control spacecraft orientation and make fine translational adjustments where aerodynamic surfaces are ineffective.

Question 5

In fatigue analysis of aerospace structures, what does the stress ratio R represent?

Accepted Answer

Ratio of minimum stress to maximum stress in a cycle

Answer

R = σ_min/σ_max defines the loading character: R = -1 is fully reversed, R = 0 is pulsating tension, and R = 1 is static.

BE/B Eng Bachelor of Engineering Practice Test

BE/B Eng Bachelor of Engineering Practice Test

BE/B Eng Bachelor of Engineering Bachelor of Aerospace Engineering 3