Bachelor of Aerospace Engineering Flashcards
7 cards from real BE/B Eng Bachelor of Engineering practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Bachelor of Aerospace Engineering flashcards as text
In a supersonic nozzle, what determines the exit Mach number?
Answer: The ratio of exit area to throat area
For supersonic flow, the exit Mach number is uniquely determined by the area ratio (Ae/At) through the isentropic area-Mach relation.
What is the primary advantage of a delta wing configuration for supersonic aircraft?
Answer: Reduced wave drag and improved supersonic stability
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.
Which parameter is conserved along a streamline in inviscid, adiabatic flow according to Bernoulli's equation for compressible flow?
Answer: Total (stagnation) enthalpy
For inviscid adiabatic flow, total enthalpy h0 = h + V²/2 is constant along a streamline, which generalizes Bernoulli's equation to compressible flows.
What is the function of a reaction control system (RCS) on a spacecraft?
Answer: To control attitude and perform small translational maneuvers in space
The RCS uses small thrusters (often hypergolic) to control spacecraft orientation and make fine translational adjustments where aerodynamic surfaces are ineffective.
In fatigue analysis of aerospace structures, what does the stress ratio R represent?
Answer: Ratio of minimum stress to maximum stress in a cycle
R = σ_min/σ_max defines the loading character: R = -1 is fully reversed, R = 0 is pulsating tension, and R = 1 is static.
Which effect causes an aircraft to experience a nose-up pitching moment when flaps are deployed?
Answer: Increased camber moves the center of pressure aft relative to the center of gravity
Flap deployment increases camber and shifts the additional lift aft, moving the overall center of pressure behind the CG and creating a nose-down pitching moment (not nose-up); if this is reversed, it indicates CG is aft of the new lift center.
What is the primary function of a phase-locked loop (PLL) in spacecraft communication systems?
Answer: To synchronize a local oscillator to the incoming carrier frequency
A PLL tracks and locks onto the incoming carrier's phase and frequency, enabling coherent demodulation of the signal even with Doppler shifts.