School of Engineering AERO2481: Aircraft Performance Assignment

This document provides comprehensive solutions to an Aircraft Performance assignment, addressing key concepts in aerospace engineering. The assignment encompasses calculations for thrust required at different altitudes and velocities for the Beechcraft Queen Air, maximum velocity graphs, and drag calculations. It also includes analysis of the Fairchild Republic A-10, involving power and velocity calculations at sea level and altitude. Further questions explore wind tunnel experiments, moment coefficient determination, and the impact of horizontal tails on aircraft stability. The assignment also covers finite wing analysis, lift-to-drag ratio calculations, and skin friction drag estimation, providing a thorough examination of aircraft performance metrics.

Question 1
Consider an airplane modelled after the twin-engine Beechcraft Queen Air executive
transport.
The airplane has the following characteristics: weight is 38,220 N; wing area is 27.3 m2;
aspect ratio is 7.5; Oswald efficiency factor is 0.9; and zero-lift drag coefficient CD,0 is 0.03.
1.a. Calculate the thrust required to fly at a velocity of 725 km/h at standard sea level.
Assume the value of ρ∞ = 1.225 kg/m3 at standard sea level. (Round the final answer to the
nearest whole number.)

1.b. Calculate the thrust required to fly with a velocity of 675 km/h at an altitude of 4.5 km.
Assumethe value of ρ∞ = 0.777 kg/m3at an altitude of 4.5 km. (Round the final answer to
the nearest whole
number.)
1.c Calculate and graph the maximum velocity of the Beechcraft Queen Air with respect to
altitude.Construct the graph between seal level and a maximum altitude of 20,000 ft.

Question 2
2. An airplane weighing 5,000 lb is flying at standard sea level with a velocity of 700 mi/h.
At this velocity, the L/D ratio is a maximum. The wing area and aspect ratio are 200 ft2
and 8.5, respectively. The Oswald efficiency factor is 0.93. Calculate the total drag on the
airplane. Assumeρ∞ = 0.002377 slug/ft3. (Round the final answer to one decimal place.)

Question 3
Consider an airplane modelled after the Fairchild Republic A-10, a twin-jet attack aircraft.
The airplane has the following characteristics: wing area = 47 m2; aspect ratio = 6.5;
Oswald efficiency factor = 0.87; weight = 103,047 N; and zero-lift drag coefficient = 0.032.
The airplane is equipped with two jet engines, each with 40,298 N of static thrust at sea
level. Assume the velocity of the
airplane is 160 m/s.
3.a. Calculate the power required at sea level. (Round the final answer to the nearest whole
number. Answer this part of the question before moving on to the next part.)

3.b. Calculate the maximum velocity at sea level. (Round the final answer to the nearest
whole number. Answer this part of the question before moving on to the next part.)
3.c. Calculate the velocity, Valt, power, Palt, required at 5 km altitude. Assume ρ at 5 km
altitude =0.7364 kg/m3. (Round the final answers to the nearest whole number. Answer this
part of the question before moving on to the next part.)

3.d. Calculate the maximum velocity at 5 km altitude. Assume ρ at 5 km altitude = 0.7364
kg/m3. (Round the final answer to the nearest whole number.)
Question 4
Consider a model of a wing–body shape mounted in a wind tunnel. The flow conditions in
the test section are standard sea-level properties with a velocity of 140 m/s. The wing area
and chord are1.5 m2 and 0.45 m, respectively. Using the wind tunnel force and moment-
measuring balance, the moment about the center of gravity when the lift is zero is found to
be −12.4N.m. When the model is pitched to another angle of attack, the lift and moment
about the center of gravity are measured to be 3675 N and 20.67N.m, respectively.
Calculate the value of the moment coefficient about the aerodynamic center and the
location of the aerodynamic center. (Round the final answers to three
decimal places.)