Aeroplane Aerodynamics

Question 1

What contributes to the total aeroplane drag

Answer 1

• Pressure & skin friction drag on wings
• Pressure & skin friction drag on tail, fuselage, engines, landing gear
• Induced drag (mostly on wings)
• Interference drag

Question 2

Eq for vstall

Answer 2

vstall = sqrt(2L/ρSCLmax)

Question 3

Drag Eq in terms of CL & CD

Answer 3

D = L/(CL/CD)

Question 4

Graph of D vs V∞

Answer 4

3 lines drawn
1 - Induced Drag, starts high on the LH side and reduces as a curve close to zero on the RH side
2 - Parasite Drag, starts at origin and increases as a shallow parabola crossing the Induced drag line
3 - Total Drag, starts off similarly to the induced drag, reaches a minimum where lines 1 & 2 cross then increases following the parasite drag curve

Question 5

Eq for PR (Power required)

Answer 5

PR = v∞ * D
Following that and substituting Eq for drag
PR = sqrt((2(nW)^3)/ρS) * 1/(CL^3/2 / CD)