• Sections 11.4-11.12 of Anderson.
• Sections 12.1-12.2 of Anderson.

Problems from Anderson
11.4
11.5
11.6
11.7

Study Questions

1. What is the definition of the critical Mach number?
    
2. Why is the critical Mach number of interest?
    
3. Will the critical Mach number increase or decrease as the lift produced by the airfoil increases?
    
4. Will the critical Mach number increase or decrease as the airfoil thickness increases?
    
5. What is meant by the drag-divergence Mach number?
    
6. List two factors that contribute to the rapid increase in drag around Mach 1.
    
7. Typically by what factor does the drag increase as an aircraft passes through Mach 1?
    
8. What is meant by the ``sound barrier''? Does it really exist? Explain your answer.
    
9. State the area rule for transonic flow.
    
10. Does the area rule require a widening or thinning of the fuselage in the vicinity of the wing? Explain your answer.
     
11. By what factor can the peak drag near Mach 1 be reduced through use of the area rule?
     
12. What is a supercritical airfoil?
     
13. What is the advantage of a supercritical airfoil?
     
14. Why does the supercritical airfoil have a concave region on the lower surface near the trailing edge?
     
15. How will the quarter chord pitching moment coefficient for a supercritical airfoil compare with a conventional airfoil?