(B) sharply peaked leading edge, thick trailing edge
(C) symmetric section with large maximum thickness ratio
(D) circular arc camber line with sharp leading edge
Official Answer Key:
A
Step-by-Step Solution & Explanation
### **Detailed Step-by-Step Solution (GATE AE 2008 Q.43)**
**1. Supercritical Airfoil Design Principles (Whitcomb Airfoil)**:
Developed to delay transonic shock formation and drag divergence:
1. **Flattened Upper Surface**: Minimizes the local expansion of supersonic flow over the suction surface, reducing peak Mach number and weakening the recompression shock wave.
2. **Cambered Aft Section (Cusp / Rear Loading)**: Recovers lost lift from the flattened upper surface through substantial positive camber near the trailing edge.
**2. Official Master Key**:
- **Official Answer Key**: **A** (largely flattened upper surface, highly cambered aft section)