Jet propulsion and ram effect: Overall compression due to ram pressure recovery increases roughly with the square of flight speed (dynamic pressure scales with V^2), enhancing inlet total pressure.

Introduction / Context:
Air-breathing jet engines benefit from flight speed through ram pressure recovery in the inlet. The relationship between speed and the available dynamic pressure informs inlet design and engine performance at various Mach numbers.

Given Data / Assumptions:

• Subsonic to transonic flight where diffuser design provides pressure recovery.
• Dynamic pressure q = 0.5 * rho * V^2.
• Compressor itself produces its own pressure ratio, but inlet ram recovery adds to compressor face total pressure.

Concept / Approach:
Dynamic pressure scales with the square of speed. A well-designed inlet diffuser converts part of this kinetic energy into static pressure, increasing total pressure at the compressor face relative to static ambient. Thus, the contribution from ram effect to overall compression grows with V^2, though practical limits arise from losses, shocks, and inlet distortion at higher Mach numbers.

Step-by-Step Solution:

Verification / Alternative check:
Performance charts show increasing compressor face total pressure with increasing flight speed up to design Mach, consistent with ram pressure rise proportional to V^2, adjusted for recovery efficiency.

Why Other Options Are Wrong:

• Incorrect: Neglects fundamental dynamic pressure scaling.
• Correct only for propeller aircraft: Ram effect applies to jet inlets as well.
• Linear with speed: Physically incorrect because kinetic energy and dynamic pressure scale with V^2.

Common Pitfalls:
Confusing compressor pressure ratio (largely speed and geometry dependent) with ram recovery effect due to forward speed. Both contribute but are distinct.

Final Answer:
Correct