Question

The Prandtl–Glauert rule gives the relation between

• A. viscous and inviscid flow
• B. compressible and incompressible flow
• C. supersonic and subsonic flow
• D. transonic and subsonic flow

Hint:

Used primarily to adjust lift and pressure coefficients in subsonic compressible flows.

Answer 1

The Correct Option is B

The Prandtl–Glauert rule is a fundamental concept in aerodynamics, particularly within the field of aerospace engineering. It establishes a relationship between compressible and incompressible flow conditions.

In aerodynamics, the behavior of air as a fluid can be analyzed under different flow conditions. An incompressible flow assumes that the density of the fluid remains constant, which is a valid approximation at low speeds. However, as speeds increase and approach the speed of sound, compressible effects need to be considered due to changes in density.

The Prandtl–Glauert rule provides a correction factor that relates the aerodynamic characteristics (like lift and drag) of an object in a compressible flow to those in an incompressible flow. This correction is crucial for increasing accuracy in calculations and predictions.

In summary, the Prandtl–Glauert rule connects:
Compressible and Incompressible Flow