Question

1. consider the isentropic flow of air through a duct whose area is decreasing. find the percentage changes in velocity, density and pressure induced by 2% reduction in area for mach number m-0.1; m

Answer 1

In an isentropic flow of air through a duct with decreasing area, you can calculate the percentage changes in velocity, density, and pressure based on the Mach number and the change in area. Use the isentropic flow relations to find these percentage changes.

Step-by-step explanation:

In an isentropic flow of air through a duct with decreasing area, the percentage changes in velocity, density, and pressure can be calculated based on the Mach number and the change in area. The Mach number (M) is defined as the ratio of the flow velocity to the speed of sound. We can use the isentropic flow relations to find the following percentage changes:

1. Percentage change in velocity (ΔV/V): This can be calculated using the equation ΔV/V = (γ - 1) / 2 * ΔA/A, where γ is the ratio of specific heats and ΔA/A is the percentage change in area.
2. Percentage change in density (Δρ/ρ): This can be calculated using the equation Δρ/ρ = -γ / (γ - 1) * ΔA/A.
3. Percentage change in pressure (ΔP/P): This can be calculated using the equation ΔP/P = -2γ / (γ - 1) * ΔA/A.

Substituting the given values, such as the Mach number being 0.1 and the 2% reduction in area, into these equations will allow you to calculate the desired percentage changes.