Question

The ratio of axial velocity to peripheral speed of the blades is

• A. flow coefficient
• B. loading coefficient
• C. rotor enthalpy loss coefficient
• D. rotor pressure loss coefficient

Hint:

Flow coefficient determines the operating point of compressors and turbines.

Answer 1

The Correct Option is A

In the context of aerospace engineering, specifically when dealing with rotating machinery such as compressors or turbines, a fundamental concept involves understanding the relationship between various flow parameters and their impact on performance. The axial velocity and the peripheral speed of the blades are two critical parameters.

The axial velocity (V_a) refers to the speed at which the fluid travels in the direction parallel to the axis of the rotor, whereas the peripheral speed (U) is the speed of the rotor blades along the circumference.

The flow coefficient (φ) is a dimensionless number that describes the ratio of the axial velocity of the flow through the machine to the peripheral speed of the rotor blades. Mathematically, it is defined as:

φ = V_a / U

This coefficient helps in determining the operating condition of the rotor, indicating the efficiency of the flow relative to the speed of the blades. Among the options provided, the ratio of axial velocity to peripheral speed of the blades is best described by the flow coefficient.