5484

A high-speed air turbine cascade is estimated to have an AVDR of 0.97. At inlet the Mach number is 0.22 and the flow angle is 30°. The blades turn the flow through 100° and at exit the flow is just sonic. Take ? to be 1.4.

a. Determine the stagnation pressure loss coefficient based on exit conditions and the energy loss coefficient, ?.

b. Estimate ? using the Soderberg correlation for this cascade, Eq. (3.46), assuming an aspect ratio of 3. Compare with the value found in (a) and explain why the correlation might be expected to underestimate the loss in this case.

c. Neglecting