Reconsider Prob. 662. For the specified flow rate, investigate the effect of discharge angle 2 on

Reconsider Prob. 6–62. For the specified flow rate, investigate the effect of discharge angle α₂ on the minimum power input requirements. Assume the air to enter the impeller in the radial direction (α₁ = 0°), and vary α₂ from 0° to 85° in increments of 5°. Plot the variation of power input versus α₂, and discuss your results.

Data from Problem 62

Consider a centrifugal blower that has a radius of 20 cm and a blade width of 8.2 cm at the impeller inlet, and a radius of 45 cm and a blade width of 5.6 cm at the outlet. The blower delivers air at a rate of 0.70 m³/s at a rotational speed of 700 rpm. Assuming the air to enter the impeller in the radial direction and to exit at an angle of 50° from the radial direction, determine the minimum power consumption of the blower. Take the density of air to be 1.25 kg/m³.

FIGURE P6–62

Transcribed Image Text:

1 1 I I 12 W Impeller region α₂ = 50° V₂ 1 I