Eleven equally spaced turning vanes are used in the horizontal plane 90° bend as indicat...

Eleven equally spaced turning vanes are used in the horizontal plane 90° bend as indicated in Fig. P5.19R. The depth of the rectangular crosssectional bend remains constant at 3 in. The velocity distributions upstream and downstream of the vanes may be considered uniform. The loss in available energy across the vanes is The required velocity and pressure downstream of the vanes, section (2), are 180 ft_s and 15 psia. What is the average magnitude of the force exerted by the air flow on each vane? Assume that the force of the air on the duct walls is equivalent to the force of the air on one vane.