The nozzle of a ventilation duct is placed 9.5 m above the floor of the hydraulic laboratory and it is directed vertically downward.
The outlet discharges 2,300 m3/hour.
(a) For a circular duct, calculate the diameter of the nozzle if the maximum permissible velocity at a height of 1.5 m above the floor is 0.95 m/s?
(b) An alternative design uses a wide rectangular duct (10 m long), calculate the opening of the nozzle if the maximum permissible velocity at a height of 1.5 m above the floor is (b1) 0.95 m/s and (b2) 0.50 m/s? Discuss your results.
Assume a quasi-two-dimensional flow pattern.
The fluid is air at 28 Celsius and standard pressure.