Probelem I: Air (assumed frictionless and incompressible, ( 7.64x10^-2 lb/ft^3 )

Question

Probelem I:          Air (assumed frictionless and incompressible, ( 7.64x10^-2 lb/ft^3) flows steadily through the device shown. The exit velocity is 100 ft/sec and the differential pressure across the nozzle is 6 lb/ft^2. Determine:

1.     The reading, H, for the water-filled manometer (62.4 lb/ft^3 attached to the Pitot tube.

2.     Determine the diameter, d, of the nozzle.

Air (assumed frictionless and incompressible, ( 7.64x10^-2 lb/ft^3) flows steadily through the device shown. The exit velocity is 100 ft/sec and the differential pressure across the nozzle is 6 lb/ft^2. Determine: The reading, H, for the water-filled manometer (62.4 lb/ft^3 attached to the Pitot tube. Determine the diameter, d, of the nozzle.

Explanation / Answer

1) 1/2 rho*V^2 = rho*g*H              H = V^2/2g = 100^2/(2*32.18) = 155.35ft 2) at exit, velocity = 100ft/s and diameter = 0.1ft applying continuity equation at exit and at starting pi/4 (0.15^2) * v1 = pi/4 (0.1^2)*100 v1 = 44.44 ft/s the decrease in pressure energy across the nozzle is converted into kinetic energy 1/2 rho*v^2 = (del)P 0.5 * 62.4*v^2 = 6 v = 0.44 ft/s change in velocity across the nozle = 0.44 ft/s therefore velocity at the exit of nozzle, v2 = 44.44+0.44 = 44.88 ft/s applying continuity equation, pi/4 0.15^2 * v1 = pi/4 d^2 *v2 0.15^2 * 44.44 = d^2 * 44.88 d = 0.149 ft

Related Questions

Navigate

• Browse (All)
• Browse P
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.