RP-1 flows steadily through the \(90^{\circ}\) reducing elbow shown in the illustration. The absolute pressure at the inlet to the elbow is \(107.3 \mathrm{kPa}\) and the cross-sectional area is \(0.01 \mathrm{~m}^{2}\). The cross-sectional area at the outlet is \(0.0025 \mathrm{~m}^{2}\) and the velocity there is \(16 \mathrm{~m} / \mathrm{s}\). The elbow discharges to the atmosphere. Find the velocity of the propellant entering the elbow and the force required to hold the elbow in place. Assume that the outside pressure is \(101 \mathrm{kPa}\), the density of RP- 1 is constant at \(810 \mathrm{~kg} / \mathrm{m}^{3}\), that the volume of the elbow is 11 , and that gravity points in the \(-z\) direction. Neglect the weight of the elbow itself.

Transcribed Image Text:

A = 0.01 m P = 220 kPa 1 x A = 0.0025 m P2 = 101 kPa