Skip to main content

Fluid Mechanics · Integral mass, momentum, and energy balances

A vertical pipe of interior diameter D = 100 mm discharges water (ρ = 998 kg/m³)…

Problem

A vertical pipe of interior diameter D = 100 mm discharges water (ρ = 998 kg/m³) downward to the atmosphere through an open end. The discharge speed is V = 8.0 m/s, uniform across the exit. A control volume is drawn from an upstream flange (section 1), where the pipe is still full and the gage pressure is p_1 = 25 kPa, down to the free exit (section 2), which is 1.20 m below section 1. The contained water volume between the two sections is the interior volume of a right circular cylinder of diameter D and length 1.20 m. Take +x horizontally (unused) and +y vertically upward, so the exit velocity is in the −y direction and gravity is in the −y direction, g = 9.81 m/s². The pipe is stationary. Define F_y as the vertical force that the upper flange and any hangers apply to the pipe-and-water control volume, positive in the +y direction (tension in hangers is therefore positive). Include the weight of the contained water; omit the metal weight. The exit is at atmospheric pressure. Neglect interior shear. Determine F_y.

Hint

Constant diameter and a full pipe mean the y-momentum flux does not change between flange and exit.

Check your work

Work the problem yourself first. Then open it in Training to check your answer and read the full worked solution.

The answer check and full solution for this problem come with ProofAnvil Practice membership ($19 USD monthly). See membership. Or start with the free Fluid Mechanics sample problem: Try the free sample problem.

More Fluid Mechanics practice problems

Back to Fluid Mechanics

An original ProofAnvil practice problem, written for this course. ProofAnvil is a practice course, not a homework-answer service.