# Find depth of water flow in Rectangular channel

Water is flowing in a rectangular channel whose width is 5m. The depth of flow is 2m and the discharge is 25m3/sec. Determine:

(a) Depth of flow at a point downstream where the width of the channel increases to 5.5 m

(b) Depth of flow at a point downstream where the width of the channel decreases to 4.75 m

(c) At what width will this channel become choked?

(d) Describe the impact on the flow profile if the channel becomes narrower than the width found in part (c) above

https://brainmass.com/engineering/transport-engineering/find-depth-water-flow-rectangular-channel-560548

#### Solution Preview

Width of channel, w1 = 5m

Depth of flow, h1 = 2 m

discharge, Q = 25 m^3/s

Gravitational acceleration, g = 9.8 m/s^2

Area of cross-section, A = h.w

Continuity:

Q = A.v

=> v1 = Q/A1 = Q/(h1.w1) = 25/(2*5) = 2.5 m/s

Energy,

E = h + v^2/(2.g) = h + (Q/A)^2/(2.g) = h + Q^2/(2.g.A^2)= h + Q^2/(2.g.h^2.w^2)

=> E = h1 + ...

#### Solution Summary

Water flow through a rectangular channel - width of choking is estimated.