A channel step, shown in the figure below, is in a 5 m wide channel of rectangular cross-section. The total mass flowrate is 64,000 kg/s. The fluid is slurry (density 1200 kg/m3). The downstream flow depth (i.e. at section 2) is 1.5 m and the step height is 0.8 m. The bed of the channel, upstream and downstream of the step, is horizontal and smooth. The flow direction is from section 1 to section 2. Part A. Compute the following quantities: (a) Velocity of flow at section 2. (b) Froude number at section 2. (c) Specific energy at section 2.
Can you do Part C?
A channel step, shown in the figure below, is in a 5 m wide channel of rectangular cross-section. The total mass flowrate is 64,000 kg/s. The fluid is slurry (density 1200 kg/m3). The downstream flow depth (i.e. at section 2) is 1.5 m and the step height is 0.8 m. The bed of the channel, upstream and downstream of the step, is horizontal and smooth. The flow direction is from section 1 to section 2.
Part A. Compute the following quantities:
(a) Velocity of flow at section 2.
(b) Froude number at section 2.
(c) Specific energy at section 2.
(d) For the flow at section 2, where would you look for the hydraulic control?
Part B. Show all the forces acting on the control volume contained between sections 1 and 2. Show also your choice for the positive direction of distance and of force.Compute the following quantities:
(a) Specific energy at section 1.
(b) Depth of flow at section 1.
(c) Velocity of flow at section 1.
(d) Froude number at section 1.
(e) The force acting on the step.
(f) The direction of the force acting on the step i.e. upstream or downstream.
(g) The critical depth for the flow.
Part C. Sketch the free-surface profile between sections 1 and 2.
State any assumptions used for your calculations.
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