Open Channel Flow Practice Questions

In a rectangular channel, the ratio of the velocity head to the flow depth for critical flow condition, is

A rectangular open channel has a width of 5 m and a bed slope of 0.001. For a uniform flow of depth 2 m, the velocity is 2 m/s. The Manning's roughness coefficient for the channel is

Variation of water depth(y) in a gradually varied open channel flow is given by the first order differential equation $\frac{\mathrm{d} y}{\mathrm{d} x}=\frac{1-e^{-\frac{10}{3}\ln(y)} }{250-45e^{-3\ln(y)}}$ Given initial condition: y(x=0)=0.8 m. The depth (in m, up to three decimal places) of flow at a downstream section at x = 1 m from one calculation step of Single Step Euler Method is ______

A 5 m wide rectangular channel, the velocity u distribution in the vertical direction y is given by $u=1.25y^{\frac{1}{6}}$ . The distance y is measured from the channel bed. If the flow depth is 2 m, the discharge per unit width of the channel is

A 10 m wide rectangular channel carries a discharge of 20 $m^{3}/s$ under critical condition. Using g = 9.81 $m/s^{2}$ , the specific energy (in m, up to two decimal places) is ______

For a given discharge in an open channel, there are two depths which have the same specific energy. These two depths are known as

A 1 m wide rectangular channel carries a discharge of 2 $m^{3}/s$ . The specific energy-depth diagram is prepared for the channel. It is observed in this diagram that corresponding to a particular specific energy; the subcritical depth is twice the supercritical depth. The subcritical depth (in meters, up to two decimal places) is equal to _____

A sluice gate used to control the flow in a horizontal channel of unit width is shown in the figure. It is observed that the depth of flow is 1.0 m upstream of the gate, while the depth is 0.2 m downstream of the gate. Assuming a smooth flow transition across the sluice gate, i.e., without any energy loss, and the acceleration due to gravity as 10 $m/s^{2}$ the discharge (in $m^{3}/ s$ , up to two decimal places) passing under the sluice gate is_____

A 1 m wide rectangular channel has a bed slope of 0.0016 and the Manning's roughness coefficient is 0.04. Uniform flow takes place in the channel at a flow depth of 0.5 m. At a particular section, gradually varied flow (GVF) is observed and the flow depth is measured as 0.6 m. The GVF profile at that section is classified as

A 4 m wide rectangular channel, having bed slope of 0.001 carries a discharge of $16\:\, m^{3}/s$ . Considering Manning's roughness coefficient = 0.012 and $g =10\: \: m/s^{2}$ , the category of the channel slope is

A 3m wide rectangular channel carries a flow of $6\: m^{3}/s$ . The depth of flow at a section P is 0.5 m. A flat-topped hump is to be placed at the downstream of the section P. Assume negligible energy loss between section P and hump, and consider g as $9.81\: m/s^{2}$ . The maximum height of the hump (expressed in m) which will not change the depth of flow at section P is ____________

The pre-jump Froude Number for a particular flow in a horizontal rectangular channel is 10. The ratio of sequent depths (i.e., post-jump depth to pre-jump depth) is ___________

A hydraulically efficient trapezoidal channel section has a uniform flow depth of 2m. The bed width (expressed in m) of the channel is __________ .

A short reach of a 2 m wide rectangular open channel has its bed level rising in the direction of flow at a slope of 1 in 10000. It carries a discharge of 4 $m^{3}/s$ and its Manning's roughness coefficient is 0.01. The flow in this reach is gradually varying. At a certain section in this reach, the depth of flow was measured as 0.5 m. The rate of change of the water depth with distance, dy/dx, at this section is ____ (use g = 10 $m/s^{2}$ ).

A hydraulic jump is formed in a 2 m wide rectangular channel which is horizontal and frictionless. The post-jump depth and velocity are 0.8 m and 1 $m/s$ , respectively. The pre-jump velocity is _______ $m/s$ (use g=10 $m/s^{2}$ ).

A hydraulic jump takes place in a frictionless rectangular channel. The pre-jump depth is $y_{p}$ . The alternate and sequent depths corresponding toalternate and sequent depths corresponding to $y_{p}$ are $y_{a}$ and $y_{s}$ respectively. The correct relationship among $y_{p},y_{a}$ and $y_{s}$ is:

A rectangular channel of 2.5 m width is carrying a discharge of 4 $m^3$ /s. Considering that acceleration due to gravity as 9.81 m/ $s^2$ , the velocity of flow (in m/s) corresponding to the critical depth (at which the specific energy is minimum) is _______

A rectangular channel having a bed slope of 0.0001, width 3.0 m and Manning's coefficient 'n' 0.015, carries a discharge of 1.0 $m^3/s$ . Given that the normal depth of flow ranges between 0.76 m and 0.8 m. The minimum width of a throat (in m) that is possible at a given section, while ensuring that the prevailing normal depth is not exceeded along the reach upstream of the contraction, is approximately equal to (assume negligible losses)