In a horizontal channel that feeds off a river, does the head/pressure loss due to friction, turns etc in the channel translate to a drop in the water level between its inlet and outler? If so, could someone provide a basic insight how?
Thanks.
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Sign up to join this communityIn a horizontal channel that feeds off a river, does the head/pressure loss due to friction, turns etc in the channel translate to a drop in the water level between its inlet and outler? If so, could someone provide a basic insight how?
Thanks.
If the channel is horizontal, the flow will set a slope to use the head lost as a potential energy to turn it to kinetic energy that is required to overcome the head loss at the bends and also the viscosity losses.
One can guess a head loss and use it as slope and write the Manning formula for discharge and calculate the flow and from there the height of the water at exit.
If the height is more than say two feet we change our guess by reducing the height to one foot and adding the head as slope, S, recalculating. Until the results become closer and closer to our tolerance.
The flow velocity is not uniform over a cross section through the channel because of the viscosity of the water. It is zero at the walls and a maximum in the center of the free surface.
The viscous forces tend to reduce the flow velocity. The work done by the viscous forces is counterbalanced by work done by gravity, as the depth of the stream decreases and the water moves vertically down as well as flowing horizontally.