i could not find the actual flow profile of a spillway .In theoritical/practical the downstream height of flow is less than the height of the dam. but in my case after running the problem, i am getting the height of the downstream water is at the level of the inlet height. That is i am getting the result as a submerged dam. it is showing the value of velocity above the dam height in the downstream side of dam.

My understanding of water flowing over dams is that the differnce between water level behind the dam and the lower level in the spillway is basically due to friction and the fact that there needs to be a positive pressure (higher level of water) to move the water down the spillway.

The problems outlined sound to be like the friction has not been turned on, or the pressure required for the water to leave the 'outlet' is too high. Leading to the building up of water above the dam.

I think that it is likely that the boundary conditions for the water flow into the model and the water flow out of the model space seems a bit out.

Hope this helps.

Leon

[luccy]

hi
it's my first time using fluent to simulate a flow.i want to model the flow over a stepped spillway.in my model ,flow does not start over spillway and does not fall over steps and stay in one point.i dont know what is wrong.
can anyone help me?