Learning Forum

[jfe293]

Hi,

I was trying to simulate a rectangular open channel flume from a thesis. I ran the simulation succesfully and my velocity and turbulencce profiles were close to the thesis data. But one crucial issue is that I was not able to establish a zero pressure gradient condition. My professor is asking me to determine the flow rate that creates zero pressure gradient in the developed region, so that the flow is entirely driven by gravity. My boundary conditions are given below:

Inlet: Mass Flow Inlet

Outlet: Pressure outlet
Free Surface: Symmetry

Bottom surface and side wall: Wall

I have set the gravitational accelartion componets in the following way:

gx=g*Bed Slope

gy=0

gz= - 9.81

I will very much appreciate if I could get some proper guidance from this forum on fixing this issue.

Thanks.

[Rob]

With zero pressure drop won't there be zero flow? For an open channel flume I'd use the VOF open channel options. They sidestep the hydrostatic fun related to pressure gradients and operating density.