CFD Online Discussion Forums

CFD Online Discussion Forums (
-   FLUENT (
-   -   velocity contour ( March 9, 2013 14:18

velocity contour
1 Attachment(s)
Hi guys,
i have a semi circular shaped open channel. I had setting up fluent, but it is not giving proper contour profile. It is giving closed contour loops. What is the mistake i have done, can anybody tell because contour lines for it don't have closed loops.
Here i am attaching the profile which i got.
Kindly comment and help me.:confused::confused::confused:

flotus1 March 9, 2013 15:03

What kind of open channel flow reaches 5000 m/s? Are you sure that there is no mistake in your setup?

How did you specify the "open" boundary? March 11, 2013 04:07

I don't know about what kind of channel reaches a speed of 5000 m/s.
Simply i selected a channel having semi circular cross section.
While giving boundary conditions:
for inlet-
mixture- flow in z direction
top water surface level= 0
bottom water surface level= -2
radius of semi circular channel= 2
flow rate of water= (wetted area)*(Velocity of water)*(density of water)
remaining as default conditions

oj.bulmer March 11, 2013 15:58

There is something seriously wrong here. Your water is reaching velocities 6 times higher than bullet!!! Check the boundary conditions

OJ March 15, 2013 10:08

you are right Mr. bulmer, i did mistake in dimensions. But still i got the closed contours for semi circular channel. I have some doubt regarding modelling. I did the modelling and gave body as fluid in place of solid. In meshing, i gave the named selection to its sides as walls. I doubt that there is something wrong in meshing. Can anyone tell me where i am doing the mistake? Semi circular channel doesn't have all its contours closed.............:confused::confused::confused:

oj.bulmer March 15, 2013 10:53

Can you attach a snap of how you specified boundary conditions? Have you specified the upper surface as free surface/free slip wall?

OJ March 16, 2013 06:02

i defined top surface of semi circular channel as a free surface.
At inlet i defined it as mass flow inet.
Outlet as outflow.
remaining as default conditions March 16, 2013 09:36

I have one regarding the open channel flow that should there be any interface between air and water, if yes, how we shall do the modelling and proceed?
One thing also how we define the section plane in meshing?

flotus1 March 16, 2013 11:38

I suggest you have a look at least at the fluent manual before you simulate multiphase flow. March 16, 2013 15:32

Can you mail me fluent manual at
I don't have that manual.

oj.bulmer March 17, 2013 09:40

Here it is:

Although, since you can access FLUENT, I believe the Help documentation must be installed on your PC.


All times are GMT -4. The time now is 20:38.