Measuring of water level and mean velocity
 

How to calculate the actual water level,mean velocity and the discharge in open channel in the region of high turbulence as hydraulic jump.
i can measure other regions water level by isosurface at w.v.f. Equal 0.5 , water velocity using expression areaavg(water superficial velocity)@isoclip.
When I used the same method in the interested region,it gave me wrong value.

Can you show some images of what you are doing and why the result is wrong?

Also you can use functions like areaInt(volume fraction)@cross section plane to get the wet area of a cross section, and you should be able to get the surface height from that.

Thank you sir,
There's the velocity vectors for some sections ,
Attachment 58118Attachment 58119Attachment 58120
The problem in vector 3 that is the one that gave me the wrong values .i think that is due to the reverse flow in this section as shown in the picture,But I don't know how to deal with it.

The attachments did no t work. Have a look at the FAQ: https://www.cfd-online.com/Wiki/Ansy...n_the_forum.3F

I have no idea what those images are showing or what it means. You are going to have to explain what is going on.

I'm trying to model a free surface,multi phase (water,air) open channel flow with an obstacle across the channel section. Attachment 58165

Referring to that image, which information do you need CFD to tell you?

Measuring of water level and mean velocity
 

Water level,velocity and discharge in the shown region.