[USAMAMAJEED]

If I use average depth velocity then obviously it will be less velocity and length of jump will be very small. Can I use velocity in lower region of stilling basin instead of depth average velocity to have better match with physical model. Velocity in green region below blue region is much higher than upper region. I have attached screenshot below:
Thanks in advance

[MSM1985]

Depth average velocity are faster in deep area and shallower in lower areas. Check both velocities: Depth averaged velocity and horizontal velocity component. Whichever gives close approximation to physical model observation, use that velocity component.

[USAMAMAJEED]

Originally Posted by msm1985

depth average velocity are faster in deep area and shallower in lower areas. Check both velocities: Depth averaged velocity and horizontal velocity component. Whichever gives close approximation to physical model observation, use that velocity component.

thanks very much. If i use maximum velocity along length of region it give close results to physical model or i use horizontal component which will be negstive due to formation of rollers st the start of jump.

[MSM1985]

-ve velocity is due to reverse eddies/rollers in the hydraulic jump due to turbulence. If you need the velocity entering into the jump, use velocity before this turbulence region and that region might be at chute of the spillway. You can use either depth average velocity or horizontal velocity component, whichever is close to physical modeling.