Average Velocity from Velocity Profile

AI Thread Summary
To calculate average velocity from velocity profiles at different lateral positions in a channel, the mean of the discrete velocity points can be used if they are evenly spaced. For unevenly spaced points, a weighted average may be necessary. The average velocity can also be determined by the change in position over time if the starting and ending times are known. The discussion highlights the need for clarity regarding the attachment with point velocities at various depths and lateral positions. Understanding the cross-section's dimensions, including wall locations, is crucial for accurate calculations.
Rupayan0504041
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Hi
I have velocity profiles at different lateral position of a channel. I want to calculate average velocity from velocity profile at those position. Can you suggest me any equation or literature?
I attached here a sample datasheet also.
 

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If you just have a bunch of discrete points, why not just take the mean?
 
these are the discrete points at different depth so it will make logarithmic V profile so for maximum and mean which equation should I follow? Is it just mean of this discrete points?
 
If they are evenly spaced, then the mean velocity is just the mean of the points. If they aren't evenly spaced you may need to do a weighted average.
 
If you can calculate a formula based on the discrete points, you could find the average velocity. This could be an issue, as you could create a high degree polynomial that would go through all the points, but that may not be an accurate representation of velocity versus position between the discrete points.

If you knew the starting time and the ending time for the discrete positions, then the average velocity would just be the change in position / change in time.
 
It's a measurement of ADV in laboratory flume. I have point velocity at different depth and different width of a cross section. So how can I calculate average velocity in this cross section? If you go through the attachment, it will be clear to you. Also I have the discharge value for this setup laboratory run.
 
Rupayan0504041 said:
It's a measurement of ADV in laboratory flume. I have point velocity at different depth and different width of a cross section. So how can I calculate average velocity in this cross section? If you go through the attachment, it will be clear to you. Also I have the discharge value for this setup laboratory run.
I went through the attachment, and it wasn't clear to me.
 
Chestermiller said:
I went through the attachment, and it wasn't clear to me.
Can you just tell me which part isn't clear in attachment?
 
I have point velocity at different depth and different lateral position in a laboratory channel cross section. And I need to calculate average velocity of that cross section and also average depth velocity at different lateral position.
 
  • #10
Rupayan0504041 said:
I have point velocity at different depth and different lateral position in a laboratory channel cross section. And I need to calculate average velocity of that cross section and also average depth velocity at different lateral position.
What are the locations of the walls?
 
  • #11
Chestermiller said:
What are the locations of the walls?
Left wall is at y=0 and right one is y=10
 
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