Circular Channel Ratios

[owillis28]

In what situation are you allowed to use the circular channel ratios. I am really shaky using this chart. If someone has any insight or an example problem detailing the importance (or why you use this), I would appreciate it.

 

[Guest]

In what situation are you allowed to use the circular channel ratios. I am really shaky using this chart. If someone has any insight or an example problem detailing the importance (or why you use this), I would appreciate it.

owillis --

You can use the circular channel ratios for gravity flow of water in a pipe - they are especially useful for culverts and sewer pipes. Remember the utility of these charts is to be able to 'quickly' solve a problem like:

1. Given full flowing pipe, what is the depth (D) of water in the pipe if the flow is cut by 1/2; or

2. Given a full flowing pipe, what is the reduction of flow (Q) if the flow drops to 0.4D.

This allows for a 'quick' ratio multiplication problem instead of having to resolve the manning equation for different geometrical constraints.

Hope this helps.

JR