Home | Engineering | Applied Hydraulic Engineering - CE6403 | Critical , Sub-critical and super critical flow

civil - Applied Hydraulic Engineering: Rapidly Varied Flow

Critical , Sub-critical and super critical flow

   Posted On :  13.07.2016 04:49 pm
Critical , Sub-critical and super critical flow

The specific energy change with depth was plotted above for a constant discharge Q, it is also possible to plot a graph with the specific energy fixed and see how Q changes with depth.

Rapidly Varied Flow

Critical , Sub-critical and super critical flow

 

The specific energy change with depth was plotted above for a constant discharge Q, it is also possible to plot a graph with the specific energy fixed and see how Q changes with depth. These two forms are plotted side by side below.


From these graphs we can identify several important features of rapidly varied flow.

 

For a fixed discharge:

 

1.   The specific energy is a minimum, E sc , at depth y c , This depth is known as critical depth .

 

2.      For all other values of E s there are two possible depths. These are called alternate depths. For

 

subcritical  flow y > yc

 

supercritical  flow y < yc

 

For a fixed Specific energy

 

1. The discharge is a maximum at critical depth, yc

 

2. For all other discharges there are two possible depths of flow for a particular Es

 

i.e. There is a sub-critical depth and a super-critical depth with the same Es

 

An equation for critical depth can be obtained by setting the differential of E  to zero:

 

 




Tags : civil - Applied Hydraulic Engineering: Rapidly Varied Flow
Last 30 days 83 views

​ReadOrRefer.in

OTHER SUGEST TOPIC