Loss of Energy due to Sudden Contraction

                                                          (6)

where is the coefficient of contraction. The value of is not constant but

depends on the ratio . In general, the loss of head due to sudden contraction is taken to be equal to i.e. the value of k is adopted as 0.5.

Loss of Energy at the Entrance to a Pipe

Energy loss at the entrance to the pipe is also called as 'inlet loss'. It occurs, when the liquid enters to the pipe from a large vessel (or tank). The flow pattern is similar to that of sudden contraction. In general, for a sharp-cornered entrance, the loss of head at the entrance is taken equal to , where V is the mean velocity of flow of liquid in the pipe.