Determine the energy loss that will occur if water flows from a reservoir into a pipe with a velocity of $3~\m/\s$ if the configuration at the entrance is (a) an inward-projecting pipe, (b) a square-edged inlet, (c) a chamfered inlet, or (d) a well-rounded inlet.

The loss that occurs is given as $$ h_L=K\left(\frac{v^2}{2g}\right) $$ The velocity head in this example is $$ \left(\frac{v^2}{2g}\right) = \left(\frac{3~\m/\s}{2(9.81~\m/\s^2}\right)=0.456~\m $$ and the energy loss simplified as $$ h_L=K\times 0.456~\m $$ The resistance coefficients are given in the section on entrance losses.

For (a) an inward-projecting pipe we have $K=0.78$: $$ h_L=0.78\times 0.456~\m = 0.358~\m $$ For (b) a square-edged inlet we have $K=0.5$: $$ h_L=0.5\times 0.456~\m = 0.229~\m $$ For (c) a chamfered inlet we have $K=0.25$: $$ h_L=0.25\times 0.456~\m = 0.115~\m $$ For (d) a well-rounded inlet we have $K=0.04$: $$ h_L=0.25\times 0.456~\m = 0.018~\m $$