Hydraulic coefficient

Orifice -: orifice is a smaller opening of the side or at bottom of a tank . Mouthpiece is a short length of pipe is 2-3 times of it's dia-meter in length fitted in a tank of vessel con- taining the fluid. 

The various types of hydraulic coefficient 

1. Coefficient of velocity -: The ratio of the velocity of the jet at vena-contracta to the theoretical velocity is known as coefficient of velocity. In the terms of coordinates ( a,b) for vena-contracta, Cv = a / √4bH .

H = Height of fluid in the tank.

The average value of  coefficient of velocity is 0.97.

2. Coefficient of discharge -: coefficient of discharge iss the ratio of the actual discharge through or orifice to theoretical discharge. 

0.62 is the average value of the coefficient of discharge. 

3. Coefficient of resistance -: The coefficient of resistance is treated equal to zero for all the practical purpose. The ratio of the loss of head in the orifice to the head of water available at the orifice exist is known as the coefficient of resistance. 

4. Coefficient of contraction-:Coefficient of contraction is the ratio of the area of the jet at vena-contracta to the area of the orifice opening. The average value of the coefficient of contraction is 0.64 .