An orifice meter, having an orifice of diameter ‘d’ is fitted in a pipe of diameter D. For this orifice meter, what is the coefficient of discharge Cd?

An orifice meter, having an orifice of diameter ‘d’ is fitted in a pipe of diameter D. For this orifice meter, what is the coefficient of discharge Cd? Correct Answer A function of d/D and Reynolds number

An orifice meter provides a simpler and cheaper arrangement for the measurement of flow through a pipe. An orifice meter is essentially a thin circular plate with a sharp-edged concentric circular hole in it.

Important Points

The coefficient of discharge shows as the losses inflow. Since in laminar flow losses are less and in turbulent losses is more hence the value of the coefficient of discharge also varies with the type of flow. As we know Reynold number shows the type of flow occurring hence we can say that the coefficient of discharge also depends upon the Reynold number.

Related Questions

The discharge through a small rectangular orifice is given by (where Cd = Coefficient of discharge for the orifice, a = Cross-sectional area of the orifice, h = Height of the liquid above the centre of the orifice)
The discharge through a large rectangular orifice is given by (where H1 = Height of the liquid above the top of the orifice, H2 = Height of the liquid above the bottom of the orifice, b = Breadth of the orifice and Cd = Coefficient of discharge)