Question

Why cd value is high in venturi meter than orifice meter?

Answer 1

In Venturi meter losses are less so coefficient of discharge is higher whereas in orifice meter due to no convergent and divergent cones there are more losses and hence its coefficient of discharge is less.In venturi meter losses are low due to steamline shape of the diffuser and the pressure gradient is not abrupt as in case of orifice meter.

Answer 2

Answer:

In Venturi meter losses are less so coefficient of discharge is higher whereas in orifice meter due to no convergent and divergent cones there are more losses and hence its coefficient of discharge is low.

Step-by-step explanation:

• When using the orifice meter, the orifice  area suddenly contracts. As you know, with each sudden contraction or expansion, boundary layer separation occurs and the formation of large eddies significantly reduces the pressure of the liquid. These eddies consume much of the mechanical energy of the liquid.
• Venturi meter throat area gradually decreases. Therefore, there is no eddies formation. This additional pressure drop in the aperture counter due to the formation of eddies is the reason why Cd is relatively low.
• Coefficient of discharge : It is the ratio of actual flow rate to ideal flow rate. It is always less than one.