The discharge coefficient (Cv) is a dimensionless parameter used in fluid dynamics to quantify the efficiency of a flow control device, such as a valve, nozzle, or orifice, in allowing fluid to pass through it. It represents the ratio of the actual flow rate through the device to the theoretical flow rate based solely on the pressure drop across the device. In other words, it indicates how well the device converts the pressure energy of the fluid into kinetic energy.
Where:
- is the discharge coefficient (dimensionless)
- is the flow rate (in cubic meters per second, m³/s)
- is the pressure drop across the valve or orifice (in pascals, Pa)
This formula essentially represents the ratio of the actual flow rate to the theoretical flow rate based on the pressure drop alone