Forced Vortex Flow in Centrifugal Pump

When a fluid enters the impeller of a centrifugal pump, the impeller rotates and imparts kinetic energy to the fluid. This kinetic energy is then converted into pressure energy as the fluid flows through the casing and exits the pump.

The flow of water leaving the impeller in a centrifugal pump casing is a forced vortex flow. This means that the fluid motion is characterized by a rotating motion around a central axis. The fluid particles are forced to rotate in a circular path by the impeller blades.

The forced vortex flow in a centrifugal pump is governed by the following principles:

1. Conservation of angular momentum: The angular momentum of the fluid remains constant as it flows through the impeller and casing. This means that the fluid particles rotate at a constant rate around the central axis.

2. Continuity equation: The mass flow rate of the fluid remains constant as it flows through the pump. This means that the velocity of the fluid decreases as it moves from the impeller to the casing.

3. Bernoulli's principle: The pressure of the fluid decreases as its velocity increases. This means that the pressure of the fluid is lowest at the impeller inlet and highest at the casing outlet.

In a forced vortex flow, the fluid particles rotate at the same angular velocity around the central axis. This means that the velocity of the fluid particles decreases as the distance from the central axis increases. The velocity of the fluid is highest at the impeller inlet and lowest at the casing outlet.

Conclusion:

In conclusion, the flow of water leaving the impeller in a centrifugal pump casing is a forced vortex flow. This type of flow is characterized by a rotating motion around a central axis. The fluid particles are forced to rotate by the impeller blades, and the flow is governed by conservation of angular momentum, continuity equation, and Bernoulli's principle.