This document discusses centrifugal pumps and the work done by centrifugal pumps. It defines key terms used to describe the velocity components at the inlet and outlet of an impeller, including tangential velocity, absolute velocity, relative velocity, flow velocity, and whirl velocity. It also defines the diameters and angles involved. Formulas are presented for calculating velocity components when water enters the impeller radially. The document was prepared by an assistant professor to explain problems on centrifugal pumps.

1. Fluid Mechanics and Machinery
(CE 8394)
Panimalar Institute of Technology
Department of Mechanical Engineering
Problems on Centrifugal Pumps
Prepared by: Mr. Amos Gamaleal David
Assistant Professor
Department of Mechanical Engineering
Panimalar Institute of Technology

2. Centrifugal Pump

6. Work Done by a Centrifugal
Pump

7. At the Inlet
u1 = Tangential Velocity at Inlet
V1 = Absolute Velocity of water
Vr1 = Relative Velocity at the inlet
Vf1 = Flow Velocity at the inlet
Vw1 = Whirl Velocity at the inlet
D1 = Diameter of the impeller at inlet
α = Angle made by V1 at inlet with the direction of the
motion of the vane
θ = = Angle made by Vr1 at inlet with the direction of
the motion of the vane

8. At the Outlet
u2 = Tangential Velocity at Outlet
V2 = Absolute Velocity of water
Vr2 = Relative Velocity at the Outlet
Vf2 = Flow Velocity at the Outlet
Vw2 = Whirl Velocity at the Outlet
D2 = Diameter of the impeller at Outlet
β = Angle made by V2 at inlet with the direction of the
motion of the vane
Φ = = Angle made by Vr2 at inlet with the direction of
the motion of the vane

9. Formulae

11. If water
enters
Radially
α = 90o
Vw1 = 0
V1 = Vf1
Inlet Triangle
Outlet Triangle

12. In the Inlet Triangle
In the outlet Triangle

33. Thank You for your Patience
and Cooperation
33