Centrifugal pump design and analysis

A Centrifugal pump is created and analysis is done to study the various parameters.

The dimensions of the pump are as follows.

• The diameter of the Volute casing is 90 mm.
• The thickness of the Volute casing is 15 mm.
• Rotary blade diameter is from 40mm to 80mm.
• A number of blades=5.
• The diameter of the inlet suction cylinder is 30 mm.
• Length of the inlet suction cylinder is 70 mm.
• The diameter of the delivery pipe is 12 mm.
• Length of the delivery pipe is 88 mm.
• The shell of thickness 1mm is made.
• Water is considered as working fluid.
• Surface roughness is taken as zero.
• Gravity is not considered.
• Internal type of simulation is taken.
• The rotational feature is considered in this analysis.

Boundary conditions

• Inlet suction pipe is maintained at environmental pressure [101325 Pa].
• The outlet discharge pipe is maintained at some velocity 10 [m/s].
• A domain or cylindrical structure is made around the rotor which completely covers the rotor from all the sides.
• The dimensions of the domain, diameter 85mm and thickness 12mm.
• A rotational feature which was considered for analysis is given to this domain.
• The rotational speed of this domain is 1000 rad/sec.

A parametric study is done considering the input parameters such as Velocity normal to the face taking 5 values between 10m/s to 50m/s. They are 10, 20, 30, 40, 50m/s respectively. Input parameters such as cut plots are also considered. Output parameters obtained are Total pressure at inlet and outlet and mass flow rate.

The table is shown as follows.

Mass flow rate increases as the outlet velocity increases. Here in the graph, it is shown negative because its the outlet port. So, we consider the inverse of it that is mass flow rate increases, it means the mass flow rate increases. As the outlet velocity increases pressure ratio decreases. Pressure ratio is the ratio between the outlet pressure and the inlet pressure. When the flow rate at the outlet is high the pressure reduces at the outlet which results in the decrease in the pressure ratio.

Pressure ratio plot w.r.t design points are shown below.

Mass flow rate w.r.t Design points

Total pressure at the outlet

Total pressure at the inlet

Pressure ratio vs Mass flow rate

Here in this graph, we have considered the magnitude of the mass flow rate. The mass flow rate increases with a decrease in Pressure ratio as the outlet velocity increases.

Velocity variation plot for various values of outlet Velocity obtained from the Parametric Study

Velocity variations inside the centrifugal pump as seen from the front sectional view for the velocity at the outlet 10m/s.

For outlet velocity 15m/s

For outlet velocity 20m/s

For outlet velocity 25m/s

For outlet velocity 30m/s

These are the plots obtained for 100 iterations. From the above plots, we can see that as the velocity normal to the face increases the pressure ratio decreases and the mass flow rate increases in its magnitude.

The flow trajectory is as follows

Simulation runs for 300 iterations