Validation Case: Centrifugal Pump Curve Multi-purpose

This validation case belongs to fluid dynamics and aims to validate the following parameters of a centrifugal pump. The SimScale Multi-purpose solver was used to generate these results.

Pressure drop [\(Pa\)]
Power [\(W\)]

The results of SimScale are compared with the results of the study by WANG Xiu-yong and WANG Can-xing entitled “Performance Prediction of Centrifugal Pump Based on the Method of Numerical Simulation.”\(^1\).

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Geometry

The CAD model used in this validation case is a centrifugal pump, shown below:

Pump Validation Multi-purpose Geometry Blades — Figure 2: Pump Blade geometry

The dimensions of the centrifugal pump are listed in Table 1:

Dimension	Value \([m]\)
Upstream Length	0.041
Downstream Length	0.05
Inlet Diameter	0.075
Outlet Diameter	0.065
Pump Inside Diameter	0.075
Pump Outside Diameter	0.137

Table 1: Centrifugal pump dimensions

Analysis Type and Mesh

Analysis Type: Steady-state and Transient, Multi-purpose with K-Epsilon turbulence model

Mesh and Element Types:

The mesh was created with SimScale’s Multi-purpose Cartesian mesh. The automated mesher was used with increasing fineness for the global mesh, without the use of specific region refinements.

Mesh Sensitivity

The Multi-purpose meshing algorithm with hexahedral cells was used to generate the mesh. The mesh sensitivity study has been performed for the flow rate of 30 \( \frac{m^3}{h} \) using the automated mesh function with increasing fineness. The results of the sensitivity study can be seen in Figure 3:

Based on the mesh sensitivity study the automated mesh at level 4 was selected to perform the simulations for the whole operating range of the pump. The mesh for the pump can be seen in Figure 4:

Pump Validation Multi-purpose Mesh Geometry — Figure 4: Mesh within the flow domain with fineness level 4.

Simulation Setup

Three different volumetric flow rates were simulated. Constant pressure was set at the inlet and for all three volumetric flow rates at the outlet, the rotational speed of the pump was kept constant. The boundary conditions set for the fluid and the pump can be seen in Figure 5 and Table 2 respectively.

Fluid:

Water
- Kinematic viscosity \((\nu)\): 9.3379e-7 \(\frac{m^2}{s}\)
- Desity \((\rho)\): 997.33\(\frac{kg}{m^3}\)

Boundary Conditions:

Boundary Condition	Value
Velocity Outlet	(30, 50, 60) \( [\frac{m^3}{h}] \)
Totalt Pressure Inlet	1.013e+5 \([Pa]\)
No-slip wall	Pump housing wall surfaces
Rotation Speed MRF Zone	303.7 \([\frac{rad}{s}]\)

Table 2: Boundary conditions for the pump analysis.

Result Comparison

To compare the results obtained with SimScale with the experiment of WANG Xiu-yong and WANG Can-xing \(^1\), the pressure difference across the pump and the power consumption of the pump are measured.

pressure drop versus flow rate for Multi-purpose centrifugal pump — Figure 6: Pressure Head comparison of results obtained by SimScale and the reference.

power versus flow rate for Multi-purpose centrifugal pump — Figure 7: Power comparison of results obtained by SimScale and the reference

Remarks

The deviation of the results obtained with SimScale compared to the results obtained by WANG Xiu-yong and WANG Can-xing is shown in Figures 8 and 9. The deviation is small for all volumetric flow rates. For the pressure difference, the steady-state approach provides better accuracy, while the transient solution has a smaller deviation in the prediction of the power.