Design and analysis of a radial diffuser in a single-stage centrifugal pump

Figures & data

Figure 1. Velocity triangle at impeller outlet, inlet and outlet of diffuser.

Figure 2. Hydraulic structure of the model pump.

Table 1. Main geometric parameters.

Hydraulic components	Structure parameters	Value
Impeller	Hub diameter dh (mm)	0
	Inlet diameter Dj (mm)	94
	Outlet diameter D2 (mm)	169
	Outlet width b2 (mm)	14
	Vane inlet angle β1 (°)	17
	Vane outlet angle β2 (°)	22
	Vane number ZB	5
	Vane wrap angle ϕi (°)	145
Radial diffuser	Inlet diameter D3 (mm)	173
	Outlet diameter D4 (mm)	238
	Inlet width b3 (mm)	16
	Outlet width b4 (mm)	24
	Inlet angle β3 (°)	10
	Outlet angle β4 (°)	21
	Vane number ZR	8
	Vane wrap number ϕd (°)	70
Volute	Inlet diameter of pump Ds (mm)	100
	Outlet diameter of pump Dd (mm)	80
	Base circle of volute D5 (mm)	240

Figure 3. Single-arc design method for the radial diffuser.

Figure 4. 3D model of the flow field calculation domain.

Table 2. The independence check of the mesh.

	Mesh size (mm)
Number	Impeller	Radial diffuser	Volute	Total mesh	H (m)	η (%)
1	2.5	1.4	2.4	1135527	7.23	72.6
2	2.3	1.2	2.2	1510601	7.23	72.8
3	2.1	1.1	2.1	1834856	7.23	72.6
4	2.0	1.0	2.0	2236175	7.24	72.7
5	1.8	0.9	1.8	2772271	7.24	72.8
6	1.7	0.8	1.7	3217684	7.24	72.7

Figure 5. H-Q curves for different vane outlet angles β₄.

Figure 6. η-Q curves for different vane outlet angles β₄.

Figure 7. Hydraulic loss in the radial diffuser for different vane outlet angles β₄.

Figure 8. Velocity distribution in the pump middle plane at the design flow rate for: (a) β₄ = 3°, (b) β₄ = 6°, (c) β₄ = 10°, (d) β₄ = 15°, (e) β₄ = 25°, and (f) β₄ = 45°.

Figure 9. Total efficiency in the pump and the integral hydraulic loss in the radial diffuser and the volute at the design condition.

Figure 10. H-Q curves for different vane outlet thicknesses t.

Figure 11. η-Q curves for different vane outlet thicknesses t.

Figure 12. Hydraulic loss in the radial diffuser for different vane outlet thicknesses t.

Figure 13. Velocity distribution in the pump middle plane at the design flow rate for: (a) t = 2 mm, (b) t = 5 mm, (c) t = 8 mm, and (d) t = 10 mm.

Figure 14. Total efficiency in the pump and the integral hydraulic loss in the radial diffuser and the volute at the design condition.

Figure 15. H-Q curves for different vane numbers Z_R.

Figure 16. η-Q curves for different vane numbers Z_R.

Figure 17. Hydraulic loss in the radial diffuser for different vane numbers Z_R.

Figure 18. Velocity distribution in the pump middle plane at the design flow rate for: (a) Z_R = 6, (b) Z_R = 7, (c) Z_R = 8, (d) Z_R = 9, (e) Z_R = 11, and (f) Z_R = 12.

Figure 19. Total efficiency in the pump and the integral hydraulic loss in the radial diffuser and the volute at the design condition.

Figure 20. The design contrast between the new and old diffusers.

Figure 21. The new radial diffuser.

Figure 22. The model pump.

Figure 23. Sketch of the test bed.

Figure 24. Contrast curves between the new model and the primary model.