Study of the potential use of hydrodiodes to enhance the volumetric efficiency of a centrifugal pump

BACKGROUND: For centrifugal pumps, especially those with low specific speed coefficients, the volumetric efficiency is a very important parameter that largely determines the overall efficiency of the pump. Meanwhile, the amount of leakage in the flow part of the pump depends on the shape and size of the slot seals on the impeller. In this paper, the attempt to apply the well-known operational principle of a hydrodiode is made in order to reduce volumetric losses in the pump through a reduction in the flow rate coefficient of the slot seal, whose surface is profiled according to the principles of a hydrodiode.

AIM: Analysis of the possibility of utilizing the hydrodiode-like grooves on the surface of a slot seal in order to reduce the flow rate of liquid through the seal based on the computational fluid dynamics methods.

METHODS: The computational fluid dynamics method based on the solving of discrete analogs of the basic hydrodynamic equations is used in this paper.

RESULTS: The parameters of liquid flow in the slot seals with smooth surfaces, concentric grooves, and proposed profiled hydrodiodes in various sizes and shapes have been calculated. The flow rate coefficients for each type of seal have been determined, and comparative graphs have been built.

CONCLUSION: Based on the findings of this study, it can be stated that, overall, the use of hydrodiodes does not give significant advantages over the concentric groove with significantly increased complexity in manufacturing.