An active method to control cavitation in a centrifugal pump by obstacles

Abstract

In this article, we proposed an active method of obstacle attached on the blade to control cavitation in centrifugal pump. The modified shear stress transport k-v model with a local density correction for turbulent eddy viscosity combined with Kubota cavitation model was employed to simulate three-dimensional unsteady flow. The simulated external performance agreed fairly well with experiment observation. The results show that the obstacles of appropriate height can cause little disturbance to external performance. The over-high obstacle can cause larger perturbation to deteriorate the flow field at large flow rate point. The obstacle of appropriate height can induce relative high pressure and optimize the flow structure to suppress the cavitation, which is the main mechanism of cavitation control in a centrifugal pump. The passages would be blocked if over-high obstacle is arranged, which is bad to suppress the cavitation in centrifugal pumps. The effects of 1/2 the outlet width of impeller for cavitation suppression are optimal when the bubbles reach close to the obstacle, which degrade the amplitude of dominate frequency and simultaneously attenuate the bubble volume. When cavitation completely developed, the obstacle of any height can keep the cavity volume attenuating and 1/2 of the outlet width of impeller is best.

Influence of Geometric Parameters of Tiny Blades on the Shroud of a Centrifugal Pump on the Cavitation Suppression Effect

“…Adding inducers to the impeller inlet (Acosta, 1958), inducing partial high-pressure fluid injection into the inlet from the pump outlet (Wong et al, 1965;Cui et al, 2019), etc., are methods to suppress cavitation by increasing the impeller inlet pressure. Zhao and Zhao, (2017) placed obstacles at suitable locations on the pressure surface of the blade to inhibit cavitation development. Wei et al (Wei et al, 2021) improved the fluid dynamics at the inlet of centrifugal pumps by adding a deflector plate, which contributed to the suppression of cavitation instability in high-speed centrifugal pumps.…”

Experimental Study on the Effect of Gas Volume Fraction on the Cavitation Performance of a Low-Specific-Speed Centrifugal Pump

“…A lot of numerical calculation studies and experimental studies have been carried out on the cavitation performances of centrifugal pumps [10,11]. Georgios et al studied the inception and development of cavitation in three different impellers using visual experiments and monitored the changes of the head, vibration, and noise.…”

Performance improvement of a high-speed aero-fuel centrifugal pump through active inlet injector

“…In Wang et al., 42 the influence of inlet guide vanes on unsteady flow is numerically investigated. In Zhao and Zhao, 43 the obstacle attached on the blade is proposed to regulate the flow field of the pump, and it is an active flow control method. Among most of these methods, the flow characteristics are regulated by changing geometrical parameters.…”

“…Although extensive studies have been conducted for flow control of centrifugal pumps to achieve excellent satisfactory internal flow field and overall hydraulic performance, there are some difficulties that need to be addressed. 1) the volume of inlet domain 38,39 or parameters of impeller 41–43 are treated as the main factors in most of the typical flow control strategies, but such strategies need trade-off between efficiency and pressurization; 2) in order to improve operating efficiency and maintain system stability for the compressor of an aero-engine, 46,47 the injector is commonly used to solve serious flow problems. Only few of them, such as, 44 apply the injector to an inducer.…”