Numerical analysis of an annular water–air jet pump with self-induced oscillation mixing chamber

Abstract

This paper presents an improved annular water-air jet pump concept design through integrating a self-induced oscillation mixing chamber with the conventional annular jet pump (AJP). The internal flow characteristics for both conventional and improved AJP were numerically investigated and compared by a validated computational fluid dynamics model. The numerical comparison demonstrated an approximately 10% pumping performance increase compared with the conventional pump, which is mostly attributed to the improved mass and energy transfer along the oscillating phase interface. Furthermore, transient flow analysis was conducted to resolve the unsteady self-introduced oscillation. The results revealed the self-introduced oscillation induces a continuous break-up and formation of fresh water-air interfaces, which exhibits a periodic feature with a dominant frequency of 147 Hz for the current design under given operational conditions. This study contributes toward a better understanding of the internal annular water-air jet pump flow patterns, and also demonstrates the feasibility of incorporating self-introduced oscillation chamber into AJP design.

Improvement of the Axial-Jet-Pump Performance using Modified Mixing Chamber Configuration and Inlet Swirling Flow

“…= P k t + Cd w Dw + @ @ x j ( + w t ) @! @ x j ; (15) where D w is the dissipation term and Cd w is the crossdi usion term for !, respectively. More speci cs are found in [28{30].…”

“…Xiaogang et al [15] investigated numerically the ow characteristics for both traditional and ameliorated annular-water-air-jet-pump. Their study improved the annular-water-jet-pump performance by 10% compared with the traditional pump.…”

Experimental and numerical investigation of two-phase flow and mass transfer in a self-excited oscillation pulse jet pump

“…1, where water is used as the driving fluid and air is used as the entrained fluid. As mentioned earlier, the main difference between the conventional design and the improved design is the self-excited oscillation chamber, which is an enlarged cylindrical cavity with a cone-shaped impinge downstream sidewall, and its geometrical configuration was adopted from our previous work (Deng et al, 2017). The basic principle of the annular self-excited oscillating jet pump is that the pressurized working fluid forms a high-speed jet through the annular nozzle.…”

Influence of the vertically arranged front injector system on the performance and operational stability of the short jet pump

“…The effect of the hydraulic characteristics of the jet pump is discussed, and the optimal mixing chamber structural parameters are derived. Deng et al (2017) investigated the modified jet pump by numerical simulation and found that self-introduced oscillations cause successive rupture and the formation of liquid-gas interfaces, and the phenomenon is characterized by periodicity. The results of this study help understand the flow pattern within the liquid-air jet pump and, thus, improve the unsteady operation of the pump.…”