Analysis of characteristics of pressure fluctuation inside submersible mixer
Tian Fei1, Shi Weidong2, Lu Xining3, Zhang Desheng2, Lang Tao2
1.School of Energy and Power Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, China; 2.National Research Center of Pumps, Jiangsu University, Zhenjiang, Jiangsu 212013, China; 3.Shanghai Kaiquan Pump(Group)Co.Ltd., Shanghai 201700, China
Abstract:For a thorough study on the vibration induced by pressure fluctuation inside a submersible mixer, the unsteady, three-dimensional turbulent flow driven by a specific submersible mixer in a se-wage treatment pool is simulated by using software-Fluent 6.3 and Gambit. The RNG k-ε turbulence model, PISO algorithm, rigid-lid approximation and sliding mesh are adopted in the simulation. The pressure fluctuation characteristics in the impeller of submersible mixer are clarified based on an examination of the unsteady flow field features in the impeller and pool. It is shown that the flow of the fluid inside the impeller and in the vicinity of impeller exhibits an obvious periodic feature, i.e. the fluid domain with high pressure and low relative velocity and the domain with low pressure but high relative velocity vary periodically with the rotating impeller. The pressure fluctuation frequency of the fluid in the impeller entrance, outlet and inside the impeller is closely related to impeller rotational frequency, and the predominant frequency is 2 times the blade passing frequency. The results may provide a reference for application of the mixers.
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