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| Influence of airfoil and installation elevation of hyperboloid agitator on mixing performance |
| SHI Junfeng2, ZHENG Yuan1*, ZHANG Haisheng2, GUO huajuan2 |
| 1. School of Energy and Electricity, Hohai University, Jiangsu, Nanjing 211100, China; 2. Innovation Research Institute of Hohai University, Nanjing, Jiangsu 210098, China |
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Abstract NX software was used to establish the solid model, and Fluent 18.0 software was used to analyze the three-dimensional turbulence. Through unstructured grid and moving coordinate system technology, standard k-ε turbulence calculation model and SIMPLEC algorithm were used to solve the velocity pressure coupling problem. On the basis of the original hyperbolic agitator airfoil, the blades were superimposed horizontally, and the mixing flow field of the hyperboloid agitator in the oxidation tank of 9 m×9 m×5 m under the two airfoils was calculated. The flow field near the blades of the hyperbolic stirrer before and after optimization and the turbulent kinetic energy change in the specific area under different installation heights were compared and analyzed. The blade extension line of hyperbolic stirrer was helix. The research and calculation show that the upstream surface of the blade is the surface directly impacting with the incoming flow, and the optimal one is the concave side of the spiral line and at an acute angle with the turntable; the optimal back water surface is the vertical plane perpendicular to the turntable; and adding an inclined plane behind the back surface can rectify the accelerated water body and make the radial mixing range of the agitator wider. When the installation elevation is h=1 000 mm, the average velocity in the pool reaches 0.710 m/s, which is 0.140 m/s higher than that before optimization, and the average turbulent kinetic energy reaches 0.088 J/kg and 0.043 J/kg respectively. The average turbulent kinetic energy of main areas increases from 0.015 J/kg to 0.028 J/kg.
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Received: 18 October 2020
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