多层桨功率准数的CFD模拟研究

CFD Simulation Study on Power Number of Multiple Impellers

为考察多层桨的功率准数,采用CFD方法对不同桨型及层间距的组合进行模拟。研究发现,对多层轴流桨以及轴流桨和径流桨的组合,最上层搅拌器的功率准数基本不变,3层搅拌器时,中间层搅拌器的功率准数降低为基准值的60%。对多层轴流桨PBT的组合,由于流型的影响,下部搅拌器的功率准数有所降低,层间距与桨径相等时,2层PBT的功率准数为单层桨的1.75倍,3层PBT时,总功率准数为单层桨的2.35倍。对径流桨与轴流桨的组合,径流桨的功率准数和最上层轴流桨的功率准数都基本不变。研究结果可为工业中搅拌功率的计算提供依据。

To inspect the power number of multiple impellers in a stirred tank, the combination of different impeller type and layer spacing were simulated by means of computational fluid dynamics(CFD) techniques. The simulation results indicated that the power number of the top blender basically remain unchanged when the combination were multiple axial flow impeller or axial flow impeller with radial flow impeller, the power number of the blender in the middle layer decreased to 60% of the benchmark when the blenderhad three layer. The power number of the lower blender reduced due to the influence of flow pattern when the combination were multilayer axial flow inspeller PBT, the power number of the two-layer PBT was 1.75 times that of the single layer when the layer spacing equal the impeller diameter, and the total power number of the three-layer PBT was 2.35 times that of the single layer. The power number of radial flow impeller and the top axial flow impeller basically remain unchanged when the combination were radial flow impeller with axial flow impeller. Research results could provide the basis for industry stirring power calculation.