错位六弯叶桨搅拌假塑性流体流场特性数值模拟

Numerical Simulation on Flow Field Features of Pseudoplastic Fluids Stirred by the Impeller of Perturbed Six-bent-bladed Turbine

利用计算流体力学方法,以质量分数为1.25%假塑性流体黄原胶水溶液为研究对象,分别对错位六弯叶桨和六弯叶桨的搅拌流场特性进行了数值模拟,并做了对比分析,探讨了流场结构和时均速度分布的变化。数值模拟及分析结果表明,错位桨流场呈现不对称结构形式,从而可有效消除混合隔离区,提高混合效率;错位桨在径向速度和轴向速度分布方面均优于六弯叶桨,其速度峰值明显提高,搅动范围也显著增大,体现出了错位六弯叶桨的优势,是一种值得推广的搅拌器形式。

The flow field stirred by impeller of perturbed six-bent-bladed turbine（6PBT） and sixbent-bladed turbine（6BT）in a cylindrical vessel was studied respectively by means of computational fluid dynamics（CFD）. The test liquid used is pseudoplastic fluid, 1.25% （wt）xanthan gum solution. The flow field structure and the time-averaged velocity distribution were made a inquiry. The results show that the flow field of 6PBT impeller appears asymmetric structure, which can eliminate the isolated mixing region and improve the efficient of mixing. The radial velocity and axial velocity distribution of 6PBT impeller is superior to that of 6BT,which exhibits the advantages of 6PBT impeller with the higher peek speed and the larger stirring scope. So 6PBT impeller is worth application and dissemination.