柱形涡发生器强化撞击流反应器流场特性的数值模拟

Numerical simulation of flow field characteristics enhanced by cylindrical vortex generator in impinging stream reactor

利用数值模拟方法分析设有柱形涡发生器的撞击流反应器的流场特性,优化了柱形涡发生器的尺寸与位置参数,考察了柱形涡发生器尺寸与位置参数对撞击流反应器流场结构、速度分布、湍流尺度和混合性能的影响。结果表明,柱形涡发生器直径D=10 mm时,反应器内旋涡数量最多,涡系影响范围最广;D<10 mm时,旋涡数量减少;D>10 mm时,涡系影响范围减小。柱形涡发生器横向间距的增加使反应器内旋涡数量减小,涡系影响范围增大。随着柱形涡发生器横向间距、纵向间距的增加,撞击流反应器径向流速、湍流尺度和混合强度均先增大后减小。当柱形涡发生器横向间距K=5 mm、纵向间距J=70 mm时,撞击流反应器混合效果最佳。

Impinging stream reactor is widely used in absorption,extraction,and preparation of ultrafine powders due to its good mixing performance.The flow field characteristics of impinging stream reactor are closely related to the mixing performance.Based on impinging stream reactor,the use of a vortex generator and other turbulence elements to improve the flow state of the flow field,enhance the flow performance,and mixing effect of impinging stream reactor needs further research.In this work,the numerical simulation method is used to analyze the flow field characteristics of impinging stream reactor with a cylindrical vortex generator and optimize the size and location parameters of the cylindrical vortex generator.The effects of size and location parameters of cylindrical vortex generators on flow field structure,velocity distribution,turbulence scale,and mixing performance of impinging stream reactor are investigated.The results show that when the diameter of cylindrical vortex generator D is equal to 10 mm,the number of vortices in the impinging stream reactor is the largest,and the influence range of the vortex system is the widest.When the diameter of cylindrical vortex generator D is less than 10 mm,the number of vortices decreases.When the diameter of cylindrical vortex generator D is greater than 10 mm,the influence range of the vortex system decreases.The number of vortexes in the impinging stream reactor decreases and the influence range of the vortex system increases with the increase of the transverse spacing of the column vortex generator.The radial velocity,turbulence scale,and mixing intensity of impinging stream reactor first increase and then decrease with the increase of transverse and longitudinal spacing of cylindrical vortex generators.When the transverse spacing of the cylindrical vortex generator K is equal to 5 mm and the longitudinal spacing of the cylindrical vortex generator J is equal to 70 mm,the mixing effect of the impinging stream reactor is the best.