“波纹”内壁搅拌槽内的湍流流动特性

摘要

This research developed a “waved-inner-wall” stirred vessel(WSV)by mounting some half-circle tubes on the inner wall to improve the mixing efficiency. The turbulent hydrodynamics within the vessel was studied using the compotational fluid dynamics(CFD) technique. By comparing the experimental and numerical results from literatures,the modeling and simulation methods were validated and subsequently used to study the flow fields and energy consumption. Effects of the tube size,number and mounting positions were studied. Results showed that compared with the standard stirred vessel,the “waved-inner-wall” stirred vessel had better uniformity of fluid velocity distribution with no obvious improvement turbulent kinetic energy. and negligible variation of energy consumption. Then the inner vessle was evenly equipped with 4 half-circle tubes(the radius of each tube was 1/20 of the vessel inner diameter),the low fluid velocity region behind the baffles and in the top region of the stirred vessel can be significantly reduced.%设计了一种“波纹”内壁搅拌槽，通过在内壁上安装一定数量的半圆管，以增强搅拌效果，并采用计算流体动力学方法对其内部流动特性进行了分析。通过与文献中的实验及模拟结果的比较，验证了所建数值模型及模拟方法的可靠性，随后对不同半圆管尺寸（半径）、数量和安装位置时搅拌槽内的流场结构和功率消耗进行了研究。结果表明，与标准搅拌槽相比，“波纹”内壁结构尽管不会明显增强流体的湍流程度，但能提高流体速度分布的均匀程度，而且功率消耗没有明显变化；当在搅拌槽内壁上均匀安装4根半径为搅拌槽直径1/20的半圆管时，能显著减少挡板后方及槽顶部流体的低速区。该结果为“波纹”内壁搅拌槽在过程工业中的应用奠定了基础。