新型内外组合桨搅拌湍流场的PIV测量和CFD模拟

利用PIV和CFD技术研究了湍流域内带有新型内外组合桨的搅拌设备内的流场。考察了不同转速比条件下,该搅拌桨产生的宏观流动场和湍动能分布。结果表明:在湍流域内,外桨搅拌行为的介入使得搅拌设备内流场的局部细节发生变化,但宏观流场结构不变。新型内外组合搅拌桨改善了搅拌罐内,尤其是罐体边壁区、罐底以及两内桨中间区域液体的湍动程度。当转速比较低时,有利于快速反应中介质的快速混合。

PIV Measurement and CFD Simulation of Turbulent Flow Fields Stirred by Novel Combined Inner-Outer Agitator

The PIV and CFD technique were adopted to investigate the turbulent flow fields in stirred vessels with novel combined inner-outer agitator.The velocity fields and turbulent kinetic energy stirred by the combined inner-outer agitator with different rotating speed ratios were analyzed.Results show that,in the turbulent flow regime,the introduction of outer agitator leads to the slight change of the velocity fields.The combined inner-outer agitator could enhance the turbulent level in stirred vessels,especially in the regions near the vessel wall and bottom,and the region located at mid-height of the two pitched paddles.The lower speed ratio could be beneficial to the rapid mixing of fluids.