旋风分离器内旋转流湍流特性的实验分析

Experimental Analysis of Turbulence Characteristics of Swirling Flow in Cyclone

采用热线风速仪(Hot wire anemometry,HWA)测量了300mm×2000mm旋风分离器内的瞬时切向速度,进而分析旋转流的湍流特性。基于测量的瞬时切向速度计算的湍流强度表明,切向湍流强度是由气流自身湍流脉动产生的湍流强度和气流旋转波动产生的湍流强度两部分构成。在壁面附近,切向湍流强度主要是旋转流自身的湍流脉动作用,旋转流波动对其影响较小;而在几何中心附近,切向湍流强度不仅有旋转流自身的湍流脉动,而且更主要是旋转流摆动的影响。由于旋风分离器内旋转流的旋转中心与几何中心不重合,形成了旋流的摆动,使中心区域的计算切向湍流强度骤增,远大于壁面区域的切向湍流强度。

The turbulence characteristics of swirling flow in the cyclone were studied based on measured real tangential velocity by hot wire anemometry （HWA）. The mechanics of turbulence intensity of the real tangential velocity was analyzed. The measured results showed that the turbulence intensity flow, and the turbu real tangential veloc of the tangential velocity was affected largely by the fluctuation of swirling ence intensity in the center region was higher than that near the wall. As the ty was composed of the high frequency turbulence velocity and low frequency fluctuation velocity, the turbulence intensity was not only influenced by the turbulence flow itself, but also by the fluctuation of swirling flow resulted from gas swirling flow center deviating geometry center. So, the real tangential velocity fluctuated significantly in the center region of cyclone, and a little near the wall of cyclone, resulting in the great increase of turbulence intensity in the center region.