开槽蜗舌对离心风机流场特性的影响

针对风机叶轮射流尾迹与蜗舌产生的动静干涉流场的特性,研究风机内部动静干涉流场的相互作用机制.以某离心风机为研究对象,通过对传统蜗舌的结构进行改进,在叶轮出口长度对应的蜗舌展向长度范围内开槽,采用数值计算的方法分析开槽结构的槽宽、槽深和间距等参数对离心风机的气动特性和风机内部流场分布的影响规律.计算结果表明:开槽蜗舌有助于改善风机的运行效率,减小尾迹对蜗舌前缘的冲击,延缓蜗舌下游边界层的流动分离,削弱叶轮与蜗舌之间的动静干涉作用,抑制蜗壳壁面的非定常压力脉动.

Study on Flow Field Characteristics of Slotted Volute Tongue Centrifugal Fan

According to the characteristics of the dynamic and static interference flow field produced by the jet wake and the volute tongue of the fan impeller, the interaction mechanism of the dynamic and static interference flow field inside the fan is studied. Through the improvement of the traditional volute tongue structure, a slot is slotted within the volute tongue span corresponding to the impeller outlet length. The influence of slot width, slot depth and slot spacing on the aerodynamic characteristics and internal flow field distribution of the centrifugal fan is analyzed by numerical method. The results show that slotted volute tongue can improve the efficiency of the fan, reduce the impact of Wake on the front edge of volute tongue, delay the flow separation of the downstream boundary layer of volute tongue, weaken the dynamic and static interference between impeller and volute tongue and suppress the unsteady pressure fluctuation on volute wall.