中文摘要：

本文提出在离心叶轮轮盖与叶片之间开缝,使得叶片压力面侧的高压气体射流到吸力面侧的低速尾迹区,从而直接给叶轮内的低速流体提供能量,减弱了叶轮内由于二次流所导致的射流-尾迹结构,并可用于消除或解决部分负荷时常发生的离心叶轮积灰问题。对某离心风机整机的数值模拟表明,在设计流量和小流量情况下,叶轮开缝后使叶片表面分离区域减小,整个流道速度分布更为均匀,改善了叶轮内部流场的流动状况,提高了离心叶轮性能和整机性能。研究表明,本方法对于提高离心式流体机械性能是有效的。

英文摘要：

A new kind of centrifugal impeller with slots cut along the blade ends close to shroud is proposed. Due to the pressurized air flows from pressure sides to suction sides of the blades and the additional energy supplys to the flow with low velocity inside the passages in the impeller, the jet-wake flow at exit of the impeller caused by secondary flows is weakened and the problems of dust or ash accumulated on the blades often encountered with partial loads are expected to be solved to some extend. The numerical investigations of flow fields in a centrifugal fan with slots along the blade ends reveal that, at design and low flow rates, the flow separation zones in flow passages become smaller and the exit velocity fields become more uniform, which indicates that the flow fields in the impeller are improved and the performances of both the centrifugal impeller and the fan are enhanced. The research shows that the new approach is useful to improve the characteristics of the centrifugal fluid machinery.