双级轴向旋流器气量分配对流场特性影响的数值模拟与试验验证

Numerical Simulation and Test Verification of the Influence of Airflow Splits on the Flow Field Characteristics in Dual-axial Swirlers

为了探究双级轴向旋流器气量分配对流场特性的影响,对相同进口条件下不同旋流器流场特性进行数值模拟,并结合流量特性试验和粒子图像测速仪流场试验进行验证。结果表明:当第1、2级旋流器气量比由0.32增大到1.48时,旋流器下游轴向、径向速度降低,气流扩张角、回流区宽度以及回流率均减小;不同气量分配的第1、2级旋流在文氏管出口与套筒出口之间剧烈掺混,经过套筒出口后,旋流数均小于0.4;在相同的结构形式下,不同气量分配的双级旋流器通过改变第1、2级旋流器在文氏管出口处的旋流数,进而改变了第1、2级旋流相互掺混的强度,并最终影响了下游流场。

In order to explore the influence of airflow splits on the flow field characteristics of dual-axial swirlers,the flow field characteristics of different swirlers under the same inlet conditions were numerically simulated and verified by combining the flow characteristic test and PIV flow field test.The results show that when the swirl airflow ratio of primary to secondary swirler increases from 0.32 to 1.48,the downsteam axial velocity and radial velocity decrease,the airflow expansion angle,the width of recirculating bubbles and the reverse flow rate decrease.The swirl airflow of primary to secondary swirler with different airflow splits are strongly mixed between the venturi outlet and the sleeve outlet.After the swirl airflow passing through the sleeve outlet,the swirl numbers are less than 0.4.In the same structure,the different airflow splits of the dual-axial swirlers changes the swirl number of the primary and secondary swirler at the outlet of the venturi,and then changes the mixing intensity of the primary and secondary swirler,and finally the downstream flow field is affected.