直流式风洞风扇段三维流场特性分析

Analysis of three-dimensional flow field of fan section in straight-flow wind tunnel

针对某直流低速风洞风扇段的三维流场特性,研究了风扇系统中风扇、整流罩、止旋片三种部件对风扇段三维流场特性的影响情况。对比并分析只有风扇、有风扇与整流罩、有整流罩和风扇以及止旋片的三种结构的风扇系统对于风扇段内部流场速度分布、出口处湍流强度以及流场迹线的影响,研究发现:整流罩、止旋片两个部件对于风扇段内部流场质量具有显著的提升作用。对比并分析风扇叶片数依次为5、7、9,风扇安装角依次是35°、40°、45°,整流罩及止旋片结构不变情况下的共9组风扇系统模型对风扇段内部流场压力分布、速度分布以及流场流线等气动特性的影响,研究发现:风扇叶片安装角为35°,叶片数为5时风扇段内部流场特性最好,安装角为35°,叶片数为5是扇叶的最终选择参数。最后,针对叶片数为5,安装角35°结构的扇叶进行流固耦合分析,模拟仿真发现风扇5个叶片受力情况一致,其中叶尖部位的变形量最大,最大应力集中在叶根部位,符合风洞设计要求。

Aimed at the 3D flow field characteristics of fan section of straight -flow low -speed wind tunnel,the influence of fan,fairing and straightening vanes in fan system oil the three- dimensional flow field characteristics of fan section were studied. The characteristics of the three types of fan systems with the fan only, with the fan and the fairing, with the fairing, the fan and straightening vanes were compared. The velocity distribution inside the fan section,the turbulence intensity at the outlet and the trajectory of flow field of the three fan systems were obtained. It was found that the two parts of tile fairing and the straightening vanes have a significant effect on the quality of the flow field in the fan section. When the installation angle of fan blade is 35 degrees and the number of blades is 5,the flow field in the fan section is the best. The fluid solid coupling analysis of the fan blades was carried out. The simulation results showed that the stress of the 5 blades is the same. The deformation of the blade tip is the largest and the stress of the blade root is largest, which accords with the design re- quirement of the wind tunnel.