CAJ | 학술논문

针对小型高速离心风扇进行了数值与试验研究.离心风扇封闭叶轮与外机匣之间存在0.7 mm的间隙,叶轮的转速为34 000 r/min.构造了有/无间隙的计算模型,使用k-ωSST湍流模型和非结构网格进行了非定常数值模拟.在一个标准测试平台进行了总体性能的测试,利用CFD技术进行了全三维非定常流场的计算,获得了离心风扇的总体性能和各流动部件的流场结构.由于风扇叶轮与外机匣之间存在的间隙以及叶轮进出口之间的静压差,使得间隙内存在很强的回流,并在叶轮进口处产生很强的流动干涉,从而改变了叶轮进口的流动状况,对离心风扇的总体性能产生很大的影响.
침대소형고속리심풍선진행료수치여시험연구.리심풍선봉폐협륜여외궤갑지간존재0.7 mm적간극,협륜적전속위34 000 r/min.구조료유/무간극적계산모형,사용k-ωSST단류모형화비결구망격진행료비정상수치모의.재일개표준측시평태진행료총체성능적측시,이용CFD기술진행료전삼유비정상류장적계산,획득료리심풍선적총체성능화각류동부건적류장결구.유우풍선협륜여외궤갑지간존재적간극이급협륜진출구지간적정압차,사득간극내존재흔강적회류,병재협륜진구처산생흔강적류동간섭,종이개변료협륜진구적류동상황,대리심풍선적총체성능산생흔대적영향.
A centrifugal fan with the high speed and compact dimensions is studied numerically and experimentally. The centrifugal fan consists of a shrouded impeller rotating at 34 000 r/min with a small tip clearance 0.7 mm to the fixed outer casing. Computational models with/without the tip clearance are built and the k-ω shear stress transport (SST) turbulence model and the unstructured mesh are applied to the numerical simulation for unsteady solutions. The overall performance is measured on a standard experimental bench and the major flow feature of each component inside the centrifugal fan is numerically investigated. In the presence of the tip clearance due to the difference of static pressure between leading and trailing edges of the clearance, i. e. , leading and trailing edges of the impeller, a strong return flow exists inside the clearance passage and re-circulates the main stream inside the impeller passage, and produces the strong flow interaction, thus changing the flow field and influencing the overall performance.