Numerical investigation on flow mechanisms of a squirrel cage fan

作     者：Wang, Ke Ju, Yaping Zhang, Chuhua 

作者机构：Xi An Jiao Tong Univ Sch Energy & Power Engn 28 West Xianning Rd Xian 710049 Shaanxi Peoples R China Xi An Jiao Tong Univ State Key Lab Strength & Vibrat Mech Struct Xian Shaanxi Peoples R China 

出 版 物：《PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART A-JOURNAL OF POWER AND ENERGY》 (机械工程师学会会报；A辑：动力与能源杂志)

年 卷 期：2019年第233卷第1期

页      面：3-16页

核心收录：

学科分类：08[工学] 0807[工学-动力工程及工程热物理] 0802[工学-机械工程] 

基　　金：National Key Research and Development Project of China [2016YFB0200903] National Natural Science Foundation of China 

主　　题：Squirrel cage fan computational fluid dynamics simulation inactive zone sudden diffusion-expansion effects 

摘      要：Squirrel cage fan has found wide applications in heating, ventilation and air-conditioning as well as other cooling systems. Although many studies have been conducted to investigate the performance of the squirrel cage fan, the complex flows and the associated flow mechanisms have not been fully elucidated. In this paper, computational fluid dynamics simulations are performed for a comprehensive analysis of the flow throughout a whole squirrel cage fan. A novel representation technique is proposed for a vivid and quantitative description of the flow velocity distributions at the impeller inlet and outlet to aid a heuristic analysis of the complex flows in squirrel cage fan. The pressure gradient distributions, together with the pressure itself, along the volute wall are also extracted and analyzed to explore the local flow conditions of the volute profile with four segmental arcs. The results show that the proposed representation technique is capable of effectively measuring the circumferentially nonuniform flow conditions at both the impeller inlet and outlet. The strong interaction between the impeller and the volute tongue induces reversed flows at both the impeller inlet and outlet, which further aggravates the circumferential nonuniformity of inactive zone and the upstream impeller flow field. Despite the first-order continuity of the volute profile itself, there are strong variations of tangential pressure gradients and sudden diffusion-expansion effects at the junctions of adjacent arcs. These findings benefit a deep understanding of the complex flow mechanisms within the squirrel cage fan.