%0 Journal Article %T A New Proposed Return Guide Vane for Compact Multistage Centrifugal Pumps %A Qihua Zhang %A Weidong Shi %A Yan Xu %A Xiongfa Gao %A Chuan Wang %A Weigang Lu %A Dongqi Ma %J International Journal of Rotating Machinery %D 2013 %I Hindawi Publishing Corporation %R 10.1155/2013/683713 %X For widely used multistage centrifugal pumps, their former structures are so bulky that nowadays growing interest has been shifted to the development of more compact structures. Following this trend, a compact pump structure is provided and analysed. To maintain the pump¡¯s pressure recovery, as well as to meet the water flow from the impeller, a circumferential twisted return guide vane (RGV) is proposed. To validate this design method, the instantaneous CFD simulations are performed to investigate the rotor-stator interventions. Within the impeller, the pressure fluctuation is cyclic symmetry, where the impeller frequency dominates. At the zone where flow leaves impeller for RGV, the pressure fluctuation is nonperiodic, the impeller frequency is major, and the rotation frequency is secondary. Within RGV, the periodic symmetric fluctuation is recovered, where the rotation frequency is governing. The fluctuation decreases from seven cycles within impeller to two cycles within RGV, indicating that the flow from impeller is well handled by RGV. To examine the pump¡¯s performance, a prototype multistage pump is designed. The testing shows that the pump efficiency is 57.5%, and the stage head is 9£¿m, which is comparable to former multistage centrifugal pumps. And this design is more advantageous in developing compact multistage centrifugal pumps. 1. Introduction To meet variable flow angles into gas turbines, hydraulic runners, and so forth, inlet guide vane (IGV) is adopted to keep them operating at peak performance [1¨C5]. For compressors, fans, pumps, and so forth, IGV is also used to manipulate their operating load [6¨C11]. Outlet guide vane (OGV) is heavily used at downstream of low pressure turbines, fans, compressors, and pumps, where the rotating velocity can be effectively transformed to static pressure, reducing flow-induced vibration and noise [12¨C19]. Nozzle guide vane (NGV) is widely used in turbines. More specially, return guide vane (RGV) is applied for multistage centrifugal turbomachines, where RGV is functioned as an OGV with respect to its upstream stage; meanwhile, it is served as an IGV with respect to its downstream stage, which increases its design complexity [20¨C23]. In the first place, a suitable guide vane design is critical for overall stage performance. For IGV and OGV, flow in a mainstream direction is concerned, so airfoil is widely adopted in the streamwise direction, while in the spanwise direction, such strategies as free-vortex method, forced-vortex method, and radial-equilibrium method are available. To improve the performance %U http://www.hindawi.com/journals/ijrm/2013/683713/