Case Study of Impeller Profile With Suitable Rotative Guidevane

In the previous paper, the optimum meridian profile of multi-stage impeller with guidevane was obtained by means of diffusion factor using twelve shape factors. The coefficient of peripheral absolute velocity at impeller inlet kCu1c means the effect of multi-stage impeller with guidevane. In this paper, the optimum meridian profile of multi-stage or single-stage impeller with rotative guidevane was obtained by means of fifteen shape factors. The fifteen shape factors mean impeller inlet relative flow angle β1, impeller turning angle Δβ, impeller axial velocity ratio kc12 = Cm2/Cm1, impeller diameter ratio kd12 = D1c/D2c, impeller outlet hub-tip ratio ν2, impeller tip solidity σt(imp), impeller mid span solidity σc(imp), impeller hub solidity σh(imp), guidevane tip solidity σt(gv), guidevane mid span solidity σc(gv), guidevane hub solidity σh(gv), guidevane axial velocity ratio kc34 = Cm4/Cm3, guidevane diameter ratio kd34 = D3c/D4c and rotational speed ratio Rn = ngv/nimp. The suitable rotational speed ratio means suitable rotational speed of guidevane. The axial velocity ratio and diameter ratio of guidevane means the optimum meridian profile of guidevane outlet. In the 15th dimensional optimum method, the hydraulic efficiency and suction specific speed are calculated by diffusion factor. This method is also used for the modification of multi-stage or single-stage present impellers and guidevanes.