The Study Of Optimal Design System Of Centrifugal Impeller Based On Velocity Distribution Control

As a kind of general machinery which is always used to convey gas,centrifugal fan is widely used in industries such as cement,electric power and steel.The centrifugal fan used in these industries always consume huge energy each machine.Thus,establishing an optimal design system of centrifugal fan impeller has important economic benefits.This paper has established an optimal design system of centrifugal fan impeller which can optimize the whole centrifugal impeller.Firstly,the formation mechanism and feature of the flow effects,which always caused the flow loss at the impeller passage,are studied;For instance,the development of boundary layer,secondary flow and stratification effects.The relationship between flow effects,velocity distribution and flow control parameters is set up.And the flow control parameters,such as maximum reduction ratio,loading coefficient are proposed.Secondly,through flow control parameters,the relationship between impeller structure parameters and flow characteristic is built,the optimization criterion and objective function is established.Through the velocity distribution,the relationship between blade profiles and flow control parameters is built,flow control parameters are summarized.And then reasonable and reliable velocity distribution model is obtained and established.The best velocity distribution depends on whether the boundary layer is the thinnest.Thus,the calculation of the boundary layer took the rotation and curvature of the blades into consideration is adopted to calculate the thickness of boundary layer.At last,the optimal design system of centrifugal fan impeller was established,design software program was compiled with c language.Finally,two different centrifugal fan impeller were optimized by this optimal system,the result of CFD numerical simulation shows that the efficiency of the optimal fan has increased clearly.Also,the growth of boundary layer is decreased,the separation is avoided,and secondary flow and stratification are restrained,it means that the optimal system is reliable.