Study On Design Optimization Of Hand Fan

Fan is a kind of very common turbomachine in our daily life and production,which is widely used in various fields of industrial production.At the same time,the energy consumption of all kinds of fans accounts for a large proportion of the total power consumption in China every year.Therefore,it is of great significance to optimize the fan in order to improve its aerodynamic performance and operation efficiency.Based on the design of 9-19 centrifugal fan,this paper studies the numerical simulation of hand-held fan under different working conditions,observes and analyzes the internal flow field of the fan,aiming at improving the total pressure and internal efficiency of the fan,and puts forward a variety of optimized design schemes of impeller profile.The main work is divided into the following aspects:Taking 9-19 centrifugal fan as a reference to carry out the similar design of hand-operated fan,this paper first introduces the research work of domestic and foreign scholars on the numerical simulation of fan flow field and the optimization design of fan performance,then introduces the basic theory of fan numerical simulation,as well as the basic working principle and various performance parameters of fan.The 3D modeling of hand-held fan is completed by Solid Works software,and then the grid division and numerical calculation are carried out by Star-ccm+12.0 software.It is found that the fan has the highest internal efficiency under the condition of flow coefficientφ=0.025（fan flow Q=0.02467m³/s）.Then,the gas flow in the fan is analyzed from three aspects of absolute velocity,static pressure and total pressure distribution,which provides theoretical reference for the follow-up fan blade profile optimization.Based on the numerical simulation results of the original hand-held fan,this paper puts forward five improved schemes for the inlet angle of the fan blades,and carries out the numerical simulation under different working conditions for the grid division of the fan models under different schemes.Through the analysis of the total pressure coefficient curve and internal efficiency curve of each scheme fan,it is found that the total pressure increases with the increase of fan flow,and the internal efficiency increases first and then decreases.Comparing the internal efficiency curves of each model,the fan with blade inlet angleβ₁=40°is selected as the optimization model.The maximum internal efficiency of the optimized fan under the condition of flow coefficientφ=0.03（fan flow Q=0.02961m³/s）,the maximum internal efficiency can reachη_in=46.6%,which is 1.32%higher than the original manual fan.