Influence Of Tip End-plate On Static Characteristics And Noise Of Small Axial Fan

Small axial flow fan is the important equipment used for heat dissipation in home applains.Its ventilation affects the performance of heat dissipation and longevity of products,the aerodynamic noise it produces has a negative impact on people's working efficiency.Therefore,it is meaningful to do research on small axial fan.On basis of the prototype,the tip end-plate is added on the pressure surface of small axial fan.Numerical simulation is performed to study the influence of tip end-plate on static characteristics,noise and internal flow field of small axial fan.Finally,experiments are performed on the prototype and the best modified model,the main content and the results are as follows:(1)The 3D model is obtained by reverse design on basis of the small axial fan.The tip end-plate is added along the chordwise on the pressure surface of the prototype,six kinds of modified models with three different width and three different chordwise of tip end-plate are built.The computational domain is meshed with structure grids,the method of numerical simulation and the model for noise prediction are chosen properly.(2)Numerical simulation is performed on the modified models and the prototype.The static characteristics and the internal flow field are analyzed,the results show that: adding tip end-plate decreses the static pressure,which has negative influence on ventilation of the small axial fan.Tip end-plate can increase the speed of the air downstream,decrese the vorticity near the rotational area,which can improve the condition of the internal flow to a certain degree.(3)Numerical simulation is performed on the modified models and the prototype and the noise is analyzed,it presents that: the noise of the modified model with 2mm with of tip end-plate is 1.2 dB lower than that of the prototype on the mornitoring point in the far-field,the noise of the modified model with 4/5 chordwise of tip end-plate is 2.4 dB lower than that of the prototype on the mornitoring point in the far-field.It can be concluded that the 2mm is the best width and the 4/5 chordwise is the best length of the tip end-plate in this study.Adding tip end-plate has negative influence on decresing noise in the near-field.(4)Finally,the static characteristics experiment and the noise test are performed on the prototype and the modified model with 2mm width and 4/5 chordwise.The result of the static characteristics experiment shows that the pressure of the modified model is a little lower than that of the prototype.The result of the noise test shows that the noise of the modified model is lower than that of the prototype in the far-field.The results of the experiments agree well with the results of the numerical simulation,which illustrates that the numerical simulation is relable.