Study On The Aerodynamic Performance And Noise Of The Centrifugal Fan For Vacuum Cleaners

The centrifugal fan is a kind of fluid machinery which is widely used in industrial production and daily life.In this paper,a high-speed centrifugal fan for vacuum cleaner is taken as the research object.The aerodynamic performance and aerodynamic noise of fan are studied by numerical simulation and experimental verification.The influence of some key design parameters is explored,and efficiency optimization and noise reduction research are carried out.First,the mixed plane method and sliding mesh are used to simulate the original fan respectively.The calculation results are compared with the experimental results to verify the feasibility of the method.Through the detailed analysis of the characteristics inside the fan,including axial vortex,secondary flow and separation flow,understanding of the complex flow phenomenon is enhanced.Next,the influence of blade inlet angle?₁,outlet angle?₂ and arc radius r₁ of the blend on fan aerodynamic performance is investigated and the rules are summarized.Then,on account of geometric limitations of the double arc blade,the three-order Bessel curve is provided to express the profile.By parametric modeling Bessel curve,deriving the mathematical model of the optimization problem,an optimized fan of high efficiency is obtained combined with experimental design,response surface method and numerical optimization.Finally,a prototype of optimized fan is made to be tested and the results show that the requirement of the higher peak efficiency is achieved.For the noise reduction research,the acoustic analogy method is used to simulate the acoustic field of the fan and calculation results are compared with test results to prove the feasibility of the method.According to the distribution of the sound source intensity,the main source position is determined,and the noise reduction is carried out aimed at these positions.Comparing fans with different blade number,it is found that increasing blade number can effectively reduce the rotation noise,also has certain inhibitory effect on broadband.However,more blade number reduces the operating efficiency.In addition,effect of blade cutting on the fan performance is studied.The results show it can greatly reduce noise of first order harmonic frequency and broadband noise nearby on the premise of unchanged operating efficiency,and it has a good prospect of application.