Large eddy simulation of the flow field in centrifugal fan and numerical prediction of noise in pipe

  Objectives  In order to predict the vibration noise of centrifugal fan,

  Methods  the whole flow field is meshed by the structured grid and the fluctuating force on the impeller surface that varies with time is obtained by using the Large Eddy Simulation(LES)method. Using the rotating dipole radiation model, the noise from the pipe is predicted by the acoustic finite element method. Taking the surface dipole in the volute wall as the sound source, the noise from the wall pressure fluctuation is calculated and compared with the test results.

  Results  The results show that the flow noise from the wall is higher than that of the impeller in the low frequency band, but lower in the high frequency band and have a good agreement with the test results.

  Conclusions  The prediction methods for impeller noise and volute wall pressure fluctuation noise can meet the engineering application requirements.