Numerical Prediction Method And Experimental Analysis Of Aerodynamic Noise Of Marine Centrifugal Fan

For ships,the comfortable ship cabin environment is more popular.Marine centrifugal fan is one of the centrifugal fans,which is widely used in the field of ships.Marine centrifugal fans will produce aerodynamic noise and mechanical noise during the work process,of which aerodynamic noise is the main noise,accounting for about 45% of the total noise.It is of great practical significance to establish accurate and reliable noise numerical analysis methods and study the aerodynamic noise characteristics of centrifugal fans.The research focus of this article is as follows:First,the three-dimensional scanner is used to scan the solid model of the centrifugal fan,and the three-dimensional centrifugal fan model is established using reverse engineering technology.Through the solid three-dimensional reverse modeling,the three-dimensional model of the centrifugal fan is obtained.The centrifugal fan model is processed according to the actual situation,and the grid is divided to complete the pre-processing work.Secondly,the three-dimensional centrifugal fan model is numerically simulated to obtain the steadystate flow field characteristics of the centrifugal fan,and the steady-state flow field analysis and research is performed on the centrifugal fan model through the simulation results.The steady-state flow field of the centrifugal fan is used as the initial condition,and the three-dimensional centrifugal fan model is numerically simulated using CFD software to calculate the unsteady-state flow field.Then,using the unsteady flow field of the centrifugal fan as the initial condition,the broadband noise model and the acoustic simulation software Actran were used to predict the aerodynamic noise of the threedimensional centrifugal fan model.The aerodynamic noise prediction results are used to analyze the noise source and noise characteristics of the centrifugal fan to provide a basis for the subsequent noise control research.And build a centrifugal fan test stand,and measure the fan noise value.The measured and simulated values are compared and analyzed to verify the accuracy of the numerical prediction method for aerodynamic noise of marine centrifugal fans.Finally,based on the flow field simulation and sound field simulation results of the centrifugal fan,the noise reduction optimization scheme of the centrifugal fan is proposed,that is,by changing the position of the centrifugal fan impeller and the modification of the two-dimensional blade,in order to achieve the purpose of noise reduction.The numerical simulation of the optimized centrifugal fan model is conducted to verify the correctness of the optimization scheme.In summary,this paper aims at the problem that marine centrifugal fans have complex aerodynamic noise sources,and it is not easy to quickly and accurately predict the noise.Taking a certain type of marine centrifugal fan as the research object,based on the analysis of flow field characteristics,the hybrid method is used to aerodynamic noise sources Make forecasts.A set of aerodynamic noise prediction methods for marine centrifugal fans was established,and an optimized plan for centrifugal fan noise reduction was proposed.