Sound Vibration Analysis And Noise Reduction Of Frost-free Refrigerator

With the steady development of social economy,the increasing progress of science and technology and the rise of Internet technology,people’s consumption level and quality of life continue to improve,therefore,for the large capacity,low energy consumption,intelligent and environmentally friendly refrigerator has become the goal of most consumers.At the same time,the refrigeration mode of refrigerator products is gradually upgraded from the original direct cooling to the full air cooling frost-free refrigerator,frost-free and uniform refrigeration,which is favored by consumers.In order to make the refrigerator better meet the requirements of consumers and provide more convenient service quality,reducing the overall noise of the refrigerator is the top priority of current research.In the process of working of the refrigerator,the wind duct shell generates structural vibration noise due to the rotation of the centrifugal fan,and the airflow pulsates in the air duct.So this article in frost-free refrigerator airs duct as the research object,using ANSYS simulation software and LMS vibration test software internal flow field of air duct and duct shell structure are analyzed in numerical simulation,on this basis,based on the internal flow field in air duct exit aerodynamic noise and air duct shell structure vibration is studied,on the refrigerator overall vibration noise reduction measures put forward is of great significance.Firstly,theoretical analysis of wind duct vibration and noise of frost-free refrigerator is carried out.The basic theory and sound source type of aerodynamic noise are briefly introduced.Besides,the vibration model of wind duct shell of frost-free refrigerator is analyzed and studied,which lays a foundation for simulation analysis and calculation in the following chapters of this paper.Secondly,on the basis of theoretical analysis,the establishment of the refrigerator air duct shell 3 d model,using ANSYS/Workbench analysis software,the model of air duct shell automated grid partition,then numerical simulation analysis and calculation,so as to obtain the natural frequency of the air duct shell and the harmonic response of the air duct shell,known fan work fundamental frequency,the vibration of the air duct shell area.Through the comparative analysis of modal analysis and experimental modal harmony response analysis data,it is found that the position with the maximum vibration amplitude is the same as the actual air duct.Therefore,the position with the maximum vibration amplitude of refrigerator air duct can be summarized,which provides good data support and clear direction for reducing the vibration amplitude of air duct in the future.The preliminary preparation for vibration reduction of the duct shell is proposed below.Then,set up the inside of the duct flow field model,using the ICEM software for duct flows field model segmentation method is used to add link Interface surface mesh,will be divided into a grid into ANSYS/Fluent software,the calculation model for air duct flow field grid links,select,import and export conditions to set and fan speed sett and simulated calculation,flow field characteristics of the air duct is obtained.It also prepares the ground for the following improvement to aerodynamic noise reduction in the outlet of the air duct.Finally,based on the above theoretical and simulation results,the structure of the air duct outlet of the frost-free refrigerator was improved.It was found that after adding the muffler at the outlet,the low and medium frequency noise at the outlet was reduced compared with before.According to the vibration of the duct shell,the vibration amplitude of the duct shell is obviously reduced by adding damping material in the maximum vibration area.Appropriate muffler and damping material were selected to carry out the noise experiment of the refrigerator.Through the noise test and numerical analysis of the whole refrigerator,the consistency between the experimental test results and the finite element simulation analysis results is verified,and the reliability of the simulation analysis is confirmed,so as to finally achieve the goal of reducing the noise of the refrigerator.