A Numerical Simulation And Flow Noise Analysis Of Intake Air Duct And Blower Of Automobile Air Conditioner

In recent years,with the development and progress of society,cars have gradually become an indispensable means of transportation,the comfort requirement of car is also getting higher and higher,and car noise has gradually attracted attention.Enhancing the airtightness of the body can resist outside noise of the car,and the air conditioning noise has become the main source of noise inside car.This article takes the air-conditioning intake channel and blower of a car as the research object,the aerodynamic noise of the fan system is studied through the combination of numerical simulation and experiment.The details are as follows:1.Research on flow field characteristics of fan system.A three-dimensional physical model of the intake system and the overall system of the blower is established by using CATIA software.Based on STAR-CCM+ software for numerical simulation and analysis of fan system in different speed,and determined the relationship between the fan's outlet speed,flow,pressure drop and blower speed,the comparative analysis of the numerical simulation results and the experimental results verifies the accuracy of the numerical simulation analysis of the fan system flow field.2.Perform steady-state and transient analysis of the sound field of the fan system.The distribution of the internal noise source is analyzed by the broadband noise model and the pressure pulsation of the internal monitoring point,through the sound pressure calculation of the external monitoring points M1,M2 and M3,the total sound pressure level values at different monitoring points are analyzed.Comparing the calculation results with the experimental test data,the correctness of the sound field simulation is verified.3.Analysis of factors affecting the sound field of the fan system and structural improvement.The results of the study show that the air filter plays a role in reducing the aerodynamic noise with a uniform flow field.The air filter bracket increases the noise of the fan system,the fan speed has an effect on the system sound field,and the study gives an estimation method of the sound pressure level of the aerodynamic noise of the fan at different speeds.Two types of air filter bracket structures are proposed,and research shows that the double-blade guide bracket has a significant effect on reducing system noise.