Analysis Of Flow Field And Aerodynamic Noise Of Marine Gas Turbine Air Intake System

The air intake system is an important component of the marine gas turbine,and the aerodynamic characteristics of the intake system directly affect the performance of the whole gas turbine and the noise radiation of the intake system.During the operation of the marine gas turbine,the compression and expansion of the intake flow cause the pressure fluctuation in the volute,resulting in significant aerodynamic noise.The flow field distribution and distribution of noise in the intake system under various working conditions and ambient wind speed will be different.Therefore,the study on the distribution characteristics of flow field and sound field of the intake system is of great significance for understanding the aerodynamic noise of the intake system and taking corresponding noise reduction measures.In this paper,the research object is the intake system of a marine gas turbine.The flow field and aerodynamic noise of the intake system are simulated。The specific work is as follows:1.The distribution of velocity,total pressure and vorticity of the intake system are analyzed.2.Using the joint simulation of large eddy simulation and acoustic finite element,based on Lighthill acoustic analogy and M(?)hring acoustic analogy,also considering the influence of background flow field on sound field,the aerodynamic sound sources of intake system under different working conditions and ambient wind speed is calculated,and the relationship between sound source distribution and flow field characteristics is analyzed.The sound pressure level and the acoustic directivity of inlet noise under different conditions is studied.The flow induced vibration and noise of the intake system under working condition 5 is analyzed.3.In order to reduce the total pressure loss of the intake system,this paper puts forward two improved structures of the flow channel,The flow characteristics and aerodynamic sound source distribution of the improved flow channel are analyzed.This paper studies the influence of the improved flow channel on the inlet noise of the intake system.4.This paper puts forward improvement measures from the perspective of noise transmission.The influence of different wall thickness on the flow induced vibration and noise is investigated.The influence of attaching sound-absorbing materials and spraying damping materials on the flow induced vibration and noise is studied.