Theoretical And Experimental Study On Aerodynamic Quality Of Dissipative Silencer

Based on the present condition of noise pollution in China, it is summarized to the development of the control of noise pollution, especial that of industry. Much attention has been paid to the study of muffler, which is the main device to eliminate aerodynamic noise. The development process and the present.condition of research methods about mufflers in China and abroad are introduced briefly in the paper. Based on the achievement in the past, the research is carried to the aerodynamic quality of dissipative silencer from theory and experiment. At the theoretical aspect, theoretical analysis and numerical simulation are carried to the aerodynamic quality (dynamic resistance loss) of mufflers by the analysis of the internal flow field in mufflers. Computational fluid dynamics (CFD) method is used to analyze the air flow condition in mufflers. Then finite element analysis software are used to numerical simulation to get the relation among the velocity of air, degree of roughness of mufflers' internal wall(changing with the punching rate) and dynamic resistance loss. At the experimental aspect, according to the national standard of the People' s Republic of China, muffler model, experimental situation and steps are designed to get the test data about the relation among the air velocity, the punching rate of guard board, dynamic resistance loss and noise elimination. The aerodynamic quality of dissipative silencer is summarized through the data from theory and experiment. At last, numerical modal analysis is applied to mufflers and gets natural vibration frequencies and natural modes. Study the relation between the natural modes and noise signal to perfect the design the research of dissipative silencer.