The Analysis and Simulation of Mufflers in Exhaust System

• Main Author: 張峻瑋
• Other Authors: 許華倚
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/vy52n2

碩士 === 國立臺北科技大學 === 機電整合研究所 === 101 === The main objective of this work is to investigate the emissions of gas flowing through the engine exhausting system, the noise and the impulse noise caused by the muffler, and the flow simulation from the transmission losses. It is also important to explore the muffler with porous media using different porosities and the interaction between muffler noises. The CFD tool has been used here to simulate the exhausting system and the flow field of the muffler. This is a three-dimensional incompressible steady-state flow which is solved by the Navier-Stokes equations. This turbulent flow is described as the RANS state of turbulence model. The Standard k-ε model is applied to solve this turbulent flow. The aerodynamically caused noise model used here are: FW-H model and the BNS model which separately show the flow field and the sound pressure distribution of the flow in unsteady state and steady state. First, the computer-aided design drawing software has been used to draw the internal flow of the muffler, constructing the grid, setting equivalent boundary conditions and appropriate numerical methods, and finally the numerical results will be obtained to compare the results with other studies. The result will be finally exported as post-processing image to do the related research.