單缸四行程引擎排氣尾流音之模擬與量測分析

Simulation and Experimental Analysis on the Exhaust Noise of a Four Stroke Single Cylinder Engine

陳鼎文(Ding-Wen Chen)

指導教授 ： 蔡國隆

國立臺北科技大學/機電學院/車輛工程系所/碩士(2006年)

https://doi.org/10.6841/NTUT.2006.00079

摘要

本研究係以引擎模擬程式ESP（Engine simulation program）運用在PGO125c.c.機車引擎的排氣噪音模擬，先以實際機車實驗之結果與模擬結果作對照與校正，等確定其他變數後，再以CFD-RC軟體建立三維的消音器模式，將其進行計算，以獲得不同外型尺寸設計消音器尾管出口處在不同轉速下的流速變化，最後再套入理論公式並以Matlab作排氣噪音值之運算。在實驗方面，使用一台PGO125c.c.機車裝上與模擬幾何形狀一樣之消音器，量測其不同轉速下的排氣尾流音之頻譜，並與模擬之結果做其比較。期望經由本研究能更確切瞭解引擎運轉狀況與排氣噪音間之關係，讓後續汽車噪音的研發更精確、省時與節省成本，進而達到大都會區居民生活環境品質的提高。

關鍵字

引擎模擬 ； 排氣噪音 ； 消音器

並列摘要

This research uses the ESP (engine simulation program) to simulate a 125c.c.engine. The simulated engine-torque was compared with the experimental data to a consistence condition by tuning the parameters and constants. Thereafter, three dimensional muffler models (CFD-RC) were set up for modeling the behavior of simple geometry muffler. By using the information from ESP simulation, both the pressure and velocity field at the inlet of the muffler were used and the history of tailpipe velocity was obtained in turn. A sound pressure level calculation then can be derived from theoretical formula and tailpipe noise can obtain. In this manuscript, the measurements of tailpipe noise spectrum at different engine speeds were compare with the results of simulation. The purpose of this study is to improve understanding on the engine exhaust noise in different speeds, the research and development of the follow-up automobile noise can be predicted more accurately, and it can reduce time and cost of design, and then reach the improvement of resident's living environment quality in the district of city.

並列關鍵字

Engine simulation ； exhaust noise ； muffler

參考文獻

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