內燃機引擎進氣閥道內流場之研究

A Study on the Flow Field of the Intake Port in an Internal Combustion Engine

廖俊霖(Chun-Lin Liao)

指導教授 ： 鄧治東

中原大學/工學院/機械工程研究所/碩士(2001年)

https://doi.org/10.6840/cycu200100485

摘要

在引擎設計之初進氣閥道與閥門升程的設計直接影響到引擎本身的性能與效率，並且對各項引擎性能參數有深遠的影響：如空氣流量、流量係數、流動量係數、渦漩比、滾流比。如何針對不同的設計中找出最佳化的設計，就必須要靠實驗與數值模擬兩種方式。
實驗可以量測到引擎實際的表現，但是需要相當的時間、人力及足夠的實驗設備與技術，並不是一般研究單位所能負擔，而且只可以得到局部的數據與總體概括的性能，難以對整體及細部熱流場進行探討。相對的數值模擬的優點即為可在有限的時間內得到整體的熱流場現象，且易於針對研究需要調整引擎操作條件進行預測。可是先決條件為要能得到合理正確的計算結果。所以需要由實驗結果來評估數值模擬流場之準確性，並嘗試藉數值模擬詳細結果以補償實驗量測之不足。
本文乃探討FLOWBOX引擎之進氣閥道流場。利用由美國Los Alamos國家實驗室針對模擬分析內燃機引擎熱流現象所發展的KIVA-3V計算流體力學程式模擬分析一擬穩態模型（quasi-steady model）配合RNG ｋ-ε紊流模式來分析三維之進氣閥道流場在不同的進氣閥門升程下分析各項引擎參數與實驗數值的差異性。
分析數值結果發現，在空氣流量、流量係數、流動量係數、渦漩比、滾流比各項引擎參數方面，皆與工研院提供之實驗數據定量上面相吻合，而且在流場方面也呈現定性的狀況。

關鍵字

渦漩比 ； 滾流比 ； 內燃機引擎

並列摘要

The purpose of this paper is to numerically analyze the intake port flow in an internal combustion （IC） engine. With different intake valve lift, there are difference performance and efficiency for the following engine performance parameters are presented: such as flow coefficient, discharge coefficient, swirl ratio, tumble ratio.
According to different engine design, the study of the flow fields in an I.C. engine has two ways - the experimental technique and numerical simulation. The experiment can measure some of the parameters of the engine under study, but the experimental apparatus is expensive to set up and and the resources needed for time and manpower is enormous and prohibitively high for most of the research organizations. Besides, the measurement can not measure the overall flow field occurring inside the engine. With the recent progress of computer technology, numerical analysis method and software have been wildly used in most engineering problems. For predicting and analysis the thermofluid phenomena inside the I.C. engine, computational fluid dynamic (CFD) models are becoming powerful tools. The high-speed computers have the capabilities to simulate the overall behavior of the flow field in the engine. They can also predict the performance of an engine by adjusting the engine operational parameters.
This study used the KIVA code, originally developed at the US Los Alamos National Laboratory, is one of the advanced computer programs for optimizing IC engine research to analyze the quasi-steady model with different valve-lift. The turbulence model is used the Renormalization Group (RNG) turbulance model. The calculation result will be compared with experimental data.

並列關鍵字

internal combustion engine ； swirl ratio ； tumble ratio

參考文獻

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