臺灣博碩士論文加值系統

紊流燃燒的過程中，由於流場的不規則性，使得火焰面形狀產生皺折，火焰面的交錯亦使火焰與火焰間發生許多不同形式的交互作用，由於此過程複雜而高度非線性，故須加以簡化，以探討特定機制的效應，因此本文以數值方法探討球形預混火焰的上游交互作用。
影響反應速率的機制首先須考慮火焰拉伸率的效應。火焰拉伸率來自於火焰面上的切線速度梯度，以及曲率與法線速度造成的面積改變，在此希望討論的是後者所造成的交互作用。本論文探討球形火焰面向內傳播的漸縮過程中，曲率半徑漸小，形成拉伸率逐漸增加而影響反應速率；其次，當球面火焰半徑極小時，預熱區相接觸，由於溫度與各成份的擴散速率不同，而產生的上游交互作用，也會改變反應速率，而產生微爆或不完全燃燒。
根據從前對於兩平面預混火焰間上游交互作用所得的結果可知，當有效路易數（effective Lewis number）大於1，反應速率會因上游交互作用而增加，反之，當有效路易數小於1時，反應速率會減少。與平面預混火焰不同的是，球形預混火焰考慮火焰拉伸率對反應速率的效應。結果顯示，在球形預混火焰的上游交互作用中，反應速率的增加（Le > 1）或減緩（Le < 1），會因負的火焰拉伸率影響而更加顯著。

Upstream interaction of a spherically premixed flame is investigated numerically in this work. According to the results of upstream interactions between two plane premixed flames in the previous paper, the burning rate for Le > 1 is accelerated during upstream interaction, whereas the burning rate is decelerated for Le < 1. Unlike the plane premixed flame, the dependence of burning rate on the flame stretch is involved for spherically premixed flames. The results reveal that the acceleration (Le > 1) and the deceleration (Le < 1) of burning rate are enhanced for upstream interactions of spherically premixed flames due to the influence of flame stretch.

摘要 i
目錄 ii
圖表目錄 iii
符號說明 iv
第一章 緒論……………………… 1
1.1前言………………………… 1
1.2文獻回顧…………………… 2
第二章 數學模式分析…………… 6
2.1問題描述…………………… 6
2.2基本假設…………………… 6
2.3數學模式…………………… 7
2.3.1統御方程式…………… 7
2.3.2起始條件……………… 8
2.3.3邊界條件……………… 8
2.4數值方法…………………… 9
第三章 結果與討論……………… 11
3.1富油火焰…………………… 11
3.2貧油火焰…………………… 13
3.3當量燃燒火焰……………… 14
第四章 結論……………………… 16
參考文獻………………………… 17

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