臺灣博碩士論文加值系統

摘 要
本文主要是以實驗方法探討高壓環境對同質衝擊噴流衝擊霧化性能之影響。實驗所使用的注油器皆自行製造，注油器孔口直徑為0.5mm，衝擊角度固定為900，以淨化處理過的純水為測試液體。高壓測試艙所能調整的最大壓力為8.5kg/cm2，並利用影像處理分析系統及Insitec雷射繞射粒徑分析儀對霧化特性作定性的觀察及定量的量測。
實驗結果顯示，在常壓下純水液膜型態隨噴流速度的增加分為四種模式：(1)封閉液緣與週期性掉落模式；(2)封閉液緣與散射液滴模式；(3)開放液緣模式；(4)完全發展模式。在高壓下(8.5kg/cm2以下)，純水的液膜型態隨噴流速度增加也出現如常壓下所定義的四種模式，但其液膜由封閉液緣模式轉變為開放液緣模式會在較低的流速下發生，也就是較高的環境壓力會使液膜較易由封閉液緣轉變為開放液緣模式。
在封閉液緣模式下，不論是在常壓環境或是高壓環境，液膜的長度與寬度皆隨著噴流速度的增加而遞增，且其長寬比維持在2左右，即液膜形狀不隨噴流速度改變而改變，但其大小會隨噴流速度增加而增加；在開放液緣模式下，不論是在常壓環境或是高壓環境，隨著噴流速度的增加，液膜的長度漸減，而液膜的寬度仍遞增。
不論是在常壓環境或是高壓環境，衝擊霧化液滴平均粒徑皆有隨著噴流速度增加而減小的趨勢；在相同的噴流速度下，較高的環境壓力所得的霧化液滴平均粒徑會較小。

Abstract
The objective of the study is mainly to investigate the influence of the high pressure environment on the atomization of like-doublet impinging-jet injectors by using photographic imaging technology and laser diffraction particle sizing device. The injector diameter is selected as 0.5mm and the impingement angle is maintained at 900. The working fluid is pure water, and the maximum pressure inside the high pressure chamber is 8.5kg/cm2.
The results show that under normal pressure environment, with increasing jet velocity there are four spray patterns formed by impinging jets. They are defined as (1)close rim with periodic drops,(2)close rim with shedding drops,(3)open rim with shedding drops and (4)fully developed. Under high pressure environment(below 8.5kg/cm2), the four spray patterns defined above also show up with increasing jet velocity. But the transformation of liquid sheet from "close rim mode" to "open rim mode" will occur at lower jet velocity.
At close rim mode, the length and width of liquid sheet both increase with increasing jet velocity no matter it is under normal or high pressure environment, and the length-to-width ratio is maintained at 2；that is, the shape of liquid sheet does not change with the jet velocity, but the size will increase with the increase of jet velocity. At open rim mode, no matter it is under normal or high pressure environment, the width of liquid sheet still increases with the increase of jet velocity, but the length decreases.
No matter it is under normal or high pressure environment, with the measurement of INSITEC particle sizer, the mean drop size of atomized droplets decreases with the increase of jet velocity. At the same jet velocity, the mean drop size of atomized droplets is smaller when the environment pressure is higher.

目 錄
授權書
簽署人須知
摘要
英文摘要
誌謝
目錄………………………………………………………………………….Ⅰ
圖目錄……………………………………………………………………….Ⅲ
符號說明…………………………………………………………………….Ⅴ
第一章 緒論………………………………………………………………...1
1-1 簡介……………………………………………………………. …1
1-2 衝擊式注油器簡介……………………………………………….2
1-3 文獻回顧………………………………………………………….2
1-3-1 流體的碎裂過程……………………………………………..2
1-3-2 壓力式渦漩霧化器霧化特性之研究………………………..4
1-3-3 衝擊式注油器之相關研究…………………………………..4
1-4 研究目的………………………………………………………….8
第二章 實驗設備及儀器…………………………………………………...9
2-1 高壓測試艙………………………………………………………..9
2-2 衝擊式注油器……………………………………………………..9
2-3 液體供應系統……………………………………………………10
2-4 影像擷取及分析系統……………………………………………10
2-5 平均粒徑分析系統………………………………………………11
第三章 實驗步驟及方法………………………………………………….13
3-1 流量的量測及校正………………………………………………13
3-2 高壓環境下液膜型態的觀察及攝影……………………………13
3-3 Insitec雷射粒徑分析儀的量測………………………………….14
第四章 結果與討論………………………………………………………...16
4-1 Insitec與Malvern量測比較……………………….……………16
4-2 液膜的型態………………………………………………………18
4-2-1 常壓下純水的液膜型態……………………………………19
4-2-2 高壓下純水的液膜型態……………………………………19
4-3 液膜的幾何形狀…………………………………………………20
4-3-1 常壓下純水液膜的幾何形狀……………..…………………20
4-3-2 高壓下純水液膜的幾何形狀………………………….…….21
4-4 霧化液滴平均粒徑的探討……………………………………...21
4-4-1 常壓下衝擊噴流平均粒徑量測…………………………..........22
4-4-2 高壓下衝擊噴流平均粒徑量測…………………………..........22
4-4-3 實驗誤差檢討……………………………………………..........23
第五章 結論……………………………………………………………….25
第六章 未來工作………………………………………………………….27
參考文獻…………………………………………………………………….28
自述………………………………………………………………………….72
著作權聲明………………………………………………………………….73

參考文獻
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