臺灣博碩士論文加值系統

摘要

本文探討氣膠懸浮微粒在垂直平板上受熱泳效應及布朗擴散效應時，微粒附著率之影響差異。在這兩種效應的交互作用下，對微粒附著率有相當的重要性；採用垂直平板模型，統御方程式包括質量、動量與濃度方程式，在求解過程中，採用box-method與block-elimination解聯立方程式，進而算出粒子微粒附著的速度及參數。

所獲得計算結果，發現氣膠粒子在非均勻溫度場裡，其熱泳作用及對流效應對表面的沈積速率有很大影響。同時顯示被冷卻的垂直壁面，粒子有被吸附現象，而被加熱的垂直壁面，則有驅離情形。另一方面，當粒子直徑大於0.1 時，其沈積通量會趨近常數。另外，在助流的情形下，浮力對粒子沈積速率有成正比的關係。

Abstract
The heat transfer characteristic is combination of force convection and natural convection that flow over a vertical flat plat. The purpose is study of thermophoretic, Brownian diffusion and convection combined on aerosol particle deposition. The flow field was modeled as a two dimensional, incompressible and steady-state laminar flow. The governing equations include the conservation of momentum, mass and concentration. Non-similarity analysis with the box method and block elimination was to determine the velocity, temperature and concentration fields.
The effects of thermophoresis and convection were predicted to be important for submicron particles in the flow field. Thus, this theorem is worthy of note. The results showed the particle moving behavior that it is look like blowing away from a hot surface or suction from a cold surface at a temperature gradient field. Besides, the particle deposition rate increases with the particle flux will approach to constant, when the particle diameter greater than 0.1 . The influence of buoyancy on deposition, the deposition rate was proportional to the buoyancy in aiding flow.

目錄

中文摘要 -------------------------------------------- Ⅰ
英文摘要 -------------------------------------------- Ⅱ
目錄 ------------------------------------------------ Ⅳ
表目錄 ---------------------------------------------- Ⅴ
圖目錄 ---------------------------------------------- Ⅴ
符號表 ---------------------------------------------- Ⅶ
第一章 導論
1-1 前言 ---------------------------------------- 1
1-2 文獻回顧 ------------------------------------ 2
第二章 物理模型與理論分析
2-1 物理模型 ------------------------------------ 3
2-2 基本假設 ------------------------------------ 4
2-3 統御方程式 ---------------------------------- 4
2-4 非相似轉換 ---------------------------------- 7
2-5 混合對流之無因次轉換 ------------------------ 11
2-6 微粒沈積之速率計算 -------------------------- 13
第三章 數值分析 ------------------------------------- 14
第四章 結果與討論
4-1 速度分佈 ------------------------------------ 27
4-2 溫度分佈 ------------------------------------ 28
4-3 濃度分佈 ------------------------------------ 28
4-4 粒子沈積速率 -------------------------------- 30
第五章 結論與建議
5-1 結論 ---------------------------------------- 32
5-2 建議 ---------------------------------------- 34
參考文獻 -------------------------------------------- 35
附錄A ---------------------------------------------- 53
附錄B ---------------------------------------------- 54
附錄C ---------------------------------------------- 56

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