慣性效應影響微粒沉積率之研究

A Study of Inertial Effect on Particle Deposition Rates

涂育麟(Yu-Lin Tu)

指導教授 ： 蔡瑞益

中原大學/工學院/機械工程研究所/碩士(2001年)

https://doi.org/10.6840/cycu200100278

摘要

本文探討氣懸浮微粒在楔形流中受慣性和布朗擴散效應作用時，微粒附著率所產生之影響差異。這兩種傳輸機制的交互作用，對微粒附著率具有相當重要性；而控制慣性效應之無因次參數定義為修正史托克數(Stkx)。本文採二維楔形流模型，制御方程式包括動量及濃度場方程式，在求解的過程中採H. B. keller [22] 所提出(Box method)解動量及濃度場方程式，進而推算出微粒附著速度或附著參數。
在楔形流物理模型下探討擴散效應下慣性效應存在與不存在微粒附著率所產生之差異；我們將發現在慣性及擴散效應影響下，當微粒粒徑很小時，微粒附著率乃受布朗擴散效應支配，但當微粒粒徑增大時擴散效應趨減而慣性效應之影響趨增；且面對不同角度之楔形板塊，微粒受慣性效應影響情形亦不相同。

關鍵字

相似分析法 ； 楔形流 ； 慣性效應

並列摘要

Combined effects of inertial and Brownian diffusion on particle deposition onto wedges are reported. The two effects are important mechanisms for particle deposition. We introduced the modified Stokes number, Stkx , as the dominate parameter to the inertial effect. In this study, the flow was modeled as a two-dimension laminar flow. The governing equations include the conservation of mass momentum and particle species. Box method was used to solve the equations and obtained flow field and particle concentration. Then we also calculated the particle deposition velocity, that is a function of Stkx .
In this study, we die a comparison of particle deposition rates from the inertia effect exist or not in the wedge flow under Brownian diffusion effects. We found that particle deposition rates are controlled by Brownian diffusion effect for ultra-small particle sizes. However, when the particle size increases, the inertial effect becomes important and Brownian diffusion effect maybe negligible. Also, the inertial effects on particle deposition rates for different wedge angles are examined.

並列關鍵字

inertial ； Wedge ； similarity analysis

參考文獻

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