具表面化學反應垂直通道之熱流場及濃度場分析

Abstract

本文利用數值分析來探討垂直通道內具邊界化學反應的各種特性。整個機構包括自 然對流、強制對流、濃度質傳效應及邊界化學反應。經由傳遞的過程中，研究藥液和邊 界的接觸反應區域所伴隨的均勻化學反應，然而因考慮反應時濃度的消耗，故使用一階 的阿瑞尼亞化學反應式來模擬。同時以窩度──旋度函數解析法 (Vorticity-Stream function formulation)處理動量方程式，其中質量傳遞方程式、 渦旋傳遞方程式及能量方程式以交替向隱蔽法(A.D.I method)求解，而修正流線方程式 則以連續超鬆弛法(S.O.R method)來求解。由結果可發現，雷諾數越高、藥液進口濃度 越高、長度比較小、單一入口及紅外線加熱強度較強會導致邊界化學反應速率較快；而 雷諾數越高、進口藥液濃度越低、長寬比較大及雙入口對於邊界表面化學反應會較均勻 。

A numerical analysis is performed in this study to examine the characteristics of surface chemical reaction in vertical channel. Mechanisms of free convection, forced convection, mass transter and surface chemical reaction. The surface section is considered as homogenous reactions and the first order Arrhenius is applied to simulate the reaction rate. The 2-D Navier-Stokes equations are expressed in terms of stream function-vorticity formulation. The mass trasfer equation, the vorticity equation and encrgy equation are solved by an A.D.I techniuqe. The Gaussian S.O.R technique is utilized to slove the modified stream function equation. The results show that the distribution of temperature, concentration and influenced by the size of the inlet, the flow rate, inlet condition and inlet velocity of the fluid.