Equation of Continuity for Species

流体传质方程

Equation of Continuity for Species $ \alpha$ in terms of $ \pmb j_\alpha$

控制方程表达通式:


1.直角坐标系($ x, y, z $)

直角坐标系Cartesian coordinates ($\textit { x,y,z }$): NO.
$\rho \left (\dfrac {\partial w_\alpha}{\partial t}+ v_x \dfrac {\partial w_\alpha}{\partial x} +v_y \dfrac {\partial w_\alpha}{\partial y} + v_z \dfrac {\partial w_\alpha}{\partial z}\right) = - \left [\dfrac {\partial j_{\alpha x}}{\partial x} +\dfrac {\partial j_{\alpha y}}{\partial y}+\dfrac {\partial j_{\alpha z}}{\partial z}\right] + r_\alpha $ 1-1

2.圆柱坐标系($r,\theta, z$)

圆柱坐标系Cylindrical coordinates coordinates ($\textit {r, $\theta$, z }$): NO.
$\rho \left (\dfrac {\partial w_\alpha}{\partial t}+ v_r \dfrac {\partial w_\alpha}{\partial r} +\dfrac {v_\theta}{r} \dfrac {\partial w_\alpha}{\partial \theta} + v_z \dfrac {\partial w_\alpha}{\partial z}\right) = - \left [\dfrac {1}{r} \dfrac {\partial}{\partial r} (r j_{\alpha r}) + \dfrac {1}{r} \dfrac {\partial j_{\alpha \theta}}{\partial \theta}+\dfrac {\partial j_{\alpha z}}{\partial z}\right] + r_\alpha$ 2-1

3.球坐标系($r, \theta, \phi $)

球坐标系Spherical coordinates($\textit {r, $\theta$, $\phi$ }$): NO.
$\rho \left (\dfrac {\partial w_\alpha}{\partial t}+ v_r \dfrac {\partial w_\alpha}{\partial r} +\dfrac {v_\theta}{r} \dfrac {\partial w_\alpha}{\partial \theta} + \dfrac {v_\phi}{rsin\theta} \dfrac {\partial w_\alpha}{\partial \phi}\right) = \left [\dfrac {1}{r^2} \dfrac {\partial}{\partial r} (r^2 j_{\alpha r}) + \dfrac {1}{r sin\theta} \dfrac {\partial}{\partial \theta}(j_{\alpha \theta} sin\theta)+ \dfrac {1}{rsin\theta} \dfrac {\partial j_{\alpha \phi}}{\partial \phi}\right] + r_\alpha $ 3-1

注:如果密度被浓度代替。都要做相应的替换

质量浓度 $\rho$ $w_\alpha$ $\pmb j_\alpha$ $\pmb v$ $r_\alpha $
摩尔浓度 $c$ $x_\alpha$ $\pmb J_\alpha^*$ $\pmb v^*$ $R_\alpha-x_\alpha \sum\limits_{\beta=1}^{N}R_\beta $

Equation of Continuity for Species A with Constant $\rho \mathscr{D}_{AB}$ in terms of $w_A$

控制方程表达通式:


1.直角坐标系($ x, y, z $)

直角坐标系Cartesian coordinates ($\textit { x,y,z }$): NO.
$\rho \left (\dfrac {\partial w_A}{\partial t}+ v_x \dfrac {\partial w_A}{\partial x} +v_y \dfrac {\partial w_A}{\partial y} + v_z \dfrac {\partial w_A}{\partial z}\right) = \rho \mathscr{D}_{AB} \left [\dfrac {\partial^2 w_A}{\partial x^2} +\dfrac {\partial ^2 w_A}{\partial y^2}+\dfrac {\partial ^2 w_A}{\partial z^2}\right] +r_A $ 1-1

2.圆柱坐标系($r,\theta, z$)

圆柱坐标系Cylindrical coordinates coordinates ($\textit {r, $\theta$, z }$): NO.
$\rho \hat {C}_p \left (\dfrac {\partial w_A}{\partial t}+ v_r \dfrac {\partial w_A}{\partial r} +\dfrac {v_\theta}{r} \dfrac {\partial w_A}{\partial \theta} + v_z \dfrac {\partial w_A}{\partial z}\right) = \rho \mathscr{D}_{AB}\left [\dfrac {1}{r} \dfrac {\partial}{\partial r} \left(r \dfrac{\partial w_A}{\partial r}\right) + \dfrac {1}{r^2} \dfrac {\partial^2 w_A}{\partial \theta^2}+\dfrac {\partial^2 w_A}{\partial z^2}\right] +r_A $ 2-1

3.球坐标系($r, \theta, \phi $)

球坐标系Spherical coordinates($\textit {r, $\theta$, $\phi$ }$): NO.
$\rho \hat {C}_p \left (\dfrac {\partial w_A}{\partial t}+ v_r \dfrac {\partial w_A}{\partial r} +\dfrac {v_\theta}{r} \dfrac {\partial w_A}{\partial \theta} + \dfrac {v_\phi}{rsin\theta} \dfrac {\partial w_A}{\partial \phi}\right) =\rho \mathscr{D}_{AB} \left [\dfrac {1}{r^2} \dfrac {\partial}{\partial r} \left(r^2 \dfrac {\partial w_A}{\partial r} \right) + \dfrac {1}{r^2 sin\theta} \dfrac {\partial}{\partial \theta} \left(sin\theta \dfrac {\partial w_A}{\partial \theta}\right)+ \dfrac {1}{r^2 sin^2\theta} \dfrac {\partial^2 w_A}{\partial \phi^2}\right] +r_A $ 3-1


参考文献

  1. R. Byron Bird, Warren E. stewart, Edwin N. Lightfoot. Transport phenomena:Revised second edition John Wiely &Sons, Inc.
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