広告
・運動量収支式の離散化
x, y, z軸方向の無次元化した運動量収支式は次式となります。
\[
\phi_x=\frac{\partial V_x}{\partial\tau}
+V_x\frac{\partial V_x}{\partial X}
+V_y\frac{\partial V_x}{\partial Y}
+V_z\frac{\partial V_x}{\partial Z}
-\frac{\partial\sigma^*_{xx}}{\partial X}
-\frac{\partial\sigma^*_{yx}}{\partial Y}
-\frac{\partial\sigma^*_{zx}}{\partial Z}
-g_x^*=0
\]
\[
\phi_y=\frac{\partial V_y}{\partial\tau}
+V_x\frac{\partial V_y}{\partial X}
+V_y\frac{\partial V_y}{\partial Y}
+V_z\frac{\partial V_y}{\partial Z}
-\frac{\partial\sigma^*_{xy}}{\partial X}
-\frac{\partial\sigma^*_{yy}}{\partial Y}
-\frac{\partial\sigma^*_{zy}}{\partial Z}
-g_y^*=0
\]
\[
\phi_z=\frac{\partial V_z}{\partial\tau}
+V_x\frac{\partial V_z}{\partial X}
+V_y\frac{\partial V_z}{\partial Y}
+V_z\frac{\partial V_z}{\partial Z}
-\frac{\partial\sigma^*_{xz}}{\partial X}
-\frac{\partial\sigma^*_{yz}}{\partial Y}
-\frac{\partial\sigma^*_{zz}}{\partial Z}
-g_z^*=0
\]
内挿関数Niを重み関数に使用すると離散化式は次式となります。
\[
\int_V
\begin{bmatrix}
N_1\\N_2\\N_3\\N_4
\end{bmatrix}
\phi_i\,dV
=
\int_V
\begin{bmatrix}
0\\0\\0\\0
\end{bmatrix}
dV
=
\begin{bmatrix}
0\\0\\0\\0
\end{bmatrix}
\]
速度、圧力は、内挿関数Niを用いてそれぞれ次式で表されます。
\[
\begin{aligned}
V_x&={}N_1V_{x,1}+N_2V_{x,2}+N_3V_{x,3}+N_4V_{x,4}
=
\begin{bmatrix}N_1&N_2&N_3&N_4\end{bmatrix}
\begin{bmatrix}V_{x,1}\\V_{x,2}\\V_{x,3}\\V_{x,4}\end{bmatrix}
=[N]\{V_x\}\\[6pt]
V_y&={}N_1V_{y,1}+N_2V_{y,2}+N_3V_{y,3}+N_4V_{y,4}\\[6pt]
V_z&={}N_1V_{z,1}+N_2V_{z,2}+N_3V_{z,3}+N_4V_{z,4}\\[6pt]
P&={}N_1P_{z,1}+N_2P_{z,2}+N_3P_{z,3}+N_4P_{z,4}
\end{aligned}
\]
i軸方向の離散化式は、次式となります。
\[
\begin{aligned}
&\int_V
\begin{bmatrix}N_1\\N_2\\N_3\\N_4\end{bmatrix}
\phi_i\,dV\\[6pt]
&={}\int_V
\begin{bmatrix}N_1\\N_2\\N_3\\N_4\end{bmatrix}
\left(
\frac{\partial V_i}{\partial\tau}
+V_x\frac{\partial V_i}{\partial X}
+V_y\frac{\partial V_i}{\partial Y}
+V_z\frac{\partial V_i}{\partial Z}
-\frac{\partial\sigma^*_{xi}}{\partial X}
-\frac{\partial\sigma^*_{yi}}{\partial Y}
-\frac{\partial\sigma^*_{zi}}{\partial Z}
-g_i^*
\right)dV
\end{aligned}
\]
展開すると
\[
\begin{aligned}
&={}\int_V
\begin{bmatrix}N_1\\N_2\\N_3\\N_4\end{bmatrix}
\frac{\partial V_i}{\partial\tau}\,dV\\[6pt]
&+V_x\int_V
\begin{bmatrix}N_1\\N_2\\N_3\\N_4\end{bmatrix}
\frac{\partial V_i}{\partial X}\,dV
+V_y\int_V
\begin{bmatrix}N_1\\N_2\\N_3\\N_4\end{bmatrix}
\frac{\partial V_i}{\partial Y}\,dV
+V_z\int_V
\begin{bmatrix}N_1\\N_2\\N_3\\N_4\end{bmatrix}
\frac{\partial V_i}{\partial Z}\,dV\\[6pt]
&-\int_V
\begin{bmatrix}N_1\\N_2\\N_3\\N_4\end{bmatrix}
\frac{\partial\sigma^*_{xi}}{\partial X}\,dV
-\int_V
\begin{bmatrix}N_1\\N_2\\N_3\\N_4\end{bmatrix}
\frac{\partial\sigma^*_{yi}}{\partial Y}\,dV
-\int_V
\begin{bmatrix}N_1\\N_2\\N_3\\N_4\end{bmatrix}
\frac{\partial\sigma^*_{zi}}{\partial Z}\,dV\\[6pt]
&-\int_V
\begin{bmatrix}N_1\\N_2\\N_3\\N_4\end{bmatrix}
g_i^*\,dV
\end{aligned}
\]
\[
\begin{aligned}
&={}\int_V[N]^T\frac{\partial V_i}{\partial\tau}dV\\[6pt]
&+V_x\int_V[N]^T\frac{\partial V_i}{\partial X}dV
+V_y\int_V[N]^T\frac{\partial V_i}{\partial Y}dV
+V_z\int_V[N]^T\frac{\partial V_i}{\partial Z}dV\\[6pt]
&-\int_V[N]^T\frac{\partial\sigma^*_{xi}}{\partial X}dV
-\int_V[N]^T\frac{\partial\sigma^*_{yi}}{\partial Y}dV
-\int_V[N]^T\frac{\partial\sigma^*_{zi}}{\partial Z}dV\\[6pt]
&-\int_V[N]^Tg_i^*dV
\end{aligned}
\]
グリーン・ガウスの定理より
\[
\begin{aligned}
&={}\int_V[N]^T
\frac{[N](\{V_i\}^{\tau+\Delta\tau}-\{V_i\}^{\tau})}{\Delta\tau}dV\\[6pt]
&+V_x\int_V[N]^T\frac{\partial[N]\{V_i\}}{\partial X}dV
+V_y\int_V[N]^T\frac{\partial[N]\{V_i\}}{\partial Y}dV
+V_z\int_V[N]^T\frac{\partial[N]\{V_i\}}{\partial Z}dV\\[6pt]
&-\int_S[N]^T\sigma^*_{xi}n_xdS
+\int_V\left[\frac{\partial N}{\partial X}\right]^T\sigma^*_{xi}dV\\[6pt]
&-\int_S[N]^T\sigma^*_{yi}n_ydS
+\int_V\left[\frac{\partial N}{\partial Y}\right]^T\sigma^*_{yi}dV\\[6pt]
&-\int_S[N]^T\sigma^*_{zi}n_zdS
+\int_V\left[\frac{\partial N}{\partial Z}\right]^T\sigma^*_{zi}dV\\[6pt]
&-\int_V[N]^Tg_i^*dV
\end{aligned}
\]
界面に作用する応力をまとめると
\[
\begin{aligned}
&={}\int_V[N]^T[N]dV\,
\frac{\{V_i\}^{\tau+\Delta\tau}-\{V_i\}^{\tau}}{\Delta\tau}\\[6pt]
&+V_x\int_V[N]^T\left[\frac{\partial N}{\partial X}\right]dV\{V_i\}
+V_y\int_V[N]^T\left[\frac{\partial N}{\partial Y}\right]dV\{V_i\}
+V_z\int_V[N]^T\left[\frac{\partial N}{\partial Z}\right]dV\{V_i\}\\[6pt]
&+\int_V\left[\frac{\partial N}{\partial X}\right]^T\sigma^*_{xi}dV
+\int_V\left[\frac{\partial N}{\partial Y}\right]^T\sigma^*_{yi}dV
+\int_V\left[\frac{\partial N}{\partial Z}\right]^T\sigma^*_{zi}dV\\[6pt]
&-\int_S[N]^T\left(\sigma^*_{xi}n_x+\sigma^*_{yi}n_y+\sigma^*_{zi}n_z\right)dS\\[6pt]
&-\int_V[N]^Tg_i^*dV
\end{aligned}
\]
応力を展開して
\[
\begin{aligned}
&={}\int_V[N]^T[N]dV\,
\frac{\{V_i\}^{\tau+\Delta\tau}-\{V_i\}^{\tau}}{\Delta\tau}\\[6pt]
&+V_x\int_V[N]^T\left[\frac{\partial N}{\partial X}\right]dV\{V_i\}
+V_y\int_V[N]^T\left[\frac{\partial N}{\partial Y}\right]dV\{V_i\}
+V_z\int_V[N]^T\left[\frac{\partial N}{\partial Z}\right]dV\{V_i\}\\[6pt]
&+\int_V\left[\frac{\partial N}{\partial X}\right]^T
\left\{-\delta_{xi}P+\frac{1}{Re}\left(\frac{\partial V_i}{\partial X}+\frac{\partial V_x}{\partial X_i}\right)\right\}dV\\[6pt]
&+\int_V\left[\frac{\partial N}{\partial Y}\right]^T
\left\{-\delta_{yi}P+\frac{1}{Re}\left(\frac{\partial V_i}{\partial Y}+\frac{\partial V_y}{\partial X_i}\right)\right\}dV\\[6pt]
&+\int_V\left[\frac{\partial N}{\partial Z}\right]^T
\left\{-\delta_{zi}P+\frac{1}{Re}\left(\frac{\partial V_i}{\partial Z}+\frac{\partial V_z}{\partial X_i}\right)\right\}dV\\[6pt]
&-\frac{2K^*}{We}n_i\int_S[N]^T dS\\[6pt]
&-\int_V[N]^Tg_i^*dV
\end{aligned}
\]
\[
\begin{aligned}
&={}\int_V[N]^T[N]dV\,
\frac{\{V_i\}^{\tau+\Delta\tau}-\{V_i\}^{\tau}}{\Delta\tau}\\[6pt]
&+V_x\int_V[N]^T\left[\frac{\partial N}{\partial X}\right]dV\{V_i\}
+V_y\int_V[N]^T\left[\frac{\partial N}{\partial Y}\right]dV\{V_i\}
+V_z\int_V[N]^T\left[\frac{\partial N}{\partial Z}\right]dV\{V_i\}\\[6pt]
&+\int_V\left[\frac{\partial N}{\partial X}\right]^T
\left\{-\delta_{xi}P+\frac{1}{Re}\left(\frac{\partial V_i}{\partial X}+\frac{\partial V_x}{\partial X_i}\right)\right\}dV\\[6pt]
&+\int_V\left[\frac{\partial N}{\partial Y}\right]^T
\left\{-\delta_{yi}P+\frac{1}{Re}\left(\frac{\partial V_i}{\partial Y}+\frac{\partial V_y}{\partial X_i}\right)\right\}dV\\[6pt]
&+\int_V\left[\frac{\partial N}{\partial Z}\right]^T
\left\{-\delta_{zi}P+\frac{1}{Re}\left(\frac{\partial V_i}{\partial Z}+\frac{\partial V_z}{\partial X_i}\right)\right\}dV\\[6pt]
&-\frac{2K^*}{We}n_i\int_S[N]^T dS\\[6pt]
&-\int_V[N]^Tg_i^*dV
\end{aligned}
\]
項ごとに分解して
\[
\begin{aligned}
&={}\int_V[N]^T[N]dV\,
\frac{\{V_i\}^{\tau+\Delta\tau}-\{V_i\}^{\tau}}{\Delta\tau}\\[6pt]
&+V_x\int_V[N]^T\left[\frac{\partial N}{\partial X}\right]dV\{V_i\}
+V_y\int_V[N]^T\left[\frac{\partial N}{\partial Y}\right]dV\{V_i\}
+V_z\int_V[N]^T\left[\frac{\partial N}{\partial Z}\right]dV\{V_i\}\\[6pt]
&+\frac1{Re}\int_V\left[\frac{\partial N}{\partial X}\right]^T\frac{\partial V_i}{\partial X}dV
+\frac1{Re}\int_V\left[\frac{\partial N}{\partial X}\right]^T\frac{\partial V_x}{\partial X_i}dV
-\int_V\left[\frac{\partial N}{\partial X}\right]^T\delta_{xi}P\,dV\\[6pt]
&+\frac1{Re}\int_V\left[\frac{\partial N}{\partial Y}\right]^T\frac{\partial V_i}{\partial Y}dV
+\frac1{Re}\int_V\left[\frac{\partial N}{\partial Y}\right]^T\frac{\partial V_y}{\partial X_i}dV
-\int_V\left[\frac{\partial N}{\partial Y}\right]^T\delta_{yi}P\,dV\\[6pt]
&+\frac1{Re}\int_V\left[\frac{\partial N}{\partial Z}\right]^T\frac{\partial V_i}{\partial Z}dV
+\frac1{Re}\int_V\left[\frac{\partial N}{\partial Z}\right]^T\frac{\partial V_z}{\partial X_i}dV
-\int_V\left[\frac{\partial N}{\partial Z}\right]^T\delta_{zi}P\,dV\\[6pt]
&+\frac{2K^*}{We}n_i\int_S[N]^T dS\\[6pt]
&-g_i^*\int_V[N]^T dV
\end{aligned}
\]
速度、圧力を内挿関数で表示して
\[
\begin{aligned}
&={}\int_V[N]^T[N]dV\,
\frac{\{V_i\}^{\tau+\Delta\tau}-\{V_i\}^{\tau}}{\Delta\tau}\\[6pt]
&+V_x\int_V[N]^T\left[\frac{\partial N}{\partial X}\right]dV\{V_i\}
+V_y\int_V[N]^T\left[\frac{\partial N}{\partial Y}\right]dV\{V_i\}
+V_z\int_V[N]^T\left[\frac{\partial N}{\partial Z}\right]dV\{V_i\}\\[6pt]
&+\frac1{Re}\int_V\left[\frac{\partial N}{\partial X}\right]^T
\frac{\partial[N]\{V_i\}}{\partial X}dV
+\frac1{Re}\int_V\left[\frac{\partial N}{\partial X}\right]^T
\frac{\partial[N]\{V_x\}}{\partial X_i}dV
-\delta_{xi}\int_V\left[\frac{\partial N}{\partial X}\right]^T[N]\{P\}dV\\[6pt]
&+\frac1{Re}\int_V\left[\frac{\partial N}{\partial Y}\right]^T
\frac{\partial[N]\{V_i\}}{\partial Y}dV
+\frac1{Re}\int_V\left[\frac{\partial N}{\partial Y}\right]^T
\frac{\partial[N]\{V_y\}}{\partial X_i}dV
-\delta_{yi}\int_V\left[\frac{\partial N}{\partial Y}\right]^T[N]\{P\}dV\\[6pt]
&+\frac1{Re}\int_V\left[\frac{\partial N}{\partial Z}\right]^T
\frac{\partial[N]\{V_i\}}{\partial Z}dV
+\frac1{Re}\int_V\left[\frac{\partial N}{\partial Z}\right]^T
\frac{\partial[N]\{V_z\}}{\partial X_i}dV
-\delta_{zi}\int_V\left[\frac{\partial N}{\partial Z}\right]^T[N]\{P\}dV\\[6pt]
&+\frac{2K^*}{We}n_i\int_S[N]^T dS\\[6pt]
&-g_i^*\int_V[N]^T dV
\end{aligned}
\]
形状関数内挿後の節点自由度は積分変数に依存しないため、積分の外に出します。
\[
\begin{aligned}
&={}\int_V[N]^T[N]dV\,
\frac{\{V_i\}^{\tau+\Delta\tau}-\{V_i\}^{\tau}}{\Delta\tau}\\[6pt]
&+V_x\int_V[N]^T\left[\frac{\partial N}{\partial X}\right]dV\{V_i\}
+V_y\int_V[N]^T\left[\frac{\partial N}{\partial Y}\right]dV\{V_i\}
+V_z\int_V[N]^T\left[\frac{\partial N}{\partial Z}\right]dV\{V_i\}\\[6pt]
&+\frac1{Re}\int_V\left[\frac{\partial N}{\partial X}\right]^T\left[\frac{\partial N}{\partial X}\right]dV\{V_i\}
+\frac1{Re}\int_V\left[\frac{\partial N}{\partial X}\right]^T\left[\frac{\partial N}{\partial X_i}\right]dV\{V_x\}
-\delta_{xi}\int_V\left[\frac{\partial N}{\partial X}\right]^T[N]dV\{P\}\\[6pt]
&+\frac1{Re}\int_V\left[\frac{\partial N}{\partial Y}\right]^T\left[\frac{\partial N}{\partial Y}\right]dV\{V_i\}
+\frac1{Re}\int_V\left[\frac{\partial N}{\partial Y}\right]^T\left[\frac{\partial N}{\partial X_i}\right]dV\{V_y\}
-\delta_{yi}\int_V\left[\frac{\partial N}{\partial Y}\right]^T[N]dV\{P\}\\[6pt]
&+\frac1{Re}\int_V\left[\frac{\partial N}{\partial Z}\right]^T\left[\frac{\partial N}{\partial Z}\right]dV\{V_i\}
+\frac1{Re}\int_V\left[\frac{\partial N}{\partial Z}\right]^T\left[\frac{\partial N}{\partial X_i}\right]dV\{V_z\}
-\delta_{zi}\int_V\left[\frac{\partial N}{\partial Z}\right]^T[N]dV\{P\}\\[6pt]
&+\frac{2K^*}{We}n_i\int_S[N]^T dS\\[6pt]
&-g_i^*\int_V[N]^T dV
\qquad (i=1,2,3)
\end{aligned}
\]
行列式で表す
蓄積量
\[
=\int_V
\begin{bmatrix}
N_1N_1&N_1N_2&N_1N_3&N_1N_4\\
N_2N_1&N_2N_2&N_2N_3&N_2N_4\\
N_3N_1&N_3N_2&N_3N_3&N_3N_4\\
N_4N_1&N_4N_2&N_4N_3&N_4N_4
\end{bmatrix}
dV\,
\frac{\{V_i\}^{\tau+\Delta\tau}-\{V_i\}^{\tau}}{\Delta\tau}
\]
対流項
\[
\begin{aligned}
&+V_x\int_V
\begin{bmatrix}
N_1\frac{\partial N_1}{\partial X}&N_1\frac{\partial N_2}{\partial X}&N_1\frac{\partial N_3}{\partial X}&N_1\frac{\partial N_4}{\partial X}\\
N_2\frac{\partial N_1}{\partial X}&N_2\frac{\partial N_2}{\partial X}&N_2\frac{\partial N_3}{\partial X}&N_2\frac{\partial N_4}{\partial X}\\
N_3\frac{\partial N_1}{\partial X}&N_3\frac{\partial N_2}{\partial X}&N_3\frac{\partial N_3}{\partial X}&N_3\frac{\partial N_4}{\partial X}\\
N_4\frac{\partial N_1}{\partial X}&N_4\frac{\partial N_2}{\partial X}&N_4\frac{\partial N_3}{\partial X}&N_4\frac{\partial N_4}{\partial X}
\end{bmatrix}dV\{V_i\}\\[6pt]
&+V_y\int_V
\begin{bmatrix}
N_1\frac{\partial N_1}{\partial Y}&N_1\frac{\partial N_2}{\partial Y}&N_1\frac{\partial N_3}{\partial Y}&N_1\frac{\partial N_4}{\partial Y}\\
N_2\frac{\partial N_1}{\partial Y}&N_2\frac{\partial N_2}{\partial Y}&N_2\frac{\partial N_3}{\partial Y}&N_2\frac{\partial N_4}{\partial Y}\\
N_3\frac{\partial N_1}{\partial Y}&N_3\frac{\partial N_2}{\partial Y}&N_3\frac{\partial N_3}{\partial Y}&N_3\frac{\partial N_4}{\partial Y}\\
N_4\frac{\partial N_1}{\partial Y}&N_4\frac{\partial N_2}{\partial Y}&N_4\frac{\partial N_3}{\partial Y}&N_4\frac{\partial N_4}{\partial Y}
\end{bmatrix}dV\{V_i\}\\[6pt]
&+V_z\int_V
\begin{bmatrix}
N_1\frac{\partial N_1}{\partial Z}&N_1\frac{\partial N_2}{\partial Z}&N_1\frac{\partial N_3}{\partial Z}&N_1\frac{\partial N_4}{\partial Z}\\
N_2\frac{\partial N_1}{\partial Z}&N_2\frac{\partial N_2}{\partial Z}&N_2\frac{\partial N_3}{\partial Z}&N_2\frac{\partial N_4}{\partial Z}\\
N_3\frac{\partial N_1}{\partial Z}&N_3\frac{\partial N_2}{\partial Z}&N_3\frac{\partial N_3}{\partial Z}&N_3\frac{\partial N_4}{\partial Z}\\
N_4\frac{\partial N_1}{\partial Z}&N_4\frac{\partial N_2}{\partial Z}&N_4\frac{\partial N_3}{\partial Z}&N_4\frac{\partial N_4}{\partial Z}
\end{bmatrix}dV\{V_i\}
\end{aligned}
\]
x軸方向の粘性項と圧力項
\[
\begin{aligned}
&+\frac1{Re}\int_V
\begin{bmatrix}
\frac{\partial N_1}{\partial X}\frac{\partial N_1}{\partial X}&\frac{\partial N_1}{\partial X}\frac{\partial N_2}{\partial X}&\frac{\partial N_1}{\partial X}\frac{\partial N_3}{\partial X}&\frac{\partial N_1}{\partial X}\frac{\partial N_4}{\partial X}\\
\frac{\partial N_2}{\partial X}\frac{\partial N_1}{\partial X}&\frac{\partial N_2}{\partial X}\frac{\partial N_2}{\partial X}&\frac{\partial N_2}{\partial X}\frac{\partial N_3}{\partial X}&\frac{\partial N_2}{\partial X}\frac{\partial N_4}{\partial X}\\
\frac{\partial N_3}{\partial X}\frac{\partial N_1}{\partial X}&\frac{\partial N_3}{\partial X}\frac{\partial N_2}{\partial X}&\frac{\partial N_3}{\partial X}\frac{\partial N_3}{\partial X}&\frac{\partial N_3}{\partial X}\frac{\partial N_4}{\partial X}\\
\frac{\partial N_4}{\partial X}\frac{\partial N_1}{\partial X}&\frac{\partial N_4}{\partial X}\frac{\partial N_2}{\partial X}&\frac{\partial N_4}{\partial X}\frac{\partial N_3}{\partial X}&\frac{\partial N_4}{\partial X}\frac{\partial N_4}{\partial X}
\end{bmatrix}dV\{V_i\}\\[6pt]
&+\frac1{Re}\int_V
\begin{bmatrix}
\frac{\partial N_1}{\partial X}\frac{\partial N_1}{\partial X_i}&\frac{\partial N_1}{\partial X}\frac{\partial N_2}{\partial X_i}&\frac{\partial N_1}{\partial X}\frac{\partial N_3}{\partial X_i}&\frac{\partial N_1}{\partial X}\frac{\partial N_4}{\partial X_i}\\
\frac{\partial N_2}{\partial X}\frac{\partial N_1}{\partial X_i}&\frac{\partial N_2}{\partial X}\frac{\partial N_2}{\partial X_i}&\frac{\partial N_2}{\partial X}\frac{\partial N_3}{\partial X_i}&\frac{\partial N_2}{\partial X}\frac{\partial N_4}{\partial X_i}\\
\frac{\partial N_3}{\partial X}\frac{\partial N_1}{\partial X_i}&\frac{\partial N_3}{\partial X}\frac{\partial N_2}{\partial X_i}&\frac{\partial N_3}{\partial X}\frac{\partial N_3}{\partial X_i}&\frac{\partial N_3}{\partial X}\frac{\partial N_4}{\partial X_i}\\
\frac{\partial N_4}{\partial X}\frac{\partial N_1}{\partial X_i}&\frac{\partial N_4}{\partial X}\frac{\partial N_2}{\partial X_i}&\frac{\partial N_4}{\partial X}\frac{\partial N_3}{\partial X_i}&\frac{\partial N_4}{\partial X}\frac{\partial N_4}{\partial X_i}
\end{bmatrix}dV\{V_x\}\\[6pt]
&-\delta_{xi}\int_V
\begin{bmatrix}
\frac{\partial N_1}{\partial X}N_1&\frac{\partial N_1}{\partial X}N_2&\frac{\partial N_1}{\partial X}N_3&\frac{\partial N_1}{\partial X}N_4\\
\frac{\partial N_2}{\partial X}N_1&\frac{\partial N_2}{\partial X}N_2&\frac{\partial N_2}{\partial X}N_3&\frac{\partial N_2}{\partial X}N_4\\
\frac{\partial N_3}{\partial X}N_1&\frac{\partial N_3}{\partial X}N_2&\frac{\partial N_3}{\partial X}N_3&\frac{\partial N_3}{\partial X}N_4\\
\frac{\partial N_4}{\partial X}N_1&\frac{\partial N_4}{\partial X}N_2&\frac{\partial N_4}{\partial X}N_3&\frac{\partial N_4}{\partial X}N_4
\end{bmatrix}dV\{P\}
\end{aligned}
\]
y軸方向の粘性項と圧力項
\[
\begin{aligned}
&+\frac1{Re}\int_V
\begin{bmatrix}
\frac{\partial N_1}{\partial Y}\frac{\partial N_1}{\partial Y}&\frac{\partial N_1}{\partial Y}\frac{\partial N_2}{\partial Y}&\frac{\partial N_1}{\partial Y}\frac{\partial N_3}{\partial Y}&\frac{\partial N_1}{\partial Y}\frac{\partial N_4}{\partial Y}\\
\frac{\partial N_2}{\partial Y}\frac{\partial N_1}{\partial Y}&\frac{\partial N_2}{\partial Y}\frac{\partial N_2}{\partial Y}&\frac{\partial N_2}{\partial Y}\frac{\partial N_3}{\partial Y}&\frac{\partial N_2}{\partial Y}\frac{\partial N_4}{\partial Y}\\
\frac{\partial N_3}{\partial Y}\frac{\partial N_1}{\partial Y}&\frac{\partial N_3}{\partial Y}\frac{\partial N_2}{\partial Y}&\frac{\partial N_3}{\partial Y}\frac{\partial N_3}{\partial Y}&\frac{\partial N_3}{\partial Y}\frac{\partial N_4}{\partial Y}\\
\frac{\partial N_4}{\partial Y}\frac{\partial N_1}{\partial Y}&\frac{\partial N_4}{\partial Y}\frac{\partial N_2}{\partial Y}&\frac{\partial N_4}{\partial Y}\frac{\partial N_3}{\partial Y}&\frac{\partial N_4}{\partial Y}\frac{\partial N_4}{\partial Y}
\end{bmatrix}dV\{V_i\}\\[6pt]
&+\frac1{Re}\int_V
\begin{bmatrix}
\frac{\partial N_1}{\partial Y}\frac{\partial N_1}{\partial X_i}&\frac{\partial N_1}{\partial Y}\frac{\partial N_2}{\partial X_i}&\frac{\partial N_1}{\partial Y}\frac{\partial N_3}{\partial X_i}&\frac{\partial N_1}{\partial Y}\frac{\partial N_4}{\partial X_i}\\
\frac{\partial N_2}{\partial Y}\frac{\partial N_1}{\partial X_i}&\frac{\partial N_2}{\partial Y}\frac{\partial N_2}{\partial X_i}&\frac{\partial N_2}{\partial Y}\frac{\partial N_3}{\partial X_i}&\frac{\partial N_2}{\partial Y}\frac{\partial N_4}{\partial X_i}\\
\frac{\partial N_3}{\partial Y}\frac{\partial N_1}{\partial X_i}&\frac{\partial N_3}{\partial Y}\frac{\partial N_2}{\partial X_i}&\frac{\partial N_3}{\partial Y}\frac{\partial N_3}{\partial X_i}&\frac{\partial N_3}{\partial Y}\frac{\partial N_4}{\partial X_i}\\
\frac{\partial N_4}{\partial Y}\frac{\partial N_1}{\partial X_i}&\frac{\partial N_4}{\partial Y}\frac{\partial N_2}{\partial X_i}&\frac{\partial N_4}{\partial Y}\frac{\partial N_3}{\partial X_i}&\frac{\partial N_4}{\partial Y}\frac{\partial N_4}{\partial X_i}
\end{bmatrix}dV\{V_y\}\\[6pt]
&-\delta_{yi}\int_V
\begin{bmatrix}
\frac{\partial N_1}{\partial Y}N_1&\frac{\partial N_1}{\partial Y}N_2&\frac{\partial N_1}{\partial Y}N_3&\frac{\partial N_1}{\partial Y}N_4\\
\frac{\partial N_2}{\partial Y}N_1&\frac{\partial N_2}{\partial Y}N_2&\frac{\partial N_2}{\partial Y}N_3&\frac{\partial N_2}{\partial Y}N_4\\
\frac{\partial N_3}{\partial Y}N_1&\frac{\partial N_3}{\partial Y}N_2&\frac{\partial N_3}{\partial Y}N_3&\frac{\partial N_3}{\partial Y}N_4\\
\frac{\partial N_4}{\partial Y}N_1&\frac{\partial N_4}{\partial Y}N_2&\frac{\partial N_4}{\partial Y}N_3&\frac{\partial N_4}{\partial Y}N_4
\end{bmatrix}dV\{P\}
\end{aligned}
\]
z軸方向の粘性項と圧力項
\[
\begin{aligned}
&+\frac1{Re}\int_V
\begin{bmatrix}
\dfrac{\partial N_1}{\partial Z}\dfrac{\partial N_1}{\partial Z}&\dfrac{\partial N_1}{\partial Z}\dfrac{\partial N_2}{\partial Z}&\dfrac{\partial N_1}{\partial Z}\dfrac{\partial N_3}{\partial Z}&\dfrac{\partial N_1}{\partial Z}\dfrac{\partial N_4}{\partial Z}\\
\dfrac{\partial N_2}{\partial Z}\dfrac{\partial N_1}{\partial Z}&\dfrac{\partial N_2}{\partial Z}\dfrac{\partial N_2}{\partial Z}&\dfrac{\partial N_2}{\partial Z}\dfrac{\partial N_3}{\partial Z}&\dfrac{\partial N_2}{\partial Z}\dfrac{\partial N_4}{\partial Z}\\
\dfrac{\partial N_3}{\partial Z}\dfrac{\partial N_1}{\partial Z}&\dfrac{\partial N_3}{\partial Z}\dfrac{\partial N_2}{\partial Z}&\dfrac{\partial N_3}{\partial Z}\dfrac{\partial N_3}{\partial Z}&\dfrac{\partial N_3}{\partial Z}\dfrac{\partial N_4}{\partial Z}\\
\dfrac{\partial N_4}{\partial Z}\dfrac{\partial N_1}{\partial Z}&\dfrac{\partial N_4}{\partial Z}\dfrac{\partial N_2}{\partial Z}&\dfrac{\partial N_4}{\partial Z}\dfrac{\partial N_3}{\partial Z}&\dfrac{\partial N_4}{\partial Z}\dfrac{\partial N_4}{\partial Z}
\end{bmatrix}dV\{V_i\}\\[6pt]
&+\frac1{Re}\int_V
\begin{bmatrix}
\dfrac{\partial N_1}{\partial Z}\dfrac{\partial N_1}{\partial X_i}&\dfrac{\partial N_1}{\partial Z}\dfrac{\partial N_2}{\partial X_i}&\dfrac{\partial N_1}{\partial Z}\dfrac{\partial N_3}{\partial X_i}&\dfrac{\partial N_1}{\partial Z}\dfrac{\partial N_4}{\partial X_i}\\
\dfrac{\partial N_2}{\partial Z}\dfrac{\partial N_1}{\partial X_i}&\dfrac{\partial N_2}{\partial Z}\dfrac{\partial N_2}{\partial X_i}&\dfrac{\partial N_2}{\partial Z}\dfrac{\partial N_3}{\partial X_i}&\dfrac{\partial N_2}{\partial Z}\dfrac{\partial N_4}{\partial X_i}\\
\dfrac{\partial N_3}{\partial Z}\dfrac{\partial N_1}{\partial X_i}&\dfrac{\partial N_3}{\partial Z}\dfrac{\partial N_2}{\partial X_i}&\dfrac{\partial N_3}{\partial Z}\dfrac{\partial N_3}{\partial X_i}&\dfrac{\partial N_3}{\partial Z}\dfrac{\partial N_4}{\partial X_i}\\
\dfrac{\partial N_4}{\partial Z}\dfrac{\partial N_1}{\partial X_i}&\dfrac{\partial N_4}{\partial Z}\dfrac{\partial N_2}{\partial X_i}&\dfrac{\partial N_4}{\partial Z}\dfrac{\partial N_3}{\partial X_i}&\dfrac{\partial N_4}{\partial Z}\dfrac{\partial N_4}{\partial X_i}
\end{bmatrix}dV\{V_z\}\\[6pt]
&-\delta_{zi}\int_V
\begin{bmatrix}
\dfrac{\partial N_1}{\partial Z}N_1&\dfrac{\partial N_1}{\partial Z}N_2&\dfrac{\partial N_1}{\partial Z}N_3&\dfrac{\partial N_1}{\partial Z}N_4\\
\dfrac{\partial N_2}{\partial Z}N_1&\dfrac{\partial N_2}{\partial Z}N_2&\dfrac{\partial N_2}{\partial Z}N_3&\dfrac{\partial N_2}{\partial Z}N_4\\
\dfrac{\partial N_3}{\partial Z}N_1&\dfrac{\partial N_3}{\partial Z}N_2&\dfrac{\partial N_3}{\partial Z}N_3&\dfrac{\partial N_3}{\partial Z}N_4\\
\dfrac{\partial N_4}{\partial Z}N_1&\dfrac{\partial N_4}{\partial Z}N_2&\dfrac{\partial N_4}{\partial Z}N_3&\dfrac{\partial N_4}{\partial Z}N_4
\end{bmatrix}dV\{P\}
\end{aligned}
\]
表面張力項
\[
+\frac{2K^*}{We}n_i\int_S
\begin{bmatrix}N_1\\N_2\\N_3\end{bmatrix}dS
\]
重力項
\[
-g_i^*\int_V
\begin{bmatrix}N_1\\N_2\\N_3\\N_4\end{bmatrix}dV
\qquad (i=1,2,3)
\]
内挿関数を形状関数に直す
\[
=\int_V
\begin{bmatrix}
L_1L_1&L_1L_2&L_1L_3&L_1L_4\\
L_2L_1&L_2L_2&L_2L_3&L_2L_4\\
L_3L_1&L_3L_2&L_3L_3&L_3L_4\\
L_4L_1&L_4L_2&L_4L_3&L_4L_4
\end{bmatrix}dV\,
\frac{\{V_i\}^{\tau+\Delta\tau}-\{V_i\}^{\tau}}{\Delta\tau}
\]
対流項
\[
\begin{aligned}
&+V_x\int_V\frac1{6V}
\begin{bmatrix}
L_1c_{1x}&L_1c_{2x}&L_1c_{3x}&L_1c_{4x}\\
L_2c_{1x}&L_2c_{2x}&L_2c_{3x}&L_2c_{4x}\\
L_3c_{1x}&L_3c_{2x}&L_3c_{3x}&L_3c_{4x}\\
L_4c_{1x}&L_4c_{2x}&L_4c_{3x}&L_4c_{4x}
\end{bmatrix}dV\{V_i\}\\[6pt]
&+V_y\int_V\frac1{6V}
\begin{bmatrix}
L_1c_{1y}&L_1c_{2y}&L_1c_{3y}&L_1c_{4y}\\
L_2c_{1y}&L_2c_{2y}&L_2c_{3y}&L_2c_{4y}\\
L_3c_{1y}&L_3c_{2y}&L_3c_{3y}&L_3c_{4y}\\
L_4c_{1y}&L_4c_{2y}&L_4c_{3y}&L_4c_{4y}
\end{bmatrix}dV\{V_i\}\\[6pt]
&+V_z\int_V\frac1{6V}
\begin{bmatrix}
L_1c_{1z}&L_1c_{2z}&L_1c_{3z}&L_1c_{4z}\\
L_2c_{1z}&L_2c_{2z}&L_2c_{3z}&L_2c_{4z}\\
L_3c_{1z}&L_3c_{2z}&L_3c_{3z}&L_3c_{4z}\\
L_4c_{1z}&L_4c_{2z}&L_4c_{3z}&L_4c_{4z}
\end{bmatrix}dV\{V_i\}
\end{aligned}
\]
x軸方向の粘性項と圧力項
\[
\begin{aligned}
&+\frac1{Re}\int_V\frac1{36V^2}
\begin{bmatrix}
c_{1x}c_{1x}&c_{1x}c_{2x}&c_{1x}c_{3x}&c_{1x}c_{4x}\\
c_{2x}c_{1x}&c_{2x}c_{2x}&c_{2x}c_{3x}&c_{2x}c_{4x}\\
c_{3x}c_{1x}&c_{3x}c_{2x}&c_{3x}c_{3x}&c_{3x}c_{4x}\\
c_{4x}c_{1x}&c_{4x}c_{2x}&c_{4x}c_{3x}&c_{4x}c_{4x}
\end{bmatrix}dV\{V_i\}\\[6pt]
&+\frac1{Re}\int_V\frac1{36V^2}
\begin{bmatrix}
c_{1x}c_{1i}&c_{1x}c_{2i}&c_{1x}c_{3i}&c_{1x}c_{4i}\\
c_{2x}c_{1i}&c_{2x}c_{2i}&c_{2x}c_{3i}&c_{2x}c_{4i}\\
c_{3x}c_{1i}&c_{3x}c_{2i}&c_{3x}c_{3i}&c_{3x}c_{4i}\\
c_{4x}c_{1i}&c_{4x}c_{2i}&c_{4x}c_{3i}&c_{4x}c_{4i}
\end{bmatrix}dV\{V_x\}\\[6pt]
&-\delta_{xi}\int_V\frac1{6V}
\begin{bmatrix}
c_{1x}L_1&c_{1x}L_2&c_{1x}L_3&c_{1x}L_4\\
c_{2x}L_1&c_{2x}L_2&c_{2x}L_3&c_{2x}L_4\\
c_{3x}L_1&c_{3x}L_2&c_{3x}L_3&c_{3x}L_4\\
c_{4x}L_1&c_{4x}L_2&c_{4x}L_3&c_{4x}L_4
\end{bmatrix}dV\{P\}
\end{aligned}
\]
y軸方向の粘性項と圧力項
\[
\begin{aligned}
&+\frac1{Re}\int_V\frac1{36V^2}
\begin{bmatrix}
c_{1y}c_{1y}&c_{1y}c_{2y}&c_{1y}c_{3y}&c_{1y}c_{4y}\\
c_{2y}c_{1y}&c_{2y}c_{2y}&c_{2y}c_{3y}&c_{2y}c_{4y}\\
c_{3y}c_{1y}&c_{3y}c_{2y}&c_{3y}c_{3y}&c_{3y}c_{4y}\\
c_{4y}c_{1y}&c_{4y}c_{2y}&c_{4y}c_{3y}&c_{4y}c_{4y}
\end{bmatrix}dV\{V_i\}\\[6pt]
&+\frac1{Re}\int_V\frac1{36V^2}
\begin{bmatrix}
c_{1y}c_{1i}&c_{1y}c_{2i}&c_{1y}c_{3i}&c_{1y}c_{4i}\\
c_{2y}c_{1i}&c_{2y}c_{2i}&c_{2y}c_{3i}&c_{2y}c_{4i}\\
c_{3y}c_{1i}&c_{3y}c_{2i}&c_{3y}c_{3i}&c_{3y}c_{4i}\\
c_{4y}c_{1i}&c_{4y}c_{2i}&c_{4y}c_{3i}&c_{4y}c_{4i}
\end{bmatrix}dV\{V_y\}\\[6pt]
&-\delta_{yi}\int_V\frac1{6V}
\begin{bmatrix}
c_{1y}L_1&c_{1y}L_2&c_{1y}L_3&c_{1y}L_4\\
c_{2y}L_1&c_{2y}L_2&c_{2y}L_3&c_{2y}L_4\\
c_{3y}L_1&c_{3y}L_2&c_{3y}L_3&c_{3y}L_4\\
c_{4y}L_1&c_{4y}L_2&c_{4y}L_3&c_{4y}L_4
\end{bmatrix}dV\{P\}
\end{aligned}
\]
z軸方向の粘性項と圧力項
\[
\begin{aligned}
&+\frac1{Re}\int_V\frac1{36V^2}
\begin{bmatrix}
c_{1z}c_{1z}&c_{1z}c_{2z}&c_{1z}c_{3z}&c_{1z}c_{4z}\\
c_{2z}c_{1z}&c_{2z}c_{2z}&c_{2z}c_{3z}&c_{2z}c_{4z}\\
c_{3z}c_{1z}&c_{3z}c_{2z}&c_{3z}c_{3z}&c_{3z}c_{4z}\\
c_{4z}c_{1z}&c_{4z}c_{2z}&c_{4z}c_{3z}&c_{4z}c_{4z}
\end{bmatrix}dV\{V_i\}\\[6pt]
&+\frac1{Re}\int_V\frac1{36V^2}
\begin{bmatrix}
c_{1z}c_{1i}&c_{1z}c_{2i}&c_{1z}c_{3i}&c_{1z}c_{4i}\\
c_{2z}c_{1i}&c_{2z}c_{2i}&c_{2z}c_{3i}&c_{2z}c_{4i}\\
c_{3z}c_{1i}&c_{3z}c_{2i}&c_{3z}c_{3i}&c_{3z}c_{4i}\\
c_{4z}c_{1i}&c_{4z}c_{2i}&c_{4z}c_{3i}&c_{4z}c_{4i}
\end{bmatrix}dV\{V_z\}\\[6pt]
&-\delta_{zi}\int_V\frac1{6V}
\begin{bmatrix}
c_{1z}L_1&c_{1z}L_2&c_{1z}L_3&c_{1z}L_4\\
c_{2z}L_1&c_{2z}L_2&c_{2z}L_3&c_{2z}L_4\\
c_{3z}L_1&c_{3z}L_2&c_{3z}L_3&c_{3z}L_4\\
c_{4z}L_1&c_{4z}L_2&c_{4z}L_3&c_{4z}L_4
\end{bmatrix}dV\{P\}
\end{aligned}
\]
表面張力項
\[
+\frac{2K^*}{We}n_i\int_S
\begin{bmatrix}L_1\\L_2\\L_3\end{bmatrix}dS
\]
重力項
\[
-g_i^*\int_V
\begin{bmatrix}L_1\\L_2\\L_3\\L_4\end{bmatrix}^{T}dV
\qquad (i=1,2,3)
\]
ここで、面積積分、体積積分の公式より
\[
\int_V L_1^pL_2^qL_3^rL_4^s\,dV
=\frac{p!q!r!s!}{(p+q+r+s+3)!}\,6V
\]
\[
\int_VL_iL_j\,dV
=\begin{cases}
\displaystyle
\frac{1!1!}{(1+1+3)!}\,6V
=\frac{6}{5!}V
=\frac{1}{20}V & (i\ne j)\\[6pt]
\displaystyle
\frac{2!}{(1+1+3)!}\,6V
=\frac{12}{5!}V
=\frac{1}{10}V & (i=j)
\end{cases}
\]
\[
\int_VL_i\,dV
=\frac{1!}{(1+3)!}\,6V
=\frac{6}{4!}V
=\frac14V
\]
\[
\int_SL_1^pL_2^qL_3^r\,dS
=\frac{p!q!r!}{(p+q+r+2)!}\,2S
\]
\[
\int_SL_i\,dS
=\frac{1!}{(1+2)!}\,2S
=\frac13S
\]
形状関数を積分すると
\[
=\frac1{20}V
\begin{bmatrix}
2&1&1&1\\
1&2&1&1\\
1&1&2&1\\
1&1&1&2
\end{bmatrix}
\frac{\{V_i\}^{\tau+\Delta\tau}-\{V_i\}^{\tau}}{\Delta\tau}
\]
対流項
\[
\begin{aligned}
&+V_x\frac1{6V}\frac{V}{4}
\begin{bmatrix}
c_{1x}&c_{2x}&c_{3x}&c_{4x}\\
c_{1x}&c_{2x}&c_{3x}&c_{4x}\\
c_{1x}&c_{2x}&c_{3x}&c_{4x}\\
c_{1x}&c_{2x}&c_{3x}&c_{4x}
\end{bmatrix}\{V_i\}\\[6pt]
&+V_y\frac1{6V}\frac{V}{4}
\begin{bmatrix}
c_{1y}&c_{2y}&c_{3y}&c_{4y}\\
c_{1y}&c_{2y}&c_{3y}&c_{4y}\\
c_{1y}&c_{2y}&c_{3y}&c_{4y}\\
c_{1y}&c_{2y}&c_{3y}&c_{4y}
\end{bmatrix}\{V_i\}\\[6pt]
&+V_z\frac1{6V}\frac{V}{4}
\begin{bmatrix}
c_{1z}&c_{2z}&c_{3z}&c_{4z}\\
c_{1z}&c_{2z}&c_{3z}&c_{4z}\\
c_{1z}&c_{2z}&c_{3z}&c_{4z}\\
c_{1z}&c_{2z}&c_{3z}&c_{4z}
\end{bmatrix}\{V_i\}
\end{aligned}
\]
x軸方向の粘性項と圧力項
\[
\begin{aligned}
&+\frac1{Re}\frac1{36V^2}V
\begin{bmatrix}
c_{1x}c_{1x}&c_{1x}c_{2x}&c_{1x}c_{3x}&c_{1x}c_{4x}\\
c_{2x}c_{1x}&c_{2x}c_{2x}&c_{2x}c_{3x}&c_{2x}c_{4x}\\
c_{3x}c_{1x}&c_{3x}c_{2x}&c_{3x}c_{3x}&c_{3x}c_{4x}\\
c_{4x}c_{1x}&c_{4x}c_{2x}&c_{4x}c_{3x}&c_{4x}c_{4x}
\end{bmatrix}\{V_i\}\\[6pt]
&+\frac1{Re}\frac1{36V^2}V
\begin{bmatrix}
c_{1x}c_{1i}&c_{1x}c_{2i}&c_{1x}c_{3i}&c_{1x}c_{4i}\\
c_{2x}c_{1i}&c_{2x}c_{2i}&c_{2x}c_{3i}&c_{2x}c_{4i}\\
c_{3x}c_{1i}&c_{3x}c_{2i}&c_{3x}c_{3i}&c_{3x}c_{4i}\\
c_{4x}c_{1i}&c_{4x}c_{2i}&c_{4x}c_{3i}&c_{4x}c_{4i}
\end{bmatrix}\{V_x\}\\[6pt]
&-\delta_{xi}\frac1{6V}\frac{V}{4}
\begin{bmatrix}
c_{1x}&c_{1x}&c_{1x}&c_{1x}\\
c_{2x}&c_{2x}&c_{2x}&c_{2x}\\
c_{3x}&c_{3x}&c_{3x}&c_{3x}\\
c_{4x}&c_{4x}&c_{4x}&c_{4x}
\end{bmatrix}\{P\}
\end{aligned}
\]
y軸方向の粘性項と圧力項
\[
\begin{aligned}
&+\frac1{Re}\frac1{36V^2}V
\begin{bmatrix}
c_{1y}c_{1y}&c_{1y}c_{2y}&c_{1y}c_{3y}&c_{1y}c_{4y}\\
c_{2y}c_{1y}&c_{2y}c_{2y}&c_{2y}c_{3y}&c_{2y}c_{4y}\\
c_{3y}c_{1y}&c_{3y}c_{2y}&c_{3y}c_{3y}&c_{3y}c_{4y}\\
c_{4y}c_{1y}&c_{4y}c_{2y}&c_{4y}c_{3y}&c_{4y}c_{4y}
\end{bmatrix}\{V_i\}\\[6pt]
&+\frac1{Re}\frac1{36V^2}V
\begin{bmatrix}
c_{1y}c_{1i}&c_{1y}c_{2i}&c_{1y}c_{3i}&c_{1y}c_{4i}\\
c_{2y}c_{1i}&c_{2y}c_{2i}&c_{2y}c_{3i}&c_{2y}c_{4i}\\
c_{3y}c_{1i}&c_{3y}c_{2i}&c_{3y}c_{3i}&c_{3y}c_{4i}\\
c_{4y}c_{1i}&c_{4y}c_{2i}&c_{4y}c_{3i}&c_{4y}c_{4i}
\end{bmatrix}\{V_y\}\\[6pt]
&-\delta_{yi}\frac1{6V}\frac{V}{4}
\begin{bmatrix}
c_{1y}&c_{1y}&c_{1y}&c_{1y}\\
c_{2y}&c_{2y}&c_{2y}&c_{2y}\\
c_{3y}&c_{3y}&c_{3y}&c_{3y}\\
c_{4y}&c_{4y}&c_{4y}&c_{4y}
\end{bmatrix}\{P\}
\end{aligned}
\]
z軸方向の粘性項と圧力項
\[
\begin{aligned}
&+\frac1{Re}\frac1{36V^2}V
\begin{bmatrix}
c_{1z}c_{1z}&c_{1z}c_{2z}&c_{1z}c_{3z}&c_{1z}c_{4z}\\
c_{2z}c_{1z}&c_{2z}c_{2z}&c_{2z}c_{3z}&c_{2z}c_{4z}\\
c_{3z}c_{1z}&c_{3z}c_{2z}&c_{3z}c_{3z}&c_{3z}c_{4z}\\
c_{4z}c_{1z}&c_{4z}c_{2z}&c_{4z}c_{3z}&c_{4z}c_{4z}
\end{bmatrix}\{V_i\}\\[6pt]
&+\frac1{Re}\frac1{36V^2}V
\begin{bmatrix}
c_{1z}c_{1i}&c_{1z}c_{2i}&c_{1z}c_{3i}&c_{1z}c_{4i}\\
c_{2z}c_{1i}&c_{2z}c_{2i}&c_{2z}c_{3i}&c_{2z}c_{4i}\\
c_{3z}c_{1i}&c_{3z}c_{2i}&c_{3z}c_{3i}&c_{3z}c_{4i}\\
c_{4z}c_{1i}&c_{4z}c_{2i}&c_{4z}c_{3i}&c_{4z}c_{4i}
\end{bmatrix}\{V_z\}\\[6pt]
&-\delta_{zi}\frac1{6V}\frac{V}{4}
\begin{bmatrix}
c_{1z}&c_{1z}&c_{1z}&c_{1z}\\
c_{2z}&c_{2z}&c_{2z}&c_{2z}\\
c_{3z}&c_{3z}&c_{3z}&c_{3z}\\
c_{4z}&c_{4z}&c_{4z}&c_{4z}
\end{bmatrix}\{P\}
\end{aligned}
\]
表面張力項
\[
+\frac{2K^*}{We}n_i\frac{S}{3}
\begin{bmatrix}1\\1\\1\end{bmatrix}
\]
重力項
\[
-g_i^*\frac{V}{4}
\begin{bmatrix}1\\1\\1\\1\end{bmatrix}
\qquad(i=1,2,3)
\]
境界三角形で得られる3節点の表面力ベクトルは、要素方程式へ加算するときに境界面の節点番号から四面体4節点へ写像します。以下の式ではこのアセンブリ写像を省略しています。面局所ベクトルを \(\mathbf f_S\) とすると、要素ベクトルは \(\mathbf f_e=A_S^T\mathbf f_S\) です。例えば境界面が要素節点1-2-3なら、第4成分を0として加算します。
係数をまとめて
\[
=\frac1{20}V
\begin{bmatrix}
2&1&1&1\\
1&2&1&1\\
1&1&2&1\\
1&1&1&2
\end{bmatrix}
\frac{\{V_i\}^{\tau+\Delta\tau}-\{V_i\}^{\tau}}{\Delta\tau}
\]
対流項
\[
\begin{aligned}
&+V_x\frac1{24}
\begin{bmatrix}
c_{1x}&c_{2x}&c_{3x}&c_{4x}\\
c_{1x}&c_{2x}&c_{3x}&c_{4x}\\
c_{1x}&c_{2x}&c_{3x}&c_{4x}\\
c_{1x}&c_{2x}&c_{3x}&c_{4x}
\end{bmatrix}\{V_i\}\\[6pt]
&+V_y\frac1{24}
\begin{bmatrix}
c_{1y}&c_{2y}&c_{3y}&c_{4y}\\
c_{1y}&c_{2y}&c_{3y}&c_{4y}\\
c_{1y}&c_{2y}&c_{3y}&c_{4y}\\
c_{1y}&c_{2y}&c_{3y}&c_{4y}
\end{bmatrix}\{V_i\}\\[6pt]
&+V_z\frac1{24}
\begin{bmatrix}
c_{1z}&c_{2z}&c_{3z}&c_{4z}\\
c_{1z}&c_{2z}&c_{3z}&c_{4z}\\
c_{1z}&c_{2z}&c_{3z}&c_{4z}\\
c_{1z}&c_{2z}&c_{3z}&c_{4z}
\end{bmatrix}\{V_i\}
\end{aligned}
\]
x軸方向の粘性項と圧力項
\[
\begin{aligned}
&+\frac1{Re}\frac1{36V}
\begin{bmatrix}
c_{1x}c_{1x}&c_{1x}c_{2x}&c_{1x}c_{3x}&c_{1x}c_{4x}\\
c_{2x}c_{1x}&c_{2x}c_{2x}&c_{2x}c_{3x}&c_{2x}c_{4x}\\
c_{3x}c_{1x}&c_{3x}c_{2x}&c_{3x}c_{3x}&c_{3x}c_{4x}\\
c_{4x}c_{1x}&c_{4x}c_{2x}&c_{4x}c_{3x}&c_{4x}c_{4x}
\end{bmatrix}\{V_i\}\\[6pt]
&+\frac1{Re}\frac1{36V}
\begin{bmatrix}
c_{1x}c_{1i}&c_{1x}c_{2i}&c_{1x}c_{3i}&c_{1x}c_{4i}\\
c_{2x}c_{1i}&c_{2x}c_{2i}&c_{2x}c_{3i}&c_{2x}c_{4i}\\
c_{3x}c_{1i}&c_{3x}c_{2i}&c_{3x}c_{3i}&c_{3x}c_{4i}\\
c_{4x}c_{1i}&c_{4x}c_{2i}&c_{4x}c_{3i}&c_{4x}c_{4i}
\end{bmatrix}\{V_x\}\\[6pt]
&-\delta_{xi}\frac1{24}
\begin{bmatrix}
c_{1x}&c_{1x}&c_{1x}&c_{1x}\\
c_{2x}&c_{2x}&c_{2x}&c_{2x}\\
c_{3x}&c_{3x}&c_{3x}&c_{3x}\\
c_{4x}&c_{4x}&c_{4x}&c_{4x}
\end{bmatrix}\{P\}
\end{aligned}
\]
y軸方向の粘性項と圧力項
\[
\begin{aligned}
&+\frac1{Re}\frac1{36V}
\begin{bmatrix}
c_{1y}c_{1y}&c_{1y}c_{2y}&c_{1y}c_{3y}&c_{1y}c_{4y}\\
c_{2y}c_{1y}&c_{2y}c_{2y}&c_{2y}c_{3y}&c_{2y}c_{4y}\\
c_{3y}c_{1y}&c_{3y}c_{2y}&c_{3y}c_{3y}&c_{3y}c_{4y}\\
c_{4y}c_{1y}&c_{4y}c_{2y}&c_{4y}c_{3y}&c_{4y}c_{4y}
\end{bmatrix}\{V_i\}\\[6pt]
&+\frac1{Re}\frac1{36V}
\begin{bmatrix}
c_{1y}c_{1i}&c_{1y}c_{2i}&c_{1y}c_{3i}&c_{1y}c_{4i}\\
c_{2y}c_{1i}&c_{2y}c_{2i}&c_{2y}c_{3i}&c_{2y}c_{4i}\\
c_{3y}c_{1i}&c_{3y}c_{2i}&c_{3y}c_{3i}&c_{3y}c_{4i}\\
c_{4y}c_{1i}&c_{4y}c_{2i}&c_{4y}c_{3i}&c_{4y}c_{4i}
\end{bmatrix}\{V_y\}\\[6pt]
&-\delta_{yi}\frac1{24}
\begin{bmatrix}
c_{1y}&c_{1y}&c_{1y}&c_{1y}\\
c_{2y}&c_{2y}&c_{2y}&c_{2y}\\
c_{3y}&c_{3y}&c_{3y}&c_{3y}\\
c_{4y}&c_{4y}&c_{4y}&c_{4y}
\end{bmatrix}\{P\}
\end{aligned}
\]
z軸方向の粘性項と圧力項
\[
\begin{aligned}
&+\frac1{Re}\frac1{36V}
\begin{bmatrix}
c_{1z}c_{1z}&c_{1z}c_{2z}&c_{1z}c_{3z}&c_{1z}c_{4z}\\
c_{2z}c_{1z}&c_{2z}c_{2z}&c_{2z}c_{3z}&c_{2z}c_{4z}\\
c_{3z}c_{1z}&c_{3z}c_{2z}&c_{3z}c_{3z}&c_{3z}c_{4z}\\
c_{4z}c_{1z}&c_{4z}c_{2z}&c_{4z}c_{3z}&c_{4z}c_{4z}
\end{bmatrix}\{V_i\}\\[6pt]
&+\frac1{Re}\frac1{36V}
\begin{bmatrix}
c_{1z}c_{1i}&c_{1z}c_{2i}&c_{1z}c_{3i}&c_{1z}c_{4i}\\
c_{2z}c_{1i}&c_{2z}c_{2i}&c_{2z}c_{3i}&c_{2z}c_{4i}\\
c_{3z}c_{1i}&c_{3z}c_{2i}&c_{3z}c_{3i}&c_{3z}c_{4i}\\
c_{4z}c_{1i}&c_{4z}c_{2i}&c_{4z}c_{3i}&c_{4z}c_{4i}
\end{bmatrix}\{V_z\}\\[6pt]
&-\delta_{zi}\frac1{24}
\begin{bmatrix}
c_{1z}&c_{1z}&c_{1z}&c_{1z}\\
c_{2z}&c_{2z}&c_{2z}&c_{2z}\\
c_{3z}&c_{3z}&c_{3z}&c_{3z}\\
c_{4z}&c_{4z}&c_{4z}&c_{4z}
\end{bmatrix}\{P\}
\end{aligned}
\]
表面張力項
\[
+\frac{2K^*}{3We}n_iS
\begin{bmatrix}
1\\
1\\
1
\end{bmatrix}
\]
重力項
\[
-g_i^*\frac{V}{4}
\begin{bmatrix}1\\1\\1\\1\end{bmatrix}
\qquad(i=1,2,3)
\]
行列式をまとめると
\[
\begin{aligned}
&={}[C]\frac{\{V_i\}^{\tau+\Delta\tau}-\{V_i\}^{\tau}}{\Delta\tau}
+V_x[C_x]\{V_i\}+V_y[C_y]\{V_i\}+V_z[C_z]\{V_i\}\\[6pt]
&+\frac{1}{Re}[S_{xx}]\{V_i\}+\frac{1}{Re}[S_{xi}]\{V_x\}-\delta_{xi}[H_x]\{P\}\\[6pt]
&+\frac{1}{Re}[S_{yy}]\{V_i\}+\frac{1}{Re}[S_{yi}]\{V_y\}-\delta_{yi}[H_y]\{P\}\\[6pt]
&+\frac{1}{Re}[S_{zz}]\{V_i\}+\frac{1}{Re}[S_{zi}]\{V_z\}-\delta_{zi}[H_z]\{P\}\\[6pt]
&+\frac{2K^*}{3We}n_iS
\begin{bmatrix}1\\1\\1\end{bmatrix}\\[6pt]
&-g_i^*\frac{V}{4}
\begin{bmatrix}1\\1\\1\\1\end{bmatrix}
\qquad (i=1,2,3)
\end{aligned}
\]
行列ごとにまとめると
\[
\begin{aligned}
&={}[C]\frac{\{V_i\}^{\tau+\Delta\tau}-\{V_i\}^{\tau}}{\Delta\tau}\\[6pt]
&+(V_x[C_x]+V_y[C_y]+V_z[C_z])\{V_i\}\\[6pt]
&+\frac{1}{Re}([S_{xx}]+[S_{yy}]+[S_{zz}])\{V_i\}\\[6pt]
&+\frac{1}{Re}\left([S_{xi}]\{V_x\}+[S_{yi}]\{V_y\}+[S_{zi}]\{V_z\}\right)\\[6pt]
&-(\delta_{xi}[H_x]+\delta_{yi}[H_y]+\delta_{zi}[H_z])\{P\}\\[6pt]
&+\frac{2K^*}{3We}n_iS
\begin{bmatrix}1\\1\\1\end{bmatrix}\\[6pt]
&-g_i^*\frac{V}{4}
\begin{bmatrix}1\\1\\1\\1\end{bmatrix}
\qquad (i=1,2,3)\\[6pt]
&={}\begin{bmatrix}0\\0\\0\\0\end{bmatrix}
\end{aligned}
\]
最終的に次式が導出されます。
\[
\begin{aligned}
&[C]\frac{\{V_i\}^{\tau+\Delta\tau}-\{V_i\}^{\tau}}{\Delta\tau}
+(V_x[C_x]+V_y[C_y]+V_z[C_z])\{V_i\}\\[6pt]
&+\frac{1}{Re}([S_{xx}]+[S_{yy}]+[S_{zz}])\{V_i\}\\[6pt]
&+\frac{1}{Re}\left([S_{xi}]\{V_x\}+[S_{yi}]\{V_y\}+[S_{zi}]\{V_z\}\right)\\[6pt]
&-(\delta_{xi}[H_x]+\delta_{yi}[H_y]+\delta_{zi}[H_z])\{P\}\\[6pt]
&+\frac{2K^*}{3We}n_iS
\begin{bmatrix}1\\1\\1\end{bmatrix}
-g_i^*\frac{V}{4}
\begin{bmatrix}1\\1\\1\\1\end{bmatrix}
=\begin{bmatrix}0\\0\\0\\0\end{bmatrix}
\qquad (i=1,2,3)
\end{aligned}
\]
既知の項を右辺に移項します。
\[
\begin{aligned}
\frac{[C]}{\Delta\tau}\{V_i\}^{\tau+\Delta\tau}
&+(V_x[C_x]+V_y[C_y]+V_z[C_z])\{V_i\}^{\tau+\Delta\tau}\\[6pt]
&+\frac{1}{Re}([S_{xx}]+[S_{yy}]+[S_{zz}])\{V_i\}^{\tau+\Delta\tau}\\[6pt]
&+\frac{1}{Re}\left([S_{xi}]\{V_x\}^{\tau+\Delta\tau}
+[S_{yi}]\{V_y\}^{\tau+\Delta\tau}
+[S_{zi}]\{V_z\}^{\tau+\Delta\tau}\right)\\[6pt]
&-(\delta_{xi}[H_x]+\delta_{yi}[H_y]+\delta_{zi}[H_z])\{P\}^{\tau+\Delta\tau}\\[6pt]
&={}\frac{[C]}{\Delta\tau}\{V_i\}^{\tau}
-\frac{2K^*}{3We}n_iS
\begin{bmatrix}1\\1\\1\end{bmatrix}
+g_i^*\frac{V}{4}
\begin{bmatrix}1\\1\\1\\1\end{bmatrix}
\qquad (i=1,2,3)
\end{aligned}
\]
x軸方向の成分は次式となります。
\[
\begin{aligned}
\frac{[C]}{\Delta\tau}\{V_x\}^{\tau+\Delta\tau}
&+(V_x[C_x]+V_y[C_y]+V_z[C_z])\{V_x\}^{\tau+\Delta\tau}\\[6pt]
&+\frac{1}{Re}\left\{
(2[S_{xx}]+[S_{yy}]+[S_{zz}])\{V_x\}^{\tau+\Delta\tau}
+[S_{yx}]\{V_y\}^{\tau+\Delta\tau}
+[S_{zx}]\{V_z\}^{\tau+\Delta\tau}
\right\}
-[H_x]\{P\}^{\tau+\Delta\tau}\\[6pt]
&={}\frac{[C]}{\Delta\tau}\{V_x\}^{\tau}
-\frac{2K^*}{3We}n_xS
\begin{bmatrix}1\\1\\1\end{bmatrix}
+g_x^*\frac{V}{4}
\begin{bmatrix}1\\1\\1\\1\end{bmatrix}
\end{aligned}
\]
y軸方向の成分は次式となります。
\[
\begin{aligned}
\frac{[C]}{\Delta\tau}\{V_y\}^{\tau+\Delta\tau}
&+(V_x[C_x]+V_y[C_y]+V_z[C_z])\{V_y\}^{\tau+\Delta\tau}\\[6pt]
&+\frac{1}{Re}\left\{
[S_{xy}]\{V_x\}^{\tau+\Delta\tau}
+([S_{xx}]+2[S_{yy}]+[S_{zz}])\{V_y\}^{\tau+\Delta\tau}
+[S_{zy}]\{V_z\}^{\tau+\Delta\tau}
\right\}
-[H_y]\{P\}^{\tau+\Delta\tau}\\[6pt]
&={}\frac{[C]}{\Delta\tau}\{V_y\}^{\tau}
-\frac{2K^*}{3We}n_yS
\begin{bmatrix}1\\1\\1\end{bmatrix}
+g_y^*\frac{V}{4}
\begin{bmatrix}1\\1\\1\\1\end{bmatrix}
\end{aligned}
\]
z軸方向の成分は次式となります。
\[
\begin{aligned}
\frac{[C]}{\Delta\tau}\{V_z\}^{\tau+\Delta\tau}
&+(V_x[C_x]+V_y[C_y]+V_z[C_z])\{V_z\}^{\tau+\Delta\tau}\\[6pt]
&+\frac{1}{Re}\left\{
[S_{xz}]\{V_x\}^{\tau+\Delta\tau}
+[S_{yz}]\{V_y\}^{\tau+\Delta\tau}
+([S_{xx}]+[S_{yy}]+2[S_{zz}])\{V_z\}^{\tau+\Delta\tau}
\right\}
-[H_z]\{P\}^{\tau+\Delta\tau}\\[6pt]
&={}\frac{[C]}{\Delta\tau}\{V_z\}^{\tau}
-\frac{2K^*}{3We}n_zS
\begin{bmatrix}1\\1\\1\end{bmatrix}
+g_z^*\frac{V}{4}
\begin{bmatrix}1\\1\\1\\1\end{bmatrix}
\qquad (i=1,2,3)
\end{aligned}
\]
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