STConvectiveMatrix
Theory
Now we want to compute the space-time convective finite element matrix for following PDE.
∂ u i ∂ t + c k ∂ u i ∂ x k + ⋯ \frac{\partial u_i}{\partial t} + c_k \frac{\partial u_i}{\partial x_k} + \cdots ∂ t ∂ u i + c k ∂ x k ∂ u i + ⋯
We would like to compute the following matrices.
4 M ( I , J , a , b ) = a δ u i I ∫ Q n N I T a c k ∂ N J T b ∂ x k d Q b u i J {}^{4}M(I,J,a,b) = {}^{a}\delta u_{iI} \quad \int_{Q_n} N^I T_a c_k \frac{\partial N^J T_b}{\partial x_k} {dQ} \quad {}^{b}u_{iJ} 4 M ( I , J , a , b ) = a δ u i I ∫ Q n N I T a c k ∂ x k ∂ N J T b d Q b u i J
4 M ( I , J , a , b ) = a δ u i I ∫ Q n c k ∂ N I T a ∂ x k N J T b d Q b u i J {}^{4}M(I,J,a,b) = {}^{a}\delta u_{iI} \quad \int_{Q_n} c_k \frac{\partial N^I T_a}{\partial x_k} N^J T_b {dQ} \quad {}^{b}u_{iJ} 4 M ( I , J , a , b ) = a δ u i I ∫ Q n c k ∂ x k ∂ N I T a N J T b d Q b u i J
Now we want to compute the space-time convective finite element matrix for following PDE.
∂ U ∂ t + ∂ f(U) ∂ x + ∂ g(U) ∂ y + ∂ h(U) ∂ z + ⋯ \frac{\partial \textbf{U}}{\partial t} + \frac{\partial \textbf{f(U)}}{\partial x} + \frac{\partial \textbf{g(U)}}{\partial y} + \frac{\partial \textbf{h(U)}}{\partial z} + \cdots ∂ t ∂ U + ∂ x ∂ f(U) + ∂ y ∂ g(U) + ∂ z ∂ h(U) + ⋯
where U , f , g , h ∈ R m \textbf{U}, \textbf{f}, \textbf{g}, \textbf{h} \in R^m U , f , g , h ∈ R m . In this case we wish to compute the following matrices.
4 M ( I , J , a , b ) = δ a U i I ∫ Q n N I T a ∂ N J T b ∂ x d Q b f i J {}^{4}M(I,J,a,b) = \delta {}^{a} U_{iI} \quad \int_{Q_n} N^I T_a \frac{\partial N^J T_b}{\partial x} {dQ} \quad {}^{b}f_{iJ} 4 M ( I , J , a , b ) = δ a U i I ∫ Q n N I T a ∂ x ∂ N J T b d Q b f i J
4 M ( I , J , a , b ) = δ a U i I ∫ Q n ∂ N I T a ∂ x N J T b d Q b f i J {}^{4}M(I,J,a,b) = \delta {}^{a} U_{iI} \quad \int_{Q_n} \frac{\partial N^I T_a}{\partial x} N^J T_b {dQ} \quad {}^{b}f_{iJ} 4 M ( I , J , a , b ) = δ a U i I ∫ Q n ∂ x ∂ N I T a N J T b d Q b f i J
4 M ( I , J , a , b ) = δ a U i I ∫ Q n N I T a ∂ N J T b ∂ x d Q b g i J {}^{4}M(I,J,a,b) = \delta {}^{a} U_{iI} \quad \int_{Q_n} N^I T_a \frac{\partial N^J T_b}{\partial x} {dQ} \quad {}^{b}g_{iJ} 4 M ( I , J , a , b ) = δ a U i I ∫ Q n N I T a ∂ x ∂ N J T b d Q b g i J
4 M ( I , J , a , b ) = δ a U i I ∫ Q n ∂ N I T a ∂ x N J T b d Q b g i J {}^{4}M(I,J,a,b) = \delta {}^{a} U_{iI} \quad \int_{Q_n} \frac{\partial N^I T_a}{\partial x} N^J T_b {dQ} \quad {}^{b}g_{iJ} 4 M ( I , J , a , b ) = δ a U i I ∫ Q n ∂ x ∂ N I T a N J T b d Q b g i J
4 M ( I , J , a , b ) = δ a U i I ∫ Q n N I T a ∂ N J T b ∂ x d Q b h i J {}^{4}M(I,J,a,b) = \delta {}^{a} U_{iI} \quad \int_{Q_n} N^I T_a \frac{\partial N^J T_b}{\partial x} {dQ} \quad {}^{b}h_{iJ} 4 M ( I , J , a , b ) = δ a U i I ∫ Q n N I T a ∂ x ∂ N J T b d Q b h i J
4 M ( I , J , a , b ) = δ a U i I ∫ Q n ∂ N I T a ∂ x N J T b d Q b h i J {}^{4}M(I,J,a,b) = \delta {}^{a} U_{iI} \quad \int_{Q_n} \frac{\partial N^I T_a}{\partial x} N^J T_b {dQ} \quad {}^{b}h_{iJ} 4 M ( I , J , a , b ) = δ a U i I ∫ Q n ∂ x ∂ N I T a N J T b d Q b h i J
Now we want to compute the space-time convective finite element matrix for following PDE.
∂ u i ∂ t + c k ∂ u i ∂ x k + ⋯ \frac{\partial u_i}{\partial t} + c_k \frac{\partial u_i}{\partial x_k} + \cdots ∂ t ∂ u i + c k ∂ x k ∂ u i + ⋯
We would like to compute the following matrices.
4 M ( I , J , a , b ) = δ a u i I ∫ Q n ∂ N I T a ∂ t c k h ∂ N J T b ∂ x k d Q b u i J {}^{4}M(I,J,a,b) = \delta {}^{a}u_{iI} \int_{Q_n} \frac{ \partial N^I T_a}{\partial t} c_{k}^{h} \frac{\partial N^J T_b}{\partial x_k} {dQ} \quad {}^{b}u_{iJ} 4 M ( I , J , a , b ) = δ a u i I ∫ Q n ∂ t ∂ N I T a c k h ∂ x k ∂ N J T b d Q b u i J
4 M ( I , J , a , b ) = δ a u i I ∫ Q n c k h ∂ N I T a ∂ x k ∂ N J T b ∂ t d Q b u i J {}^{4}M(I,J,a,b) = \delta {}^{a}u_{iI} \int_{Q_n} c_{k}^{h} \frac{\partial N^I T_a}{\partial x_k} \frac{\partial N^J T_b}{\partial t} {dQ} \quad {}^{b}u_{iJ} 4 M ( I , J , a , b ) = δ a u i I ∫ Q n c k h ∂ x k ∂ N I T a ∂ t ∂ N J T b d Q b u i J
Now we want to compute the space-time convective finite element matrix for following PDE.
∂ U ∂ t + ∂ f(U) ∂ x + ∂ g(U) ∂ y + ∂ h(U) ∂ z + ⋯ \frac{\partial \textbf{U}}{\partial t} + \frac{\partial \textbf{f(U)}}{\partial x} + \frac{\partial \textbf{g(U)}}{\partial y} + \frac{\partial \textbf{h(U)}}{\partial z} + \cdots ∂ t ∂ U + ∂ x ∂ f(U) + ∂ y ∂ g(U) + ∂ z ∂ h(U) + ⋯
where U , f , g , h ∈ R m \textbf{U}, \textbf{f}, \textbf{g}, \textbf{h} \in R^m U , f , g , h ∈ R m . In this case we wish to compute the following matrices.
4 M ( I , J , a , b ) = a δ U i I ∫ Q n ∂ N I T a ∂ t ∂ N J T b ∂ x d Q b f i J {}^{4}M(I,J,a,b) = {}^{a}\delta U_{iI} \quad \int_{Q_n} \frac{\partial N^I T_a}{\partial t} \frac{\partial N^J T_b}{\partial x} {dQ} \quad {}^{b}f_{iJ} 4 M ( I , J , a , b ) = a δ U i I ∫ Q n ∂ t ∂ N I T a ∂ x ∂ N J T b d Q b f i J
4 M ( I , J , a , b ) = a δ U i I ∫ Q n ∂ N I T a ∂ x ∂ N J T b ∂ t d Q b f i J {}^{4}M(I,J,a,b) = {}^{a}\delta U_{iI} \quad \int_{Q_n} \frac{\partial N^I T_a}{\partial x} \frac{\partial N^J T_b}{\partial t} {dQ} \quad {}^{b}f_{iJ} 4 M ( I , J , a , b ) = a δ U i I ∫ Q n ∂ x ∂ N I T a ∂ t ∂ N J T b d Q b f i J
4 M ( I , J , a , b ) = a δ U i I ∫ Q n ∂ N I T a ∂ t ∂ N J T b ∂ y d Q b g i J {}^{4}M(I,J,a,b) = {}^{a}\delta U_{iI} \quad \int_{Q_n} \frac{\partial N^I T_a}{\partial t} \frac{\partial N^J T_b}{\partial y} {dQ} \quad {}^{b}g_{iJ} 4 M ( I , J , a , b ) = a δ U i I ∫ Q n ∂ t ∂ N I T a ∂ y ∂ N J T b d Q b g i J
4 M ( I , J , a , b ) = a δ U i I ∫ Q n ∂ N I T a ∂ y ∂ N J T b ∂ t d Q b g i J {}^{4}M(I,J,a,b) = {}^{a}\delta U_{iI} \quad \int_{Q_n} \frac{\partial N^I T_a}{\partial y} \frac{\partial N^J T_b}{\partial t} {dQ} \quad {}^{b}g_{iJ} 4 M ( I , J , a , b ) = a δ U i I ∫ Q n ∂ y ∂ N I T a ∂ t ∂ N J T b d Q b g i J
4 M ( I , J , a , b ) = a δ U i I ∫ Q n ∂ N I T a ∂ t ∂ N J T b ∂ z d Q b h i J {}^{4}M(I,J,a,b) = {}^{a}\delta U_{iI} \quad \int_{Q_n} \frac{\partial N^I T_a}{\partial t} \frac{\partial N^J T_b}{\partial z} {dQ} \quad {}^{b}h_{iJ} 4 M ( I , J , a , b ) = a δ U i I ∫ Q n ∂ t ∂ N I T a ∂ z ∂ N J T b d Q b h i J
4 M ( I , J , a , b ) = a δ U i I ∫ Q n ∂ N I T a ∂ z ∂ N J T b ∂ t d Q b h i J {}^{4}M(I,J,a,b) = {}^{a}\delta U_{iI} \quad \int_{Q_n} \frac{\partial N^I T_a}{\partial z} \frac{\partial N^J T_b}{\partial t} {dQ} \quad {}^{b}h_{iJ} 4 M ( I , J , a , b ) = a δ U i I ∫ Q n ∂ z ∂ N I T a ∂ t ∂ N J T b d Q b h i J
Now we want to compute the space-time convective finite element matrix for following PDE.
∂ U ∂ t + A 1 ∂ U ∂ x + A 2 ∂ U ∂ y + A 3 ∂ U ∂ z + ⋯ \frac{\partial \textbf{U}}{\partial t} + \mathbf{A_1} \frac{\partial \textbf{U}}{\partial x} + \mathbf{A_2} \frac{\partial \textbf{U}}{\partial y} + \mathbf{A_3} \frac{\partial \textbf{U}}{\partial z} + \cdots ∂ t ∂ U + A 1 ∂ x ∂ U + A 2 ∂ y ∂ U + A 3 ∂ z ∂ U + ⋯
where U ∈ R m \textbf{U} \in R^m U ∈ R m , A i ∈ R m × m \mathbf{A_i} \in R^{m \times m} A i ∈ R m × m . In this case we wish to compute the following matrices.
4 M ( I , J , a , b ) = a δ U i I ∫ Q n N I T a [ A 1 ] i j ∂ N J T b ∂ x d Q b f j J {}^{4}M(I,J,a,b) = {}^{a}\delta U_{iI} \quad \int_{Q_n} N^I T_a [ \mathbf{A_1} ]_{ij} \frac{\partial N^J T_b}{\partial x} {dQ} \quad {}^{b}f_{jJ} 4 M ( I , J , a , b ) = a δ U i I ∫ Q n N I T a [ A 1 ] ij ∂ x ∂ N J T b d Q b f j J
4 M ( I , J , a , b ) = a δ U i I ∫ Q n [ A 1 ] j i ∂ N I T a ∂ x N J T b d Q b f j J {}^{4}M(I,J,a,b) = {}^{a}\delta U_{iI} \quad \int_{Q_n} [ \mathbf{A_1} ]_{ji} \frac{\partial N^I T_a}{\partial x} N^J T_b {dQ} \quad {}^{b}f_{jJ} 4 M ( I , J , a , b ) = a δ U i I ∫ Q n [ A 1 ] ji ∂ x ∂ N I T a N J T b d Q b f j J
4 M ( I , J , a , b ) = a δ U i I ∫ Q n N I T a [ A 2 ] i j ∂ N J T b ∂ y d Q b g j J {}^{4}M(I,J,a,b) = {}^{a}\delta U_{iI} \quad \int_{Q_n} N^I T_a [\mathbf{A_2}]_{ij} \frac{\partial N^J T_b}{\partial y} {dQ} \quad {}^{b}g_{jJ} 4 M ( I , J , a , b ) = a δ U i I ∫ Q n N I T a [ A 2 ] ij ∂ y ∂ N J T b d Q b g j J
4 M ( I , J , a , b ) = a δ U i I ∫ Q n [ A 2 ] j i ∂ N I T a ∂ y N J T b d Q b g j J {}^{4}M(I,J,a,b) = {}^{a}\delta U_{iI} \quad \int_{Q_n} [\mathbf{A_2}]_{ji} \frac{\partial N^I T_a}{\partial y} N^J T_b {dQ} \quad {}^{b}g_{jJ} 4 M ( I , J , a , b ) = a δ U i I ∫ Q n [ A 2 ] ji ∂ y ∂ N I T a N J T b d Q b g j J
4 M ( I , J , a , b ) = a δ U i I ∫ Q n N I T a [ A 3 ] i j ∂ N J T b ∂ z d Q b h j J {}^{4}M(I,J,a,b) = {}^{a}\delta U_{iI} \quad \int_{Q_n} N^I T_a [\mathbf{A_3}]_{ij} \frac{\partial N^J T_b}{\partial z} {dQ} \quad {}^{b}h_{jJ} 4 M ( I , J , a , b ) = a δ U i I ∫ Q n N I T a [ A 3 ] ij ∂ z ∂ N J T b d Q b h j J
4 M ( I , J , a , b ) = a δ U i I ∫ Q n [ A 3 ] j i ∂ N I T a ∂ z N J T b d Q b h j J {}^{4}M(I,J,a,b) = {}^{a}\delta U_{iI} \quad \int_{Q_n} [\mathbf{A_3}]_{ji} \frac{\partial N^I T_a}{\partial z} N^J T_b {dQ} \quad {}^{b}h_{jJ} 4 M ( I , J , a , b ) = a δ U i I ∫ Q n [ A 3 ] ji ∂ z ∂ N I T a N J T b d Q b h j J
The shape of each 4 M ( : , : , a , b ) {}^{4}M(:,:,a,b) 4 M ( : , : , a , b ) is ( N N S × m , N N S × m ) (N_{NS} \times m, N_{NS} \times m) ( N NS × m , N NS × m ) . In this case there will be coupling between different components of U \mathbf{U} U . This coupling is due to A i \mathbf{A_i} A i . The structure of any of the above 4 M {}^{4}\mathbf{M} 4 M is given as
4 M ( : , : , a , b ) = [ M 11 ⋯ M 1 m ⋮ ⋱ ⋮ M m 1 ⋯ M m m ] {}^{4}\mathbf{M}(:,:,a,b) =
\begin{bmatrix}
\mathbf{M_{11}} & \cdots & \mathbf{M_{1m}} \\
\vdots & \ddots & \vdots \\
\mathbf{M_{m1}} & \cdots & \mathbf{M_{mm}} \\
\end{bmatrix} 4 M ( : , : , a , b ) = M 11 ⋮ M m1 ⋯ ⋱ ⋯ M 1m ⋮ M mm
Each M i j \mathbf{M_{ij}} M ij has shape ( N n s × N n s ) (N_{ns} \times N_{ns}) ( N n s × N n s ) .
Now we want to compute the space-time convective finite element matrix for following PDE.
∂ U ∂ t + A 1 ∂ U ∂ x + A 2 ∂ U ∂ y + A 3 ∂ U ∂ z + ⋯ \frac{\partial \textbf{U}}{\partial t} + \mathbf{A_1} \frac{\partial \textbf{U}}{\partial x} + \mathbf{A_2} \frac{\partial \textbf{U}}{\partial y} + \mathbf{A_3} \frac{\partial \textbf{U}}{\partial z} + \cdots ∂ t ∂ U + A 1 ∂ x ∂ U + A 2 ∂ y ∂ U + A 3 ∂ z ∂ U + ⋯
where U ∈ R m \textbf{U} \in R^m U ∈ R m , A i ∈ R m × m \mathbf{A_i} \in R^{m \times m} A i ∈ R m × m . In this case we wish to compute the following matrices.
4 M ( I , J , a , b ) = a δ U i I ∫ Q n ∂ N I T a ∂ t [ A 1 ] i j ∂ N J T b ∂ x d Q b f j J {}^{4}M(I,J,a,b) = {}^{a}\delta U_{iI} \quad \int_{Q_n} \frac{\partial N^I T_a}{\partial t} [ \mathbf{A_1} ]_{ij} \frac{\partial N^J T_b}{\partial x} {dQ} \quad {}^{b}f_{jJ} 4 M ( I , J , a , b ) = a δ U i I ∫ Q n ∂ t ∂ N I T a [ A 1 ] ij ∂ x ∂ N J T b d Q b f j J
4 M ( I , J , a , b ) = a δ U i I ∫ Q n [ A 1 ] j i ∂ N I T a ∂ x ∂ N J T b ∂ t d Q b f j J {}^{4}M(I,J,a,b) = {}^{a}\delta U_{iI} \quad \int_{Q_n} [ \mathbf{A_1} ]_{ji} \frac{\partial N^I T_a}{\partial x} \frac{\partial N^J T_b}{\partial t} {dQ} \quad {}^{b}f_{jJ} 4 M ( I , J , a , b ) = a δ U i I ∫ Q n [ A 1 ] ji ∂ x ∂ N I T a ∂ t ∂ N J T b d Q b f j J
4 M ( I , J , a , b ) = a δ U i I ∫ Q n ∂ N I T a ∂ t [ A 2 ] i j ∂ N J T b ∂ y d Q b g j J {}^{4}M(I,J,a,b) = {}^{a}\delta U_{iI} \quad \int_{Q_n} \frac{\partial N^I T_a}{\partial t} [\mathbf{A_2}]_{ij} \frac{\partial N^J T_b}{\partial y} {dQ} \quad {}^{b}g_{jJ} 4 M ( I , J , a , b ) = a δ U i I ∫ Q n ∂ t ∂ N I T a [ A 2 ] ij ∂ y ∂ N J T b d Q b g j J
4 M ( I , J , a , b ) = a δ U i I ∫ Q n [ A 2 ] j i ∂ N I T a ∂ y ∂ N J T b ∂ t d Q b g j J {}^{4}M(I,J,a,b) = {}^{a}\delta U_{iI} \quad \int_{Q_n} [\mathbf{A_2}]_{ji} \frac{\partial N^I T_a}{\partial y} \frac{\partial N^J T_b}{\partial t} {dQ} \quad {}^{b}g_{jJ} 4 M ( I , J , a , b ) = a δ U i I ∫ Q n [ A 2 ] ji ∂ y ∂ N I T a ∂ t ∂ N J T b d Q b g j J
4 M ( I , J , a , b ) = a δ U i I ∫ Q n ∂ N I T a ∂ t [ A 3 ] i j ∂ N J T b ∂ z d Q b h j J {}^{4}M(I,J,a,b) = {}^{a}\delta U_{iI} \quad \int_{Q_n} \frac{\partial N^I T_a}{\partial t} [\mathbf{A_3}]_{ij} \frac{\partial N^J T_b}{\partial z} {dQ} \quad {}^{b}h_{jJ} 4 M ( I , J , a , b ) = a δ U i I ∫ Q n ∂ t ∂ N I T a [ A 3 ] ij ∂ z ∂ N J T b d Q b h j J
4 M ( I , J , a , b ) = a δ U i I ∫ Q n [ A 3 ] j i ∂ N I T a ∂ z ∂ N J T b ∂ t d Q b h j J {}^{4}M(I,J,a,b) = {}^{a}\delta U_{iI} \quad \int_{Q_n} [\mathbf{A_3}]_{ji} \frac{\partial N^I T_a}{\partial z} \frac{\partial N^J T_b}{\partial t} {dQ} \quad {}^{b}h_{jJ} 4 M ( I , J , a , b ) = a δ U i I ∫ Q n [ A 3 ] ji ∂ z ∂ N I T a ∂ t ∂ N J T b d Q b h j J
The shape of each 4 M ( : , : , a , b ) {}^{4}M(:,:,a,b) 4 M ( : , : , a , b ) is ( N N S × m , N N S × m ) (N_{NS} \times m, N_{NS} \times m) ( N NS × m , N NS × m ) . In this case there will be coupling between different components of U \mathbf{U} U . This coupling is due to A i \mathbf{A_i} A i . The structure of any of the above 4 M {}^{4}\mathbf{M} 4 M is given as
4 M ( : , : , a , b ) = [ M 11 ⋯ M 1 m ⋮ ⋱ ⋮ M m 1 ⋯ M m m ] {}^{4}\mathbf{M}(:,:,a,b) =
\begin{bmatrix}
\mathbf{M_{11}} & \cdots & \mathbf{M_{1m}} \\
\vdots & \ddots & \vdots \\
\mathbf{M_{m1}} & \cdots & \mathbf{M_{mm}} \\
\end{bmatrix} 4 M ( : , : , a , b ) = M 11 ⋮ M m1 ⋯ ⋱ ⋯ M 1m ⋮ M mm
Each M i j \mathbf{M_{ij}} M ij has shape ( N n s × N n s ) (N_{ns} \times N_{ns}) ( N n s × N n s ) .
Now consider the following terms in a pde.
A 0 ∂ U ∂ t + A 1 ∂ U ∂ x + A 2 ∂ U ∂ y + A 3 ∂ U ∂ t + ⋯ \mathbf{A_0} \frac{\partial U}{\partial t} + \mathbf{A_1} \frac{\partial U}{\partial x} + \mathbf{A_2} \frac{\partial \mathbf{U}}{\partial y} + \mathbf{A_3} \frac{\partial U}{\partial t} + \cdots A 0 ∂ t ∂ U + A 1 ∂ x ∂ U + A 2 ∂ y ∂ U + A 3 ∂ t ∂ U + ⋯
4 M ( I , J , a , b ) = a δ U i I ∫ Q n [ A 0 ] k i ∂ N I T a ∂ t [ A 1 ] k j ∂ N J T b ∂ x d Q b f j J {}^{4}M(I,J,a,b) = {}^{a}\delta U_{iI} \quad \int_{Q_n} [ \mathbf{A_0}]_{ki} \frac{\partial N^I T_a}{\partial t} [ \mathbf{A_1} ]_{kj} \frac{\partial N^J T_b}{\partial x} {dQ} \quad {}^{b}f_{jJ} 4 M ( I , J , a , b ) = a δ U i I ∫ Q n [ A 0 ] ki ∂ t ∂ N I T a [ A 1 ] kj ∂ x ∂ N J T b d Q b f j J
4 M ( I , J , a , b ) = a δ U i I ∫ Q n [ A 1 ] k i ∂ N I T a ∂ x [ A 0 ] k j ∂ N J T b ∂ t d Q b f j J {}^{4}M(I,J,a,b) = {}^{a}\delta U_{iI} \quad \int_{Q_n} [ \mathbf{A_1} ]_{ki} \frac{\partial N^I T_a}{\partial x} [\mathbf{A_0}]_{kj} \frac{\partial N^J T_b}{\partial t} {dQ} \quad {}^{b}f_{jJ} 4 M ( I , J , a , b ) = a δ U i I