All Questions
77
questions
0
votes
0
answers
53
views
Prof A. Stanoyevitch's finite difference based PDE matlab code
Where can one find Prof A. Stanoyevitch's finite difference based PDE matlab code? They have a book on such a topic but can't find the accompanying code.
Is it well received? It's not commonly talked ...
- 317
0
votes
1
answer
95
views
Prof Lawrence Shampine's hpde matlab code
Where can one find Prof Lawrence Shampine's hpde matlab code?
Is it well received? It's not commonly talked about.
- 317
4
votes
0
answers
126
views
FVM for non-regular domain with triangular mesh
Setup
The 1D convection-diffusion equation is given by:
\begin{equation}\tag{1}
\frac{\partial u}{\partial t} + v \frac{\partial u}{\partial x} - \mu \frac{\partial^2 u}{\partial x^2} = 0,
\end{...
- 91
1
vote
0
answers
103
views
Method of lines for a mixed PDE
I am trying to solve the following PDE using the method of lines to discretize space, and then solve it as system of ODEs at each point in space using ODE15s:
subject to
and initial condition $w(z,t=...
- 11
0
votes
0
answers
81
views
How to get damping matrix for structural model in FE analysis
I need to implement in C a method of obtaining transient solution of damped FE models based on modal results for a structural model (imported CAD geometry) defined with hysteretic (structural) damping....
- 1
3
votes
1
answer
189
views
Numerical scheme for the level set equation that solves inverse mean curvature flow problems
I am considering the problem of simulating the evolution of an interface given as a curve in 2D (or surface in 3D) that evolves according to a velocity specified at the interface of the form:
$$\vec{v}...
- 33
0
votes
1
answer
175
views
How do I use pdepe for a first order parabolic PDE with only one boundary condition?
I am trying to use Matlab's pdepe.m to solve the first order parabolic PDE
$$\frac{\partial u}{\partial x}+\frac{\partial u}{\partial x}=x$$
I have not had trouble coding the argument of pdepe @pdefun:...
0
votes
0
answers
81
views
Best approach to solve this system of equations?
I have the following 1D (in space, that is) system of equations I would like to solve:
\begin{equation}
\rho_{fs}\frac{\partial x_{fs}}{\partial t} = h_m\left(W_a - W_{fs}\right) - D_{eff}\left(\...
- 9
1
vote
0
answers
126
views
Discrete laplacian 9 point
I am trying to write a code for 9 point discrete laplacian. I would like to write a matrix and solve the linear system $AU=F$ with gradient conjugate method.
I wrote the matrix this way
...
- 41
3
votes
1
answer
130
views
Upwind scheme with periodic conditions
I am struggling with this assignment.
I have to write an upwind scheme for the following PDE:
$$u_t+a Du=0 \quad\mathrm{on}\;(-1,3)$$
$a$ is said to be positive, the initial condition is $\sin(2\pi x)$...
- 41
0
votes
1
answer
65
views
Numerical solution of PDE with uniform initial condition
I have a PDE like this
$$
\frac{\partial h}{\partial t} = \bigg(\frac{\dot{L}}{L}\bigg)x\frac{\partial h}{\partial x} - \alpha\bigg[h^3\frac{\partial^3 h}{\partial x^3}\bigg]
$$
With boundary and ...
- 73
0
votes
1
answer
145
views
Solving PDE with a non-linear constraint in MATLAB
I am trying to solve a DAE with a non-linear constraint. The governing equations have the following form.
The second equation is a constraint and it must be satisfied everywhere. Is there a way to ...
3
votes
0
answers
173
views
Numerically solving a 6th order non-linear differential equation in Matlab
I've posted yesterday a question about solving a non linear equation : it was not clear so I am reformulating my question.
I am trying to solve a high-order non linear differential equation presented ...
- 33
0
votes
1
answer
137
views
Assembly of the Isoparametric Quadratic load vector in Matlab [duplicate]
I work to solve PDE using FEM in the case P2 on Matlab. I try to correctly assemble load vector using quadratic Lagrange shape functions $$b_i =(f,\phi_i)=\sum_{q=1}^{nq}f(r_q,s_q)*\phi_{i}(r_q,s_q)*...
- 11
1
vote
2
answers
192
views
Continuation of solution to $-\nabla\cdot (k(x,y)\nabla u)=f$
I'm trying to solve the following problem, I had previously opened another discussion for the implementation and well, it seems that it has turned out well, it can be found here.
I need to calculate ...
- 123