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# Bill Greene

Last seen: 23 days ago Active since 2014

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Hello everyone I hope you are all doing well. Please I have a concern about the coupling of an ODE and an EDP.
I looked at your mathematical description of this problem.Since T is a function of z, V and u are also functions of z. So you re...

4 months ago | 0

How to couple interface of two domains in MATLAB?
As I said, I believe that the expression for S in your definition of the problem is not correct and your explanation did not rea...

5 months ago | 0

Computing temperature of a fluid inside a cylinder using PDEPE
I have written a 1D PDE solver that has an input syntax similar to pdepe but has some additional enhancements including the cap...

6 months ago | 1

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pdepe extract intermediate values
I have written a PDE solver, pde1dm, that has some similarities to pdepe and accepts the same input syntax as pdepe. Most input ...

7 months ago | 0

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Solving partial differential equations using pdesolver
First, in your call to pdepe, you have the t and z arguments switched. It should be sol=pdepe(m,@pde1, @pde1ic, @pde1BC,z,t); ...

9 months ago | 0

Submitted

pde1dM
pde1dm is a 1D PDE solver that supports high order interpolation functions, coupled ODE and is compatible with pdepe input synta...

pdepe help! The solution gives 0...
If you are solving a PDE with either cylindrical symmetry (m=1, your case) or spherical symmetry (m=2), and your left boundary ...

10 months ago | 0

Pdepe: Spatial discretization has failed. Discretization supports only parabolic and elliptic equations, with flux term involving spatial derivative.
Your definition of the input arguments for the boundary condition function is incorrect. Replace, function [pl,ql,pr,qr] = pde...

12 months ago | 0

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Solving coupled set of PDEs and ODEs for 1D-problem using pde1dM
Because your equation (2) is a PDE and not an ODE (as I pointed out in your previous post), it will be quite challenging to sol...

1 year ago | 0

Why does pdepe throw an error depending on boundary condition parameters?
Interesting. The ODE solver(ode15s) is numerically approximating the iteration matrix for the PDE and, due to roundoff er...

1 year ago | 0

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How to deal these type of errors from pdepe? "Error in pdepe/pdeodes (line 359)"
Yes, in my example, the M-matrix was constant but the same idea applies if M is a function of x or the dependent variables. The ...

1 year ago | 0

How to deal these type of errors from pdepe? "Error in pdepe/pdeodes (line 359)"
pdepe does not accept a non-diagonal mass matrix. But often you can deal with this by calculating the inverse of the mass matrix...

1 year ago | 0

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Why does solving the heat equation with MATLAB (pdepe) yield a completely different result than the Heisler chart (analytical solution)?
I referred to section 5.5 of Bergman (the source of your pdf file) and wrote a function that computes the solution the Heisler c...

1 year ago | 0

PDEPE: Unable to meet integration tolerances without reducing the step size below the smallest value allowed
I have occasionally seen similar problems with pdepe in the past. I have written a PDE solver that has input similar to pdepe...

2 years ago | 0

Solving a system a coupled ODE and PDE
The error message is caused by your definition of the ode function: function [dydt] = ode_syst2(t, Tg, Ts, Fig, Fis) The defin...

2 years ago | 0

Appropriate method for solving coupled pdes
Yes, although it is true that the documentation for pdepe describes it as a solver for parabolic systems, it can often obtain...

2 years ago | 2

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Solving PDEs with mass conservation
I don't know how to integrate the dependent variables using pdepe. However, I have written a PDE solver with an input syntax sim...

2 years ago | 0

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Pdepe: Spatial discretization has failed. Discretization supports only parabolic and elliptic equations, with flux term involving spatial derivative.
The boundary conditions for your second PDE are invalid. These should work: pl = [0; 0]; ql = [1; 1]; pr = [ur(1)-cAO; 0]; q...

2 years ago | 1

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A system of PDEs which have one PDE with a spatial variable fixed term, u(x0, t)
pdepe is not really designed to handle systems of coupled PDE and ODE. However, I have written a PDE solver for MATLAB that has ...

2 years ago | 0

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Spatial discretization has failed. Discretization supports only parabolic and elliptic equations, with flux term involving spatial derivative.
Your boundary conditions for u2 (q=0, p=0 at each end) are not valid. The second equation in your system (u2_t=...) is, in fact...

2 years ago | 0

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Gas-Solid Reaction Modeling with Random Pore Model. Pdepe: Spatial discretization has failed. Discretization supports only parabolic and elliptic equations, with flux term involving spatial derivative.
Your right-end boundary conditions are invalid. Possibly you want: pr=[ur(1)-1 0]'; qr =[0 1]' ;

2 years ago | 1

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How to define a step function as input BC in pdepe?
Here is the way you want to define such a BC: if(t>=50) pl = [ul(1);0]; else pl = [ul(1)-10;0]; end One thing you ha...

2 years ago | 0

PDE with time-dependent boundary conditions
I do not believe it is possible to solve this problem with pdepe. However I have written a one-dimensional PDE solver which i...

2 years ago | 0

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I have developed a PDE solver, pde1dM, that Ibelieve can solve your coupled PDE/ODE system. The solver runs in MATLAB and is s...

2 years ago | 1

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Solve heat equation with source term
T and m are referred to as dependent variables, not independent; x and t are the independent variables. This Example shows how t...

2 years ago | 0

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Unable to meet integration tolerances
Your equations have a fundamental error. Just calculate the "s" term along the length at the initial temperature and the problem...

2 years ago | 0

How to solve PDE problem
Your PDE can replaced by these two PDE which is a form acceptable to pdepe. However, pdepe, or in fact any numerical method,...

2 years ago | 1

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Solving second order PDE
The reason that pdepe imposes a boundary condition of the flux equal zero at the center is that this is required for the proble...

2 years ago | 0

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PDEPE: Unable to meet integration tolerances without reducing the step size below the smallest value allowed at time t.
You are trying to solve a system of ODE which is something pdepe is not designed for. Specifically, the pdepe documentation says...

2 years ago | 0

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1D Fourier equation with temperature dependent thermal properties
function [c,f,s] = pdex1pde(x,t,T,dudx,diffr,Tfront) diffr=3.34E-10*T^4 - 9.37E-07*T^3 + 9.38E-04*T^2 - 4.80E-01*T + 2.09E+02; ...

2 years ago | 0