I want to solve the following equation: h(x) = -(D+a*(D/RT)*o*C)dc/dx % D, a, R,T, o are parameters %Boundary conditions: h(0,t)=h(w,t) = C_sat; %Initial conditions: c(x,0)=0;

Solving nonlinear ordinary differential equations

darova 2020-6-26

What about bvp4c?

bbah 2020-6-26

how would it look like for this equation ? i need for that a system of first order equations. How do i get that ?

bbah 2020-6-26

The equation is time indipendent actually. Sorry about that

Ameer Hamza 2020-6-26

Do you just a single equation or multiple equations? What is h(x)? Can you attach the equations in mathematical form?

bbah 2020-6-28

Hello. This is the equation i want to solve. It is steady state so no time dependency is given and the parameters D,alpha, R,T and Omega are given.

The initial condition is:

and the boundary Conditions are: h(0,t) = h(w,t) = 1

darova 2020-6-29

This is not ODE (ordinary diff equation), it's PDE (partial diff equation)

You have more than one (two) variables. YOu have two uknown functions (c and h). But i see only one equation? Where is the second one?

bbah 2020-6-29

that is why i am confused too. h should be the flux of the diffusion of c into a body and there is no second equation.

darova 2020-6-29

One equation - one uknown function

bbah 2020-6-29

what if h = c/c^0 ?

darova 2020-6-29

it means h = c (the same function)

bbah 2020-7-2

sorry for the later response. I think the final equation to be solved is this.

The flux needs to be implemented into the mass balance equation leading to this equation in 1D:

alpha, omega, D, R and T are known ant the boundary conditions are:

c(0,t)=c(w,t) = e.g. 1000 for t(0,t_end)

initial condition

c(x,0) = 0, for x(0,w);

i hope you can help me with this equation

darova 2020-7-2

What about method of lines?