need help with mass transfer modelling

Hi guys,

It would be great if someone can help me with this. I am quite new to modelling, I am trying to model this mass transfer equation

dx/dt=K(C*-x)

x is dissolved CO2 in molten carbonate

C* is solubility of CO2 in molten in the equilibrium

So I am trying to get a plot of CL with following conditions

C*= 150 : 250

t= 0 to 1200

k =0.02

thanks

my function code is

function f= ODEfun(x,t)
 for C=(150:250)
     k=0.05;
     dxdt=k*(C-x);
      f=[dxdt];
 end
end

% I did the below code in separate file where I called the function
tspan= [0 1200];
x=0; %initial condition
[v y]= ode45(@ODEfun,tspan, x);
plot(v,y);

[Sam Chak]

@AL SIAM SIDDIQUE

C has many values.

Why not writing out the first few equations in math notations?

It helps to understand how to translate that into MATLAB code.

Answer 1

[Alan Stevens]

Here's one way of doing it:

% You need to do the time integration for each C separately 

C = 150:50:250;  % Choose your own values of C 

tspan = 0:10:1200;
x0 = 0;
lgnd = [];
% Loop through C values 
for i = 1:numel(C)
  
    [t, X] = ode45(@(t,x)ODEfn(t,x,C(i)), tspan, x0, C(i));
    
    plot(t,X)
    hold on
end
grid
xlabel('time'), ylabel('x')

function dxdt = ODEfn(~ ,x, C)
         k = 0.05;
         dxdt(:,1) = k*(C-x);
end

[AL SIAM SIDDIQUE]

thank you so much.