PDE for overall mass transport equation

Dear all

Please help me to solve PDE differential equations. I would like to sovle the function PDE but i can not do it as I would like to. Here is the code I have written. Please help me. Thank you so much.

My incomplete code

% code:

clc;

clear all;

close all;

% Time step

t = 0:120;

% length step

L = 0:30;

% y1 step

y1 = 0:50%;

sol1 = pdepe(t, )

figure(1)

xlabel('Time [min]');

ylabel('canister mass [g]');

plot , )

grid on;

sol2 = pdepe(L,)

figure(2)

xlabel('Length [cm]');

ylabel('canister mass [g]');

plot , )

grid on;

[Torsten]

How are y1 and m1 related ?

[Khai]

Dear Torsten. There is a related between y1 and y1 (ya = 1-y1 ). Please help me to sove it. Thank you so much

[Torsten]

You have a differential equation for m1, and m1 does not appear on the right-hand side, but y1 does. So there must be a relationship between m1 and y1.

[Khai]

There is a relationship between m1 and y1 as shown in below. Please hlpe me to solve it.

[Torsten]

Then differentiate both expressions for m1 with respect to t, insert dm1/dt in the partial differential equation (which now is an expression involving dy1/dt) and use "pdepe" to solve.

Within "pdepe", the coefficient "c" before du/dt will depend on the value of y1 according to the above case distinction.