2-D Transient Heat Transfer Using Surf

Hello,

I have code that I want to plot the heat transfer of a cross section of a Li-ion battery as a function of time. The code runs but keeps giving me errors of frame size and only gives me the final temperature solution. I want it to run from 0 charge to 12 C charge with a discharge current of 45 Amps for 300 seconds.

Here is the code:

%% PARAMETERS

global k e_gen Tinit h alpha

%% RELATIVELY CONSTANT PARAMETERS

cell_capacity = 4.2; % Ah

C_rate = 12;

prompt2 = 'What is the discharge current in Amps? ';

I = input(prompt2); % A, current (discharge)

Tinit = 25;% [=] deg C, initial temperature

V = pi*(0.01085)^2*(0.0702); % [=] m^3, cell volume

R_int = .016;

prompt3 = 'What is the heat transfer coefficient in W/m^2-K? Example: 10 for ambient air, 500 for flowing water. ';

h = input(prompt3);

%% ESTIMATED PARAMETERS

k = 70; % [=] W/m-K, thermal conductivity

Cp = 800;% J/kg-K, specific heat capacity

rho = 2707; % [=] kg/m^3, density

% Value for h taken from Engineering Toolbox: h = 10 for air, 500 for oil

%% CALCULATED PARAMETERS

alpha = k/(rho*Cp);

power = I^2*R_int; % [=] W, power generated by cell

e_gen = power/V; % [=] W/m^3, volumetric heat generation term

total_t = 3600/C_rate; % [=] s, total time

%%%%%%%%%%%%%%%%%%%%%%%%

close all

m = 0; % cylinder geometry

y = linspace(0,.01085,100);

r = linspace(0,0.07,100); % r = 0 to (10.5 mm)

t = linspace(0,total_t,100);

z = zeros(length(r),length(y),length(t));

sol = pdepe(m,@pdex1pde,@pdex1ic,@pdex1bc,r,t);

% Extract the first solution component as T

T = sol(:,:,1);

for total_t = 1:total_t

z(:,:,1:length(total_t)) = T;

end

[x,y] = meshgrid(r,y);

open(obj)

for total_t = 1:length(t)

surfc(r,y,z(:,:,total_t));

xlabel('Height in (m)');

ylabel('R in (m)');

zlabel('Temperature in (C)');

title(num2str(t(total_t),'time = %4.3 (sec)'));

zlim([0 ceil(max(T(:))+1)]);

set(gca,'Fontsize',12);

set(gca,'FontWeight','Bold');

colormap jet;

caxis([25 max(T(:))]);

colorbar;

drawnow

pause(0.1)

f = getframe(gca);

size(f.cdata)

writeVideo(obj,f);

end

close(gca)

close(obj)

% --------------------------------------------------------------------------

function [c,f,s] = pdex1pde(r,t,u,DuDx)

% Main PDE

global alpha k e_gen

c = 1/alpha;

f = DuDx;

s = e_gen/k;

end

% --------------------------------------------------------------------------

function u0 = pdex1ic(r)

% Initial condition

global Tinit

u0 = Tinit;

end

% --------------------------------------------------------------------------

function [pl,ql,pr,qr] = pdex1bc(xl,ul,xr,ur,t)

% Boundary conditions

global h k Tinit

pl = 0;

ql = 1;

pr = h*(ur-Tinit);

qr = k;

end

[Durganshu]

Can you please post your question in a better way? read the MATLAB's guide to how to ask good questions.