Asked by Shangeetha Mahendran
on 19 Dec 2018

I have to get graphs similar to attached file

function pde1

clc; clear; close all

m=1; %cylindrical geometry

R=3e-3; %radius of lumen (m)

dm = 13.04e-6; % TM thickness (m)

r1 =R + dm; %radius of outer surface of membrane (m)

L=1.2; %height of the membrane (m)

Q = 6.5e-9; %volumetric flow rate

D=1.76e-9; %diffusion coefficient of ammonia in liquid m2/s

RT = 2477.6; %J/mol

H = 1.62; %Henry's law constant Pam^3/mol

u0= 285.1; %inflow concentration

zn=10; % grid line z (actually z denoted by t

xn = 10; % grid-steps channel x-axis(radius side)

xmesh = linspace(0,R,xn);

zspan =linspace(0,L,zn); %counter point of length% spatial solution domain (m)

dx = 1/(xn-1);

x = [xmesh]; %x vector

z =[zspan]; %t vector

U_a = Q/3.14/R^2; % average velocity

sol =pdepe(m,@pdefun,@pdeic,@pdebc,xmesh,zspan);

u=sol(:,:,1)

surf(x,z,u)

xlabel('radi')

ylabel('height')

figure

plot(x/R,u(end,:)/u0)

xlabel('radi')

ylabel('concentration')

figure

plot(z/L,u(:, end)/u0)

xlabel('height')

ylabel('c')

figure

hold on

for i =1:zn

plot(x

/R,u(i,:),'.k')

hold off

end

xlabel('position ')

ylabel('concentration in every row')

figure

hold on

for ii =1:xn

plot(z/L,u(:,ii),'.')

hold off

end

xlabel('position ')

ylabel('concentration in every colomn')

%%

function [c,f,s]= pdefun(x,z,u,DuDx)

c = U_a/D;

f = DuDx;

s=0;

end

%% initial condition

function u0 = pdeic(x)

u0 =285.1;

end

%%

function [pl,ql,pr,qr] = pdebc(xl,ul,xr,ur,z)

pl=0;

ql=1;

pr=u0;

qr=1;

end

save('results.mat');

end

Answer by Akshay Khadse
on 27 Dec 2018

Assuming that you are facing difficulty in superimposing graphs, you could try any of the following suggestions:

1) Remove the 'hold off' from inside the 'for' loop. In your code, the 'hold off' during each iteration of 'for' loop causes the previous line to get replaced.

2) You could direclty plot the matrices as described in the following MATLAB Answers Page:

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## 4 Comments

## Stephen Cobeldick (view profile)

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https://www.mathworks.com/matlabcentral/answers/436474-how-to-plot-each-raw-and-each-column-of-the-matrix#comment_652284

## madhan ravi (view profile)

## Direct link to this comment

https://www.mathworks.com/matlabcentral/answers/436474-how-to-plot-each-raw-and-each-column-of-the-matrix#comment_652285

## Shangeetha Mahendran (view profile)

## Direct link to this comment

https://www.mathworks.com/matlabcentral/answers/436474-how-to-plot-each-raw-and-each-column-of-the-matrix#comment_652297

## Shangeetha Mahendran (view profile)

## Direct link to this comment

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