Darcy's law

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hasan damaj 2019-12-7

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/495382-darcy-s-law

回答： Hassan Abdullah Saleem 2020-10-12

clc
clear
% Laplace equation
% Define the length of the grid
L  = 5 ;
% Define the Width of the grid
B = 5 ;
nx = 4 ;
ny = 4 ;
dx = 100;
dy =  100;
h=zeros(nx,ny);
amax = 0;
% boundry conditions
h(1,:)  = [ 8.04 , 7.68 , 7.19 , 6.82 ];
h(nx,:) = [ 8.53 , 8.41 , 8.33 , 8.29 ];
h(:,1)  = [ 8.04 , 8.18 , 8.36 , 8.53 ];
h(:,ny) = [ 6.82 , 7.56 , 7.99 , 8.29 ];
while amax <= 0.01
	for j = 2 : nx-1
		for i = 2 : ny-1
			oldval = h(i,j);
			h(i,j) = ( h(i-1,j) + h(i+1,j) + h(i,j-1) + h(i,j+1)/4) ;
			e = abs(h(i,j)) - oldval;
			if e > amax
				amax = e;
			end
		end
	end
end
h

I NEED TO GET TO THE FOLLOWING RESULT

8.04 8.18 8.36 8.53

7.68 7.93 8.19 8.41

7.19 7.68 8.05 8.33

6.82 7.56 7.99 8.29

Can you suggest for me the correction and thank you :)

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hasan damaj 2019-12-11

the equation is correct sir..

hasan damaj 2019-12-11

the while condition is not working with me

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回答（3 个）

Image Analyst 2019-12-7

0
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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/495382-darcy-s-law#answer_405301

在 MATLAB Online 中打开

You're setting up your boundary conditions incorrectly. You're overwriting the corners with different numbers. I think maybe you want this:

% Initialize boundary conditions:
h(1,:)  = [ 8.04 , 7.68 , 7.19 , 8.53];
h(end,:) = [6.82 , 7.56 , 7.99 , 8.29 ];
h(2:3,1)  = [7.68;7.19];
h(2:3,end)  = [8.41; 8.33];
h
% Here h should be
% 8.04          8.18    8.36    8.53
% 7.68           0       0      8.41
% 7.19           0       0      8.33
% 6.82          7.56    7.99    8.29