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I have divergent geometry, where my longitudinal coordinate is:

z=1:-0.001:0;

Wall of the pipe is defined with this law:

ri=0.7;

R=ri-z*(ri-1);

and ri is inlet radius of the pipe (when z=0), outlet radius is 1 (it means when z=1).

I need to define radius, which will be transverzal coordinate r, it need to go from -R(z) to R(z) for one value of z, but I need to have all values of z. It means that R is not constant, and it is possible to have different number of points at different values of z. Is it possible so solve this for the same number of points in every cross section, and to have r as matrix? Or is it possible to solve it with different number of points in every cross section?

Later I need to calculate D, will D also be matrix?

D=r.*r-R(z).*R(z)ma

I have tried this, and all does not work:

r=[0:R];

r=[0:R(:,0);

0:R(:,1)];...

r=-R:R;

Eugenio Grabovic
on 29 Jan 2019

I maybe understood what you're asking for:

k = 100; % number of transversal discretization

ri = 0:0.7/k:0.7;

i = 0;

for z=1:-0.001:0;

i = i + 1;

R(i,:) = ri-z*(ri-1); % storing the radius values in rows (each row is computed for a different z)

end

About the "D" computation i don't know what "ma" is, sorry.

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