shouldn't there be two parallel lines on my plot?

clear,clc,clf
format long
Q=3.3;
%gamma=8.43 kN/m3 = 859.62076503 Kg/m3 (*1000/9.81)
rouh=859.62076503;
g=9.81;
Gamma=(rouh.*g);
Zs=0;
Ze=0;
L=1285000;
Ks=(0.000045);
Er=(1.*10.^-8);
viscosity=(3.83.*10.^-3);
% material grade X70
strength= 482000000;
%API 5L
Do=[1.016 1.06682 1.1176 1.1684 1.2192]
V=((4.*Q)./(pi.*Do.^2))
Re=(V.*Do./viscosity)
Fo=0.01;
for I=0:1:10^6;
    Fn=(1./(-4.*log10((Ks./(3.71.*Do))+((1.26)./(Re.*sqrt(Fo)))))).^2;
    E=abs((Fn-Fo)/Fn);
    if  E<=Er;
        Fn=Fn(end),display(E),break,
    end
    if E>Er;
        Fo=Fn;
    end
end
Hloss=((Fn.*L.*Q.^2)./(12.*Do.^5))
Hpump=Hloss+Ze-Zs
%calculating Hloss every 100000M
HLC=1:128500:1285000;
for i=1:1:length(HLC);
    HlossN=((Fn.*HLC(i).*Q.^2)./(12.*Do.^5))
    TEL(i,:)=(Hpump-HlossN+Zs)
    HGL(i,:)=(TEL(i,:)-((V.^2)./(2.*g)))
    Pe=Gamma.*(HGL-Ze);
    T=((Pe(i).*Do)./(2.*strength))
end
for ii=1:1:length(Do)
    subplot(3,3,ii),
    plot(HLC,TEL(:,ii),HLC,HGL(:,ii))
    xlabel('HLC')
    ylabel('HGL & TEL')
end

Answer 1

[Rik]

There actually are two parallel lines, but you need to zoom in quite a lot.

If you have a look at the output of the line below, you'll notice that there is not even a percent difference between the two.

TEL(:,ii)./HGL(:,ii)

[omar mahallawy]

i feel so stupid right now!

gosh, thank you soo much

life saver!