31 lines
780 B
Matlab
31 lines
780 B
Matlab
Rlam = 10.^(4:0.05:7);
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Rturb = 10.^(4:0.05:8);
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Rcrit = 539154;
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Rtrans = 10.^(5:0.05:8);
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Rtrans = [Rcrit Rtrans(find(Rtrans > Rcrit))];
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Rs=3e-6;
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Lr=1.0;
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Rcrit=[51*(Rs/Lr)^(-1.039) 1e8];
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critical = 0.032*(Rs/Lr)^(0.2) * [1 1];
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Rcrit
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laminar = 1.328./sqrt(Rlam);
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turbulent = 1./(1.50*log(Rturb)-5.6).^2;
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transitional = 1./((1.50*log(Rtrans)-5.6).^2) - 1700./Rtrans;
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figure;
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loglog(Rlam,laminar,'k-.',Rturb,turbulent,'k--',Rtrans,transitional,'k:',Rcrit,critical,'k-');
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axis([1e4 1e8 0.0005 0.02]);
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xlabel('Reynolds number');
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ylabel('Skin friction coefficient');
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legend('Laminar','Turbulent','Transitional','Roughness-limited');
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set(gcf, 'PaperPositionMode', 'manual');
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set(gcf, 'PaperUnits', 'centimeters');
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set(gcf, 'PaperPosition', [2 2 15 7.5]);
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print('skinfriction.eps');
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