124 lines
2.8 KiB
Matlab
Executable File
124 lines
2.8 KiB
Matlab
Executable File
%Master 441 Code
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%all alfas in DEGREES!
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%by ascorrea
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function master441()
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diary
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datafile=input('Input data file: \nNote: You must delete the header before using \n:','s');
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[variablenames, variablevalues]=textread(datafile, '%s %f');
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for k = 1:length(variablenames)
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eval([variablenames{k} '= variablevalues(k);']);
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end
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i=1;
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for sref=100:100:6000
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AR=wingspan^2/sref;
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%CRUISE------------------------------------------------------------------]
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cd0_cruise=findcd0(c_f, M_cruise, sref, swet);
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cLreq_cruise=findcLrequired(alt_cruise, sref, M_cruise, weight_cruise);
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alphareq_cruise=findalpharequired(cLalpha_cruise, cL0, cLreq_cruise);
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cD_cruise=findcD(AR, efficiency, cd0_cruise, cLreq_cruise, cd_correction);
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eloverdee_cruise=cLreq_cruise/cD_cruise;
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cM_cruise=cMalpha_cruise*alphareq_cruise+cM0;
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plotS(i)=sref;
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plotLD(i)=eloverdee_cruise;
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i=i+1;
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end
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plot(plotS, plotLD)
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fprintf('Max L/D: %f at AR: %f\n', max(plotLD), plotS(max(plotLD)==plotLD));
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end
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function q=findcd0(c_f, M, sref, swet)
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if M>.7
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c_f=c_f*(1-.09*M^2);
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end
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q=c_f*(swet/sref);
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end
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function q=findcLalpha(AR, M, clalpha, sweep, sex, sref, doverb)
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%ascorrea
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betasquared=1-M^2;
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beta=sqrt(betasquared);
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eta=clalpha/(2*pi/beta);
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numer=2*pi*AR;
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denom1=(AR^2*beta^2)/eta^2;
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denom2=(tand(sweep)^2/betasquared);
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denom=2+sqrt(4+denom1*(1+denom2));
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F=1.07*(1+doverb)^2;
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cLalpha=(numer/denom)*(sex/sref)*F;
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q=cLalpha;
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end
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function finddragpolar(cd0, cl_alfa, cL0, sweep_LE, ar, cd_correction, filename)
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alphadeg=[-12:2];
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% alpha=(pi/180)*(alphadeg);
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alpha=alphadeg;
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cL_alfa=cl_alfa*(ar/(ar+(2*(ar+4)/(ar+2))));
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for i=1:length(alpha)
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C_L(i)=cL_alfa*(alpha(i))+cL0;
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e=4.61*(1-.045*ar^.68)*cosd(sweep_LE)^.15-3.1;
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cd_i(i)=C_L(i)^2/(pi*ar*e);
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C_d(i)=cd0+cd_i(i)+cd_correction;
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end
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graphname='Drag Polar';
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hold on
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axisX0=linspace(0,max(cd));
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axisY0=zeros(1,length(axisX0));
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plot(axisX0, axisY0,'k--');
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plot(C_d, C_L);
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plot(C_d, C_L, '.');
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title(graphname);
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xlabel('C_d');
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ylabel('C_L');
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axis([0, .04, -1, 1.5]);
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% for i=1:length(alphadeg)
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% alphalabel=num2str(alphadeg(i));
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% label=[' \alpha =' alphalabel];
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% text(C_d(i), C_L(i), label)
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% end
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print ('-dtiff', filename)
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close(1)
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end
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function q=findcLrequired(alt, s, v_mach, lift)
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if alt < 36152
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temp=59-.00356*alt;
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press=2116*((temp+459.7)/518.6)^5.256;
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elseif alt < 82345
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temp=-70;
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press=473.1*exp(1.73-.000048*alt);
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else
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print('Program Not Valid for given altitude')
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end
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density=press/(1718*(temp+459.7));
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v_fps=v_mach*sqrt(1.4*1718*(temp+459.7));
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q=.5*density*v_fps^2;
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q=lift/(q*s);
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end
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function q=findalpharequired(cLalpha, cL0, cLrequired)
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q=(cLrequired-cL0)/cLalpha;
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end
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function q=findcD(ar, e, cd0, C_L, cd_correction)
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% e=4.61*(1-.045*ar^.68)*cosd(sweep_LE)^.15-3.1;
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cd_i=C_L^2/(pi*ar*e);
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cd_i=C_L^2/(pi*ar*e);
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q=cd0+cd_i+cd_correction;
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end |