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76 lines
1.7 KiB
76 lines
1.7 KiB
11 years ago
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%for blog: take pictures of graphs of inside and outsite tempurature vs
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%time and oven temperature, also temperature vs radius of a properly cooked turkey.
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tic
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init=0;
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if init == 0
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clear all
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weight = 15/2.2;%lbs
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density = 800;
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% r0=.15;
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r0 = (weight/density/4*3/pi)^(1/3);
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deltar=r0/30;
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r=[deltar*1:deltar:r0];
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alpha = .412/2800/1000;
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h=9; %nusselt number
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k=.412+r*0;
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% weight = r0^3*4*pi/3*density;
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Tinf=600;
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Ti=20;
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T=Ti+r*0;
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waterlost=r*0;
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% T(end)=T(end)+1;
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end
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deltat = .1;
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time=.6*60*60/deltat;%minutes
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Tcenterlog=zeros(1,time);
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Tlog=Tcenterlog;
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for i = 1:time
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dTtemp = (T(3:end)-T(1:end-2))./(2*deltar); %only works if r is linear
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dTdr= [(T(2)-T(1))/deltar, dTtemp, (T(end)-T(end-1))/deltar];
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% dTdr = diff(T)./diff(r);
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% dTdr(end+1)=dTdr(end);
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dTdr(end)= h*(Tinf-T(end))/k(end);
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parenthesis=dTdr.*r.^2;
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dPtemp = (parenthesis(3:end)-parenthesis(1:end-2))./(2*deltar); %again, linear only
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dPdr = [(parenthesis(2)-parenthesis(1))/deltar, dPtemp, (parenthesis(end)-parenthesis(end-1))/deltar];
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% dPdr = diff(parenthesis)./diff(r);
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% dPdr(end+1) = dPdr(end);
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% % if kout > k(end)
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% % k(end)=(kout-k(end))/3+k(end);
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% % end
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% kout=h*(Tinf-T(end))/dTdr(end);
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% k(end)=kout;
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alpha = k/2800/density;
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dTdt=alpha.*dPdr./r.^2;
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% dTdt(1)=dTdt(1)/2;
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T=T+dTdt*deltat;
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waterlost=waterlost+(10.^((T-20)/80)-1)/10;
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% Tcenterlog(i)=T(1);
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% Tlog(i)=T(end);
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end
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figure(1)
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plot(r,(T*1.8+32))
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figure(2)
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plot(r,waterlost)
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% cooktime=[1:time]*deltat/3600;
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% figure(2)
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% hold on
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% plot(cooktime,Tcenterlog*1.8+32)
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% plot(cooktime,Tlog*1.8+32)
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% toc
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