You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 

76 lines
1.7 KiB

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