%ASS 5
clear variables
clc

antal_dagar=10;



Side_length=9; %meter
Surface_velo=3; %m/s
Surface_area=9*9; %m^2
height=24;
length_wood=0.04; %length
length_glass_fibre=0.22; %length
length_chip=0.02; %length
totallength=length_wood+length_glass_fibre+length_chip;
dx=0.01;
points=(totallength/dx);
points_int=int16(points);
T_in=19;
T_out=19; % celcius

h_inner_wall=2.5; %W/m^2*k

convection_velo=3; %meter/sec
time_start_day=6;
point_1=length_wood/dx+1;
point_2=(length_wood+length_glass_fibre)/dx+1;
dt=10; %Second time step
test_number= antal_dagar*86400/dt;

alfa_wood= 1.8814*10^-7; %m2/s
Fo_wood=(alfa_wood*dt)/(dx^2);
K_wood=0.17; %Thermal conductivity
density_wood=545; %Table A.3
epsilon=0.98;  %given in the heat transfer book for hard wood black
Cp_wood=1255; %Specific heat  J/(kg*K)

alfa_glass_fibre=1.497*10^-6;
Fo_glass_fibre=(alfa_glass_fibre*dt)/(dx^2);
K_glass_fibre=0.04; %THermal conductivity Table A.3
Cp_glass_fibre=835; %             J/(kg*K)
density_glass_fibre=2.58;  %density, internet source

alfa_chip=1.2579*10^-7; %internet source
Fo_chip=(alfa_chip*dt)/(dx^2); %internet source
Cp_chip=1590; %J/(kg*K)
K_chip=0.15;
density_chip=525;

sigma=5.67*10^-8;
%density=

Pr=0.709; %heat transfer tables
kine_vi=15.19*10^-6;
Re=(Side_length*Surface_velo)/kine_vi;
%h= nusselts calculation
%h_inner_wall=2.5
k_air=0.0257;
Nu=0.036*(Re)^(4/5)*Pr^(1/3);
h_out=Nu*k_air/Side_length;
T=ones(test_number,points_int+1)*19;

Cp_air=1005; %Assumption 20 degrees room J/kg*K
density_air=1.205; %Assumption 20 degrees room g/dm^3
epsilon_chip= 0.9; %http://www.infrared-thermography.com/material-1.htm

area_wall= 9*2.4;
room_volume= area_wall*9;



for n=1:1:test_number


   rad_curve = 480*sin((pi*((time_start_day+n/(3600/dt)))/12)-(pi/2));
   rad_curve(rad_curve<0)=0;

%negative needs to be zero
temp_curve= 5*sin((pi*(time_start_day+n/(3600/dt))/12)-(pi/2))+19;


   %T(n+1,1)=(((rad_curve+h_out*(temp_curve-T(n,1))+epsilon*sigma*((temp_curve+273.15)^4-(T(n,1)+273.15)^4)+(K_wood/dx)*(T(n,2)-T(n,1)))*dt)/(density_wood*(dx/2)*Cp_wood))+T(n,1);
   T(n+1,1) = ((rad_curve + h_out *(temp_curve - T(n,1)) + epsilon * sigma * ((temp_curve+273.15)^4-(T(n,1)+273.15)^4) + K_wood/dx * (T(n,2) - T(n,1))) * dt)/(density_wood * dx/2 * Cp_wood) + T(n,1);
    for i=2:1:point_1-1

        T(n+1,i) = T(n,i) + Fo_wood * (T(n,i+1) - 2*T(n,i) + T(n,i-1));

    end

    T(n+1,point_1)=T(n,point_1)+dt/Cp_glass_fibre*((K_glass_fibre/dx)*((T(n,(point_1+1))-T(n,point_1))/(density_glass_fibre*dx/2)));

    for i=point_1:1:point_2-1

        T(n+1,i) = T(n,i) + Fo_glass_fibre * (T(n,i+1) - 2*T(n,i) + T(n,i-1));

    end

    T(n+1,point_2)=T(n,point_2)+dt/Cp_chip*((K_chip/dx)*((T(n,(point_2+1))-T(n,point_2))/(density_chip*dx/2)));

    for i=point_2:1:points


        T(n+1,i) = T(n,i) + Fo_chip * (T(n,i+1) - 2*T(n,i) + T(n,i-1));

    end

%T(n+1,28)=(2*dt*(h_inner_wall*(T(n,28+1)-T(n,28)))+(K_chip/dx)*(T(n,28-1)-T(n,28)))/(density_chip*dx*Cp_chip)+T(n,points_int);

% T(n+1,28)=(dt*h_inner_wall*area_wall*(T(n,28)-T(n,29))+(k_innerwall/dx)*area_wall*(T(n,27)-T(n,28))*dt)/(room_volume*density_air)+T(n,28);

T(n+1,28) = ((h_inner_wall *(T(n,29) - T(n,28)) + epsilon_chip * sigma * ((T(n,29)+273.15)^4-(T(n,28)+273.15)^4) + K_chip/dx * (T(n,27) - T(n,28))) * dt)/(density_chip * dx/2 * Cp_chip) + T(n,28);


T(n+1,29)=(h_inner_wall*area_wall*(T(n,28)-T(n,29))*dt)/(room_volume*density_air*Cp_air)+T(n,29);


end

plot (T(:,29));
hold on
plot (T(:,1));