clear; clc; //Example9.2[Cooling of a Plate in different orientaions] L=0.6;//side of square plate[m] T_surr=30;//[degree Celcius] Tp=90;//Temp of plate[degree Celcius] Tf=(Tp+T_surr)/2;//Film temperature[degree Celcius] //Properties of air at Tf k=0.02808;//[W/m.degree Celcius] Pr=0.7202;//Prandtl number nu=1.896*10^(-5);//Kinematic viscosity[m^2/s] b=1/(Tf+273);//[K^-1] g=9.81;//Acc due to gravity[m/s^2] //Solution (a) Lc_a=L;//Characteristic length Ra_1=g*b*(Tp-T_surr)*(L^3)*Pr/(nu^2); disp(Ra_1,"(a) The Rayleigh no is") Nu_a=((0.825+(0.387*(Ra_1^(1/6)))/((1+((0.492/Pr)^(9/16)))^(8/27)))^2); disp(Nu_a,"The natural convection Nusselt number is") h_a=k*Nu_a/L;//[W/m^2.degree Celcius] As=L^2;//[m^2] Q_a=h_a*As*(Tp-T_surr);//[W] disp("W",ceil(Q_a),"Heat loss to the surrounding is") //Solution (b) Lc_b=As/(4*L);//[m] Ra_2=g*b*(Tp-T_surr)*(Lc_b^3)*Pr/(nu^2); disp(Ra_2,"(b) The Rayleigh number is") Nu_b=0.54*(Ra_2^(1/4)); disp(Nu_b,"The natural convection Nusselt number is") h_b=k*Nu_b/Lc_b;//[W/m^2.degree Celcius] Q_b=h_b*As*(Tp-T_surr);//[W] disp("W",round(Q_b),"Heat Loss is") //Solution (c) Lc_c=Lc_b Nu_c=(0.27*Ra_2^(1/4)); disp(Nu_c,"(c) Natural convection Nusselt number") h_c=k*Nu_c/Lc_c;//[W/m^2.degree Celcius] Q_c=h_c*As*(Tp-T_surr);//[W] disp("W",Q_c,"Heat Loss is") Q_rad=e*(5.67*10^(-8))*As*(((Tp+273)^4)-((T_surr+273)^4));//[W] disp("W",round(Q_rad),"Radiation heat loss is")