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clc;
clear;
//Example 3.37
k=0.03 //W/(m.K)
Npr=0.697 //Prandtl number
v=2.076*10^-6 //m^2/s
Beta=0.002915 //K^-1
D=25 ; //[Diameter in cm]
D=D/100 //[m]
Tf=343 //Film temperature in [K]
A=%pi*(D/2)^2 //Area in [m^2]
P=%pi*D //Perimeter [m]
T1=293 //[K]
T2=393 //[K]
g=9.81 //[m/s^2]
//Case (i) HOT SURFACE FACING UPWARD
L=A/P //Characteristic length in [m]
Beta=1/Tf; //[K^-1]
dT=T2-T1 //[K]
Ngr=(g*Beta*dT*(L^3))/(v^2) //Grashoff number
Nra=Ngr*Npr
Nnu=0.15*(Nra^(1.0/3.0)) //Nusselt number
h=Nnu*k/L //[W/m^2.K]
Q=h*A*dT //[W]
printf("\nHeat transferred when disc is horizontal with hot surface facing upward is %f W\n",Q);
//Case-(ii) HOT FACE FACING DOWNWARD
Nnu=0.27*(Nra^(1/4)) //Nusselt number
h=Nnu*k/L //W/(m^2.K)
Q=h*A*dT //[W]
printf("\nHeat transferred when disc is horizontal with hot surface facing downward is %f W\n",Q);
//Case-(iii)-For disc vertical
L=0.25 //Characteristic length[m]
D=L //dia[m]
A=%pi*((D/2)^2) //[sq m]
Ngr=(g*Beta*dT*(L^3))/(v^2) //Grashoff number
Npr=0.697
Nra=Ngr*Npr
Nnu=0.10*(Nra^(1/3)) //Nusselt number
h=Nnu*k/D //[W/(m^2.K)]
Q=h*A*dT //[W]
printf("For vertical disc,heat transferred is %f W",Q);
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