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clear;
clc;
printf('FUNDAMENTALS OF HEAT AND MASS TRANSFER \n Incropera / Dewitt / Bergman / Lavine \n EXAMPLE 9.4 Page 580 \n'); //Example 9.4
// Heat Loss from pipe per meter of length
//Operating Conditions
Ts = 165+273; //[K] Surface Temperature
Tsurr = 23+273; //[K] Surrounding Temperature
D = .1 ;//[m] Diameter
e = .85 ;// emissivity
stfncnstt=5.67*10^(-8) ;// [W/m^2.K^4] - Stefan Boltzmann Constant
//Table A.4 Air Properties T = 303 K
k = 31.3*10^-3 ;//[W/m.K] Conductivity
uv = 22.8*10^-6 ;//[m^2/s] Kinematic Viscosity
al = 32.8*10^-6 ;//[m^2/s] alpha
be = 2.725*10^-3 ;//[K^-1] Tf^-1
Pr = .697 ;// Prandtl number
g = 9.81 ;//[m^2/s] gravitational constt
Ra = g*be*(Ts-Tsurr)/al*D^3/uv;
//From equatiom 9.34
Nu = [.60 + .387*Ra^(1/6)/[1+(.559/Pr)^(9/16)]^(8/27)]^2;
h = Nu*k/D;
qconv = h*%pi*D*(Ts-Tsurr);
qrad = e*%pi*D*stfncnstt*(Ts^4-Tsurr^4);
printf("\n Rate of heat loss per unit length of pipe is %i W/m",qconv+qrad);
//END
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