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clear;
clc;
printf('FUNDAMENTALS OF HEAT AND MASS TRANSFER \n Incropera / Dewitt / Bergman / Lavine \n EXAMPLE 4.1 Page 211 \n'); //Example 4.1
// Thermal resistance of wire coating associated with peripheral variations in coating thickness
d = .005; //[m] Diameter of wire
k = .35; //[W/m.K] Thermal Conductivity
h = 15; //[W/m^2.K] Total coeff with Convection n Radiation
rcr = k/h; // [m] critical insulation radius
tcr = rcr - d/2; // [m] critical insulation Thickness
Rtcond = 2.302*log10(rcr/(d/2))/(2*%pi*k); //[K/W] Thermal resistance
//Using Table 4.1 Case 7
z = .5*tcr;
D=2*rcr;
Rtcond2D = (acosh((D^2 + d^2 - 4*z^2)/(2*D*d)))/(2*%pi*k);
printf("\n\n The reduction in thermal resistance of the insulation is %.2f K/W ", Rtcond-Rtcond2D);
//END
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