1 files changed, 22 insertions, 0 deletions
diff --git a/534/CH3/EX3.5/3_5_Critical_Thickness.sce b/534/CH3/EX3.5/3_5_Critical_Thickness.sce
new file mode 100644
index 000000000..6010ca20d
--- /dev/null
+++ b/534/CH3/EX3.5/3_5_Critical_Thickness.sce
@@ -0,0 +1,22 @@
+clear;
+clc;
+printf('FUNDAMENTALS OF HEAT AND MASS TRANSFER \n Incropera / Dewitt / Bergman / Lavine \n EXAMPLE 3.5   Page 119 \n'); //Example 3.5
+// Critical Thickness
+
+k = .055;    //[W/m.K] From Table A.3, Cellular glass at Temp 285K
+h = 5;       //[W/m^2.K]
+ri = 5*10^-3;      //[m]  radius of tube
+
+rct = k/h;     // [m] Critical Thickness of Insulation for maximum Heat loss or minimum resistance
+
+x = linspace(0,.07,100);
+ycond=(2.30*log10((x+ri)/ri)/(2*%pi*k));
+yconv=(2*%pi*(x+ri)*h)^-1;
+ytot=yconv+ycond;
+clf();
+plot(x,ycond,x,yconv,x,ytot);
+xtitle("Resistance vs Radii", "r-ri (m)", "R (m.K/W)");
+legend ("Rcond", "Rconv", "Rtotal");
+
+printf("\n\n Critical Radius is = %.3f m \n Heat transfer will increase with the addition of insulation up to a thickness of %.3f m",rct,rct-ri);
+//END
+\ No newline at end of file