From 7f60ea012dd2524dae921a2a35adbf7ef21f2bb6 Mon Sep 17 00:00:00 2001 From: prashantsinalkar Date: Tue, 10 Oct 2017 12:27:19 +0530 Subject: initial commit / add all books --- 534/CH3/EX3.5/3_5_Critical_Thickness.sce | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) create mode 100644 534/CH3/EX3.5/3_5_Critical_Thickness.sce (limited to '534/CH3/EX3.5/3_5_Critical_Thickness.sce') 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 -- cgit