From b1f5c3f8d6671b4331cef1dcebdf63b7a43a3a2b Mon Sep 17 00:00:00 2001 From: priyanka Date: Wed, 24 Jun 2015 15:03:17 +0530 Subject: initial commit / add all books --- 2510/CH19/EX19.7/Ex19_7.sce | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) create mode 100755 2510/CH19/EX19.7/Ex19_7.sce (limited to '2510/CH19/EX19.7') diff --git a/2510/CH19/EX19.7/Ex19_7.sce b/2510/CH19/EX19.7/Ex19_7.sce new file mode 100755 index 000000000..4cc7b8abd --- /dev/null +++ b/2510/CH19/EX19.7/Ex19_7.sce @@ -0,0 +1,27 @@ +//Variable declaration: +D2 = 0.5/10**3 //External diameter of needle (m) +h3 = 12 //Heat transfer coefficient (W/m^2.K) +L = 1 //Insulation thickness (m) +T1 = 95 //Reactant temperature ( C) +T3 = 20 //Ambient air temperature ( C) +k1 = 16 //Thermal conductivity of needle (W/m.K) +k3 = 0.0242 //Thermal conductivity of air (W/m.K) +D3 = 2/10**3 //Diameter of rubber tube (m) + +//Calculation: +r2 = D2/2 //External radius of needle (m) +r3 = D3/2 //Radius of rubber tube (m) +Rt1 = 1/(h3*(2*%pi*r2*L)) //Thermal resistance ( C/W) +Q1 = (T1-T3)/Rt1 //Rate of heat flow in the absence of insulation (W) +Bi = h3*D2/k1 //Biot number +Nu = h3*D2/k3 //Nusselt number +R2 = log(r3/r2) //Thermal resistance of needle ( C/W) +R3 = 1/(h3*(2*%pi*r3*L)) //Thermal resistance of rubber tube ( C/W) +Rt2 = R2+R3 //Total thermal resistance ( C/W) +Q2 = (T1-T3)/Rt2 //Rate of heat loss (W) + +//Result: +printf("1. The rate of the heat loss from the hypodermic needle with the rubber insulation is : %.2f W .",Q1) +printf(" The rate of the heat loss from the hypodermic needle without the rubber insulation is : %.2f W .",Q2) +printf("2. The Biot number is : %f",Bi) +printf(" The nusselt number is : %.3f ",Nu) -- cgit