path: root/Principles_Of_Heat_Transfer_by_F_Kreith/2-Heat_Conduction.ipynb

{
"cells": [
 {
		   "cell_type": "markdown",
	   "metadata": {},
	   "source": [
       "# Chapter 2: Heat Conduction"
	   ]
	},
{
		   "cell_type": "markdown",
		   "metadata": {},
		   "source": [
			"## Example 2.10: Transient_Response_of_Thermocouple.sce"
		   ]
		  },
  {
"cell_type": "code",
	   "execution_count": null,
	   "metadata": {
	    "collapsed": true
	   },
	   "outputs": [],
"source": [
"\n",
"\n",
"// Display mode\n",
"mode(0);\n",
"\n",
"// Display warning for floating point exception\n",
"ieee(1);\n",
"\n",
"clc;\n",
"disp('Principles of Heat Transfer, 7th Ed. Frank Kreith et. al Chapter - 2 Example # 2.10 ')\n",
"\n",
"//Diameter of copper wire in m\n",
"D = 0.1/100;\n",
"//Initial temperature in degree C\n",
"To = 150;\n",
"//Final surrounding temperature in degree C of air and water\n",
"Tinfinity = 40;\n",
"\n",
"//From table 12, appendix 2, we get the following data values for copper\n",
"//Thermal conductivity in W/mK\n",
"k = 391;\n",
"//Specific heat in J/kgK\n",
"c = 383;\n",
"//Density in kg/m3\n",
"rho = 8930;\n",
"\n",
"//Surface area of wire per unit length in m\n",
"A = %pi*D;\n",
"//Volume of wire per unit length in m2\n",
"V = ((%pi*D)*D)/4;\n",
"\n",
"//Heat transfer coefficient in the case of water in W/m2K\n",
"h = 80;\n",
"//Biot number in water\n",
"bi = (h*D)/(4*k);\n",
"//The temperature response is given by Eq. (2.84)\n",
"\n",
"//For water Bi*Fo is 0.0936t\n",
"//For air Bi*Fo is 0.0117t\n",
"\n",
"for i = 1:130\n",
"  //Position of grid\n",
"  x(1,i) = i;\n",
"  // Temperature of water in degree C\n",
"  Twater(1,i) = Tinfinity+(To-Tinfinity)*exp(-0.0936*i);\n",
"  // Temperature of air in degree C\n",
"  Tair(1,i) = Tinfinity+(To-Tinfinity)*exp(-0.0117*i);\n",
"end;\n",
"//Plotting curve\n",
"plot(x,Twater,'--r')\n",
"set(gca(),'auto_clear','off')\n",
"//Plotting curve\n",
"plot(x,Tair)\n",
"//Labelling axis\n",
"xlabel('time')\n",
"ylabel('temperature')\n",
"disp('Temperature drop in water is more than that of air')"
   ]
   }
,
{
		   "cell_type": "markdown",
		   "metadata": {},
		   "source": [
			"## Example 2.11: Minimum_Depth_of_Water_Mains.sce"
		   ]
		  },
  {
"cell_type": "code",
	   "execution_count": null,
	   "metadata": {
	    "collapsed": true
	   },
	   "outputs": [],
"source": [
"\n",
"\n",
"// Display mode\n",
"mode(0);\n",
"\n",
"// Display warning for floating point exception\n",
"ieee(1);\n",
"\n",
"clc;\n",
"disp('Principles of Heat Transfer, 7th Ed. Frank Kreith et. al Chapter - 2 Example # 2.11 ')\n",
"\n",
"//Initial temperature of soil in degree C\n",
"Ti = 20;\n",
"//Surface temperature of soil\n",
"Ts = -15;\n",
"//Critical temperature (Freezing temperature) in degree C\n",
"Tc = 0;\n",
"//Time in days\n",
"t = 60;\n",
"//Density of soil in kg/m3\n",
"rho = 2050;\n",
"//Thermal conductivity of soil in W/mK\n",
"k = 0.52;\n",
"//Specific heat in J/kgK\n",
"c = 1840;\n",
"//Diffusivity in m2/sec\n",
"alpha = k/(rho*c);\n",
"\n",
"//Finding the value of following to proceed further\n",
"//Z value\n",
"z = (Tc-Ts)/(Ti-Ts);\n",
"\n",
"//From table 43, it corresponds to an error function value of 0.4,\n",
"//proceeding\n",
"\n",
"disp('Minimum depth at which one must place a water main below the surface to avoid freezing in m is')\n",
"//Minimum depth at which one must place a water main below the surface to avoid freezing in m\n",
"xm = (0.4*2)*((((alpha*t)*24)*3600)^0.5)"
   ]
   }
,
{
		   "cell_type": "markdown",
		   "metadata": {},
		   "source": [
			"## Example 2.12: Steel_Component_Fabrication_Process.sce"
		   ]
		  },
  {
"cell_type": "code",
	   "execution_count": null,
	   "metadata": {
	    "collapsed": true
	   },
	   "outputs": [],
"source": [
"\n",
"\n",
"// Display mode\n",
"mode(0);\n",
"\n",
"// Display warning for floating point exception\n",
"ieee(1);\n",
"\n",
"clc;\n",
"disp('Principles of Heat Transfer, 7th Ed. Frank Kreith et. al Chapter - 2 Example # 2.12 ')\n",
"\n",
"//Length of steel component in m\n",
"L = 2;\n",
"//Radius of steel component in m\n",
"ro = 0.1;\n",
"//Thermal conductivity of steel in W/mK\n",
"k = 40;\n",
"//Thermal diffusivity in m2/s\n",
"alpha = 0.00001;\n",
"//Initital temperature in degree C\n",
"Ti = 400;\n",
"//Surrounding temperature in degree C\n",
"Tinfinity = 50;\n",
"//Heat transfer coefficient in W/m2K\n",
"h = 200;\n",
"//time of immersion in mins\n",
"t = 20;\n",
"\n",
"//Since the cylinder has a length 10 times the diameter, we can neglect end\n",
"//effects.\n",
"\n",
"//Calculating biot number\n",
"bi = (h*ro)/k;\n",
"if bi>0.1 then\n",
"  //Calculating fourier number\n",
"  fo = ((alpha*t)*60)/(ro*ro);\n",
"  //The initial amount of internal energy stored in the cylinder per unit\n",
"  //length in Ws/m\n",
"  Q = ((((k*%pi)*ro)*ro)*(Ti-Tinfinity))/alpha;\n",
"\n",
"  //The dimensionless centerline temperature for 1/Bi= 2.0 and Fo= 1.2 from\n",
"  //Fig. 2.43(a)\n",
"  //Centreline temperature in degree C\n",
"  T = Tinfinity+0.35*(Ti-Tinfinity);\n",
"  disp('Centreline temperature in degree C is')\n",
"  T\n",
"  //The surface temperature at r/r0= 1.0 and t= 1200 s is obtained from Fig. 2.43(b) in terms of the centerline temperature\n",
"  //Surface temperature in degree C\n",
"  Tr = Tinfinity+0.8*(T-Tinfinity);\n",
"  disp('Surface temperature in degree C is')\n",
"  Tr\n",
"  //Then the amount of heat transferred from the steel rod to the water can be obtained from Fig. 2.43(c). Since Q(t)/Qi= 0.61,\n",
"  disp('The heat transferred to the water during the initial 20 min in Wh is')\n",
"  //The heat transferred to the water during the initial 20 min in Wh\n",
"  Q = ((0.61*L)*Q)/3600\n",
"end;"
   ]
   }
,
{
		   "cell_type": "markdown",
		   "metadata": {},
		   "source": [
			"## Example 2.13: Analysis_of_Concrete_Wall.sce"
		   ]
		  },
  {
"cell_type": "code",
	   "execution_count": null,
	   "metadata": {
	    "collapsed": true
	   },
	   "outputs": [],
"source": [
"\n",
"\n",
"// Display mode\n",
"mode(0);\n",
"\n",
"// Display warning for floating point exception\n",
"ieee(1);\n",
"\n",
"clc;\n",
"disp('Principles of Heat Transfer, 7th Ed. Frank Kreith et. al Chapter - 2 Example # 2.13 ')\n",
"\n",
"//Thickness of wall in m\n",
"L = 0.5;\n",
"//Initial temperature in degree C\n",
"Ti = 60;\n",
"//Combustion gas (Surrounding) temperature in degree C\n",
"Tinfinity = 900;\n",
"//Heat transfer coefficient in W/m2K\n",
"h = 25;\n",
"//Thermal conductivity in W/mk\n",
"k = 1.25;\n",
"//Specific heat in J/KgK\n",
"c = 837;\n",
"//Density in kg/m3\n",
"rho = 500;\n",
"//Thermal diffusivity in m2/s\n",
"alpha = 0.000003;\n",
"//Required temperature to achieve in degree C\n",
"Ts = 600;\n",
"\n",
"//Calculating temperature ratio\n",
"z = (Ts-Tinfinity)/(Ti-Tinfinity);\n",
"//Reciprocal biot number\n",
"bi = k/(h*L);\n",
"\n",
"\n",
"//From Fig. 2.42(a) we find that for the above conditions the Fourier number= 0.70 at the midplane.\n",
"//Time in hours\n",
"t = ((0.7*L)*L)/alpha;\n",
"disp('Time in hours is')\n",
"//Time in hours\n",
"t = t/3600\n",
"\n",
"//The temperature distribution in the wall 16 h after the transient was\n",
"//initiated can be obtained from Fig. 2.42(b) for various values of x/L\n",
"\n",
"disp('Temperature distribution in degree C is')\n",
"disp('  (x/l)  = 1.00 0.80 0.60 0.40 0.20')\n",
"disp('Fraction = 0.13 0.41 0.64 0.83 0.96')\n",
"\n",
"//The heat transferred to the wall per square meter of surface area during\n",
"//the transient can be obtained from Fig. 2.42(c).\n",
"disp('Heat transfer in J/m2 is')\n",
"//Heat transfer in J/m2\n",
"Q = ((c*rho)*L)*(Ti-Tinfinity)"
   ]
   }
,
{
		   "cell_type": "markdown",
		   "metadata": {},
		   "source": [
			"## Example 2.14: Cylinder_Places_in_Hot_Oven.sce"
		   ]
		  },
  {
"cell_type": "code",
	   "execution_count": null,
	   "metadata": {
	    "collapsed": true
	   },
	   "outputs": [],
"source": [
"\n",
"\n",
"// Display mode\n",
"mode(0);\n",
"\n",
"// Display warning for floating point exception\n",
"ieee(1);\n",
"\n",
"clc;\n",
"disp('Principles of Heat Transfer, 7th Ed. Frank Kreith et. al Chapter - 2 Example # 2.14 ')\n",
"\n",
"//Radius of cylinder in m\n",
"ro = 0.05;\n",
"//Length of cylinder in m\n",
"L = 0.16;\n",
"//Thermal conductivity in W/mK\n",
"k = 0.5;\n",
"//Thermal diffusivity in m2/s\n",
"alpha = 0.0000005;\n",
"//Initial temperature in degree C\n",
"Ti = 20;\n",
"//Surrounding temperature in degree C\n",
"Tinfinity = 500;\n",
"//Heat transfer coefficient in W/m2K\n",
"h = 30;\n",
"//Time in mins\n",
"t = 30;\n",
"\n",
"//Biot number\n",
"bi = (h*ro)/k;\n",
"//Fourier number\n",
"fo = ((alpha*t)*60)/((L*L)/4);\n",
"\n",
"//From fig. 2.42(a)\n",
"//Po\n",
"P0 = 0.9;\n",
"//From fig. 2.42(a) and (b)\n",
"//Pl\n",
"PL = 0.243;\n",
"//From fig. 2.43(a)\n",
"//Co\n",
"C0 = 0.47;\n",
"//From fig. 2.43(a) and (b)\n",
"//Cr\n",
"CR = 0.155;\n",
"disp('Minimum temperature in degree C')\n",
"//Minimum temperature in degree C\n",
"Tmin = Tinfinity+((Ti-Tinfinity)*P0)*C0"
   ]
   }
,
{
		   "cell_type": "markdown",
		   "metadata": {},
		   "source": [
			"## Example 2.1: Calculation_of_Heat_Transfer_Coeffcient.sce"
		   ]
		  },
  {
"cell_type": "code",
	   "execution_count": null,
	   "metadata": {
	    "collapsed": true
	   },
	   "outputs": [],
"source": [
"\n",
"\n",
"// Display mode\n",
"mode(0);\n",
"\n",
"// Display warning for floating point exception\n",
"ieee(1);\n",
"\n",
"clc;\n",
"disp('Principles of Heat Transfer, 7th Ed. Frank Kreith et. al Chapter - 2 Example # 2.1 ')\n",
"\n",
"//Heat generation rate in W/m3\n",
"qg = 1000000;\n",
"//Length along which heat will be dissipated in m (thickness)\n",
"L = 0.01;\n",
"//Thermal conductivity at the required temperature in W/mK\n",
"k = 64;\n",
"\n",
"//Temperature of surrounding oil in degree C\n",
"Tinfinity = 80;\n",
"//Temperature of heater in degree C to be maintained\n",
"T1 = 200;\n",
"\n",
"disp('heat transfer coefficient in W/m2K from a heat balance')\n",
"//Heat transfer coefficient in W/m2K\n",
"h = ((qg*L)/2)/(T1-Tinfinity)"
   ]
   }
,
{
		   "cell_type": "markdown",
		   "metadata": {},
		   "source": [
			"## Example 2.2: Insulated_vs_Uninsulated_Copper_Pipe.sce"
		   ]
		  },
  {
"cell_type": "code",
	   "execution_count": null,
	   "metadata": {
	    "collapsed": true
	   },
	   "outputs": [],
"source": [
"\n",
"\n",
"// Display mode\n",
"mode(0);\n",
"\n",
"// Display warning for floating point exception\n",
"ieee(1);\n",
"\n",
"clc;\n",
"disp('Principles of Heat Transfer, 7th Ed. Frank Kreith et. al Chapter - 2 Example # 2.2 ')\n",
"\n",
"disp('Case of Uninsualted pipe')\n",
"//Calculating resistance to heat flow at internal surface\n",
"\n",
"//Internal radius in m\n",
"ri = 0.05;\n",
"//Heat transfer coefficient at inner surface for steam condensing in W/m2K\n",
"hci = 10000;\n",
"//Resistance in mK/W\n",
"R1 = 1/(((2*%pi)*ri)*hci);\n",
"\n",
"//Calculating resistance to heat flow at external surface\n",
"\n",
"//External radius in m\n",
"ro = 0.06;\n",
"//Heat transfer coefficient at outer surface in W/m2K\n",
"hco = 15;\n",
"//Resistance in mK/W\n",
"R3 = 1/(((2*%pi)*ro)*hco);\n",
"\n",
"//Calcualting resistance to heat flow due to pipe\n",
"\n",
"//Thermal conductivity of pipe in W/mK\n",
"kpipe = 400;\n",
"//Resistance in mK/W\n",
"R2 = log(ro/ri)/((2*%pi)*kpipe);\n",
"\n",
"//Temperatures of steam(pipe) and surrounding(air) in degree C\n",
"Ts = 110;\n",
"Tinfinity = 30;\n",
"\n",
"disp('Heat loss from uninsulated pipe in W/m is therefore')\n",
"//Heat loss from uninsulated pipe in W/m \n",
"q = (Ts-Tinfinity)/(R1+R2+R3)\n",
"\n",
"\n",
"disp('Case of insulated pipe')\n",
"//Calculating additional resistance between outer radius and new outer\n",
"//radius\n",
"\n",
"//Thermal conductivity of insulation in W/mK\n",
"k = 0.2;\n",
"//New outer radius in m\n",
"r3 = 0.11;\n",
"//Resistance in mK/W\n",
"R4 = log(r3/ro)/((2*%pi)*k);\n",
"\n",
"//Calculating new outer resistance\n",
"R0 = 1/(((2*%pi)*r3)*hco);\n",
"\n",
"\n",
"disp('Heat loss from insulated pipe in W/m is therefore')\n",
"//Heat loss from insulated pipe in W/m\n",
"q = (Ts-Tinfinity)/(R1+R2+R4+R0)"
   ]
   }
,
{
		   "cell_type": "markdown",
		   "metadata": {},
		   "source": [
			"## Example 2.3: Hot_Fluid_Flowing_Through_Pipe.sce"
		   ]
		  },
  {
"cell_type": "code",
	   "execution_count": null,
	   "metadata": {
	    "collapsed": true
	   },
	   "outputs": [],
"source": [
"\n",
"\n",
"// Display mode\n",
"mode(0);\n",
"\n",
"// Display warning for floating point exception\n",
"ieee(1);\n",
"\n",
"clc;\n",
"disp('Principles of Heat Transfer, 7th Ed. Frank Kreith et. al Chapter - 2 Example # 2.3 ')\n",
"\n",
"//Outer radius in m\n",
"ro = 0.02;\n",
"//Inner radius in m\n",
"ri = 0.015;\n",
"//Thermal conductivity of plastic in W/mK\n",
"k = 0.5;\n",
"//Internal convection heat transfer coefficient in W/m2K\n",
"hc1 = 300;\n",
"//Temperature of fluid in pipe in degree C\n",
"Thot = 200;\n",
"//Temperature of outside in degree C\n",
"Tcold = 30;\n",
"//External convection heat transfer coefficient in W/m2K\n",
"hc0 = 10;\n",
"\n",
"disp('Overall heat transfer coefficient in W/m2K is')\n",
"//Overall heat transfer coefficient in W/m2K\n",
"U0 = 1/(ro/(ri*hc1)+(ro*log(ro/ri))/k+1/hc0)\n",
"\n",
"disp('The heat loss per unit length in W/m is')\n",
"//The heat loss per unit length in W/m\n",
"q = (((U0*2)*%pi)*ro)*(Thot-Tcold)"
   ]
   }
,
{
		   "cell_type": "markdown",
		   "metadata": {},
		   "source": [
			"## Example 2.4: Boiling_Off_Of_Nitrogen.sce"
		   ]
		  },
  {
"cell_type": "code",
	   "execution_count": null,
	   "metadata": {
	    "collapsed": true
	   },
	   "outputs": [],
"source": [
"\n",
"\n",
"// Display mode\n",
"mode(0);\n",
"\n",
"// Display warning for floating point exception\n",
"ieee(1);\n",
"\n",
"clc;\n",
"disp('Principles of Heat Transfer, 7th Ed. Frank Kreith et. al Chapter - 2 Example # 2.4 ')\n",
"\n",
"//Temperature of liquid nitrogen in degree K\n",
"Tnitrogen = 77;\n",
"//Radius of container in m\n",
"ri = 0.25;\n",
"//Temperature of surrounding air in degree K\n",
"Tinfinity = 300;\n",
"//Thermal conductivity of insulating silica powder in W/mK\n",
"k = 0.0017;\n",
"//Outer radius of container with insulation in m\n",
"ro = 0.275;\n",
"//Latent heat of vaporization of liquid nitrogen in J/kg\n",
"hgf = 200000;\n",
"//convection coefficient at outer surface in W/m2K\n",
"hco = 20;\n",
"\n",
"//Calcaulting heat transfer to nitrogen\n",
"q = (Tinfinity-Tnitrogen)/(1/((((4*%pi)*ro)*ro)*hco)+(ro-ri)/((((4*%pi)*k)*ro)*ri));\n",
"\n",
"disp(' rate of liquid boil-off of nitrogen per hour is')\n",
"//rate of liquid boil-off of nitrogen per hour\n",
"m = (3600*q)/hgf"
   ]
   }
,
{
		   "cell_type": "markdown",
		   "metadata": {},
		   "source": [
			"## Example 2.5: Analysis_of_Nuclear_Reactor.sce"
		   ]
		  },
  {
"cell_type": "code",
	   "execution_count": null,
	   "metadata": {
	    "collapsed": true
	   },
	   "outputs": [],
"source": [
"\n",
"\n",
"// Display mode\n",
"mode(0);\n",
"\n",
"// Display warning for floating point exception\n",
"ieee(1);\n",
"\n",
"clc;\n",
"disp('Principles of Heat Transfer, 7th Ed. Frank Kreith et. al Chapter - 2 Example # 2.5 ')\n",
"\n",
"//Heat generation rate in W/m3\n",
"qg = 75000000;\n",
"//Outer radius of rods in m\n",
"ro = 0.025;\n",
"//Temperature of water in degree C\n",
"Twater = 120;\n",
"//Thermal cinductivity in W/mk\n",
"k = 29.5\n",
"//Heat transfer coefficient in W/m2K\n",
"hco = 55000;\n",
"\n",
"//Since rate of flow through the surface of the rod equals the rate of internal heat generation\n",
"//and\n",
"//The rate of heat flow by conduction at the outer surface equals the rate\n",
"//of heat flow by convection from the surface to the water\n",
"\n",
"//Surface Temperature in degree C\n",
"T0 = (qg*ro)/(2*hco)+Twater;\n",
"\n",
"disp('Maximum temperature in degree C')\n",
"//Maximum temperature in degree C\n",
"Tmax = T0+((qg*ro)*ro)/(4*k)"
   ]
   }
,
{
		   "cell_type": "markdown",
		   "metadata": {},
		   "source": [
			"## Example 2.6: Analysis_of_Copper_Pin_Fin.sce"
		   ]
		  },
  {
"cell_type": "code",
	   "execution_count": null,
	   "metadata": {
	    "collapsed": true
	   },
	   "outputs": [],
"source": [
"\n",
"\n",
"// Display mode\n",
"mode(0);\n",
"\n",
"// Display warning for floating point exception\n",
"ieee(1);\n",
"\n",
"clc;\n",
"disp('Principles of Heat Transfer, 7th Ed. Frank Kreith et. al Chapter - 2 Example # 2.6 ')\n",
"\n",
"//diameter of fin in m\n",
"d = 0.0025;\n",
"//Perimeter in m\n",
"P = %pi*d;\n",
"//Area in m2\n",
"A = ((%pi*d)*d)/4;\n",
"//Surface temperature in degree C\n",
"Ts = 95;\n",
"//Ambient temperature in degree c\n",
"Tinfinity = 25;\n",
"//Heat transfer coefficient in W/m2K\n",
"hc = 10;\n",
"//From table 12, value of thermal conductivity in W/mK\n",
"k = 396;\n",
"\n",
"disp('Case of an infinitely long fin')\n",
"disp('Heat loss for the “infintely long” fin in W is')\n",
"//Heat loss for the “infintely long” fin in W\n",
"qfin = ((((hc*P)*k)*A)^0.5)*(Ts-Tinfinity)\n",
"\n",
"disp('Case 2: Fin length of 2.5cm')\n",
"//Length in cm\n",
"L = 2.5/100;\n",
"//Parameter m\n",
"m = ((hc*P)/(k*A))^0.5;\n",
"disp('Heat loss in this case in W is')\n",
"//Heat loss in this case in W\n",
"qfin = qfin*((sinh(m*L)+(hc/(m*k))*cosh(m*L))/(cosh(m*L)+(hc/(m*k))*sinh(m*L)))\n",
"\n",
"disp('For the two solutions to be within 5%')\n",
"//((sinh(m*L)+(hc/(m*k))*cosh(m*L))/(cosh(m*L)+(hc/(m*k))*sinh(m*L))) must\n",
"//be less than 0.95\n",
"disp('L must be greater than 28.3cm')"
   ]
   }
,
{
		   "cell_type": "markdown",
		   "metadata": {},
		   "source": [
			"## Example 2.7: Heat_Loss_From_Circumferential_Fin.sce"
		   ]
		  },
  {
"cell_type": "code",
	   "execution_count": null,
	   "metadata": {
	    "collapsed": true
	   },
	   "outputs": [],
"source": [
"\n",
"\n",
"// Display mode\n",
"mode(0);\n",
"\n",
"// Display warning for floating point exception\n",
"ieee(1);\n",
"\n",
"clc;\n",
"disp('Principles of Heat Transfer, 7th Ed. Frank Kreith et. al Chapter - 2 Example # 2.7 ')\n",
"\n",
"//Thermal conductivity of alumunium in W/mK\n",
"k = 200;\n",
"//Outer radius of system in m\n",
"ro = 5.5/200;\n",
"//Inner radius of system in m\n",
"ri = 2.5/200;\n",
"//Thickness of fin in m\n",
"t = 0.1/100;\n",
"\n",
"//Temperature of pipe in  degree C\n",
"Ts = 100;\n",
"//Temperature of surrounding in degree C\n",
"Tinfinity = 25;\n",
"//Heat transfer coefficient in W/m2K\n",
"h = 65;\n",
"\n",
"//calculating fin efficiency\n",
"//From Fig. 2.22 on page 103, the fin efficiency is found to be 91%.\n",
"\n",
"//Area of fin\n",
"A = (2*%pi)*((ro+t/2)^2-ri*ri);\n",
"\n",
"disp('The rate of heat loss from a single fin in W is')\n",
"//The rate of heat loss from a single fin in W\n",
"q = ((0.91*h)*A)*(Ts-Tinfinity)"
   ]
   }
,
{
		   "cell_type": "markdown",
		   "metadata": {},
		   "source": [
			"## Example 2.8: Heat_Loss_From_Buried_Pipe.sce"
		   ]
		  },
  {
"cell_type": "code",
	   "execution_count": null,
	   "metadata": {
	    "collapsed": true
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"\n",
"\n",
"// Display mode\n",
"mode(0);\n",
"\n",
"// Display warning for floating point exception\n",
"ieee(1);\n",
"\n",
"clc;\n",
"disp('Principles of Heat Transfer, 7th Ed. Frank Kreith et. al Chapter - 2 Example # 2.8 ')\n",
"\n",
"//Diameter of pipe in m\n",
"D = 0.1;\n",
"//Depth under which it is sunk in m\n",
"z = 0.6;\n",
"//Temperature of pipe in degree C\n",
"Tpipe = 100;\n",
"//Temperature of soil in degree C\n",
"Tsoil = 20;\n",
"//Thermal conductivity in W/mK\n",
"k = 0.4;\n",
"\n",
"\n",
"//From table 2.2 on page 112, calculating shape factor\n",
"//Shape factor\n",
"S = (2*%pi)/acosh((2*z)/D);\n",
"disp(' rate of heat loss per meter length in W/m is')\n",
"//rate of heat loss per meter length in W/m\n",
"q = (k*S)*(Tpipe-Tsoil)"
   ]
   }
,
{
		   "cell_type": "markdown",
		   "metadata": {},
		   "source": [
			"## Example 2.9: Heat_Loss_From_Cubic_Furnace.sce"
		   ]
		  },
  {
"cell_type": "code",
	   "execution_count": null,
	   "metadata": {
	    "collapsed": true
	   },
	   "outputs": [],
"source": [
"\n",
"\n",
"// Display mode\n",
"mode(0);\n",
"\n",
"// Display warning for floating point exception\n",
"ieee(1);\n",
"\n",
"clc;\n",
"disp('Principles of Heat Transfer, 7th Ed. Frank Kreith et. al Chapter - 2 Example # 2.9 ')\n",
"\n",
"//Thermal conductivity in W/mC\n",
"k = 1.04;\n",
"//For square length and breadth are equal and are in m\n",
"D = 0.5;\n",
"//Area in m2\n",
"A = D*D;\n",
"//Thickness in m\n",
"L = 0.1;\n",
"//Inside temperature in degree C\n",
"Ti = 500;\n",
"\n",
"//Outside temperature in degree C\n",
"To = 50;\n",
"//Shape factor for walls\n",
"Sw = A/L;\n",
"//Shape factor for corners\n",
"Sc = 0.15*L;\n",
"//Shape factor for edges\n",
"Se = 0.54*D;\n",
"\n",
"//There are 6 wall sections, 12 edges, and 8 corners, so that the total\n",
"//shape factor is\n",
"S = 6*Sw+12*Se+8*Sc;\n",
"\n",
"disp('Heat flow in W is')\n",
"//Heat flow in W \n",
"q = (k*S)*(Ti-To)"
   ]
   }
],
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