{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "# Chapter 4: Radiation" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 4.1: Radiation_between_large_2_planes.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "clc\n", "//page 75\n", "printf('\t example 4.1 \n');\n", "printf('\t approximate values are mentioned in the book \n');\n", "T1=1000+460; // R\n", "T2=800+460; // R\n", "Q=((0.173)*((14.6)^4-(12.6)^4)); // using eq.4.24,Btu/(hr)*(ft^2)\n", "printf('\t heat removed from colder wall per unit area is : %.0f Btu/(hr)*(ft^2) \n',Q);\n", "// end" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 4.2: Radiation_between_Planes_with_Different_Emissivities.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "printf('\t example 4.2 \n');\n", "printf('\t approximate values are mentioned in the book \n');\n", "T1=1000+460; // R\n", "T2=800+460; // R\n", "e1=0.6; // emissivity of hotter wall\n", "e2=0.8; // emissivity of colder wall\n", "Q=(((0.173)/((1/0.6)+(1/0.8)-1))*((14.6)^4-(12.6)^4)); // using eq.4.26,heat loss per unit area,Btu/(hr)*(ft^2)\n", "printf('\t heat removed from colder wall per unit area is : %.0f Btu/(hr)*(ft^2) \n',Q);\n", "printf('\t For perfect black bodies the value was 3500 Btu/(hr)(ft^2) \n');\n", "// end" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 4.3: Calculation_of_Radiation_from_a_Pipe.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "clc\n", "//page 78\n", "printf('\t example 4.3 \n');\n", "printf('\t approximate values are mentioned in the book \n');\n", "T1=125+460; // R\n", "T2=70+460; // R\n", "e=0.9; // emissivity,using table 4.1B\n", "A=(%pi)*(3.375/12)*(1); // area,ft^2/lin ft\n", "printf('\t area is : %.2f ft^2/lin ft \n',A);\n", "Q=(0.9)*(0.88)*(0.173)*((T1/100)^4-(T2/100)^4); // heat loss using eq.4.32,Btu/(hr)*(lin ft)\n", "printf('\t heat loss is : %.1f Btu/(hr)*(lin ft) \n',Q);\n", "hr=(Q)/((A)*(T1-T2)); // fictitious film coefficient,using eq 4.33,Btu/(hr)(ft^2)(F)\n", "printf('\t fictitious film coefficient is : %.2f Btu/(hr)(ft^2)(F) \n',hr);\n", "//end" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 4.4: Radiation_from_a_Pipe_to_a_Duct.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "clc\n", "//page 82\n", "printf('\t example 4.4 \n');\n", "printf('\t approximate values are mentioned in the book \n');\n", "T1=300+460; // R\n", "T2=75+460; //R\n", "A1=0.622; // area from table 11 in the appendix A,ft^2/lin ft\n", "A2=4*(1*1); // surface area of duct,ft^2/lin ft\n", "e1=0.79; // emissivity of oxidized steel from table 4.1\n", "e2=0.276; // emissivity of oxidized zinc from table 4.1\n", "printf('\t surface area of pipe is : %.3f ft^2/lin ft \n',A1);\n", "printf('\t surface area of duct is : %.0f ft^2/lin ft \n',A2);\n", "printf('\t The surface of the pipe is not negligible by comparison with that of the duct, and(f) of Table 4.2 applies most nearly \n');\n", "Fa=1; // from table 4.2\n", "Fe=((1)/((1/e1)+((A1/A2)*((1/e2)-1)))); // from table 4.2\n", "printf('\t Fe is : %.2f \n',Fe);\n", "Q=(0.173*10^-8)*(Fa)*(Fe)*(A1)*((T1)^4-(T2)^4); // heat loss due to radiation,Btu/(hr)*(lin ft)\n", "printf('\t heat loss due to radiation is : %.0f Btu/(hr)*(lin ft) \n',Q);\n", "// end" ] } ], "metadata": { "kernelspec": { "display_name": "Scilab", "language": "scilab", "name": "scilab" }, "language_info": { "file_extension": ".sce", "help_links": [ { "text": "MetaKernel Magics", "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md" } ], "mimetype": "text/x-octave", "name": "scilab", "version": "0.7.1" } }, "nbformat": 4, "nbformat_minor": 0 }