// Display mode mode(0); // Display warning for floating point exception ieee(1); clc; disp("Principles of Heat Transfer, 7th Ed. Frank Kreith et. al Chapter - 9 Example # 9.15 ") //Temperature in degree K T = 800; //Diameter of sphere in m D = 0.4; //Partial pressure of nitrogen in atm PN2 = 1; //Partial pressure of H2O in atm PH2O = 0.4; //Partial pressure of CO2 in atm PCO2 = 0.6; //The mean beam length for a spherical mass of gas is obtained from Table 9.7 //Beam length in m L = (2/3)*D; //The emissivities are given in Figs. 9.46 and 9.47 //Emissivity of H2O epsilonH2O = 0.15; //Emissivity of CO2 epsilonCO2 = 0.125; //N2 does not radiate appreciably at 800 K, but since the total gas pressure //is 2 atm, we must correct the 1-atm values for epsilon. //From Figs. 9.48 and 9.49 the pressure correction factors are //Pressure correction factor for H2O CH2O = 1.62; //Pressure correction factor for CO2 CCO2 = 1.12; //From fig. 9.50 //Chnage in emissivity deltaEpsilon = 0.014; //Finally, the emissivity of the mixture can be obtained from Eq. (9.114): disp("Emissivity of the mixture is") //Emissivity of the mixture epsilonMix = CH2O*epsilonH2O+CCO2*epsilonCO2-deltaEpsilon