NBS TECHNICAL NOTE 1039 U.S. DEPARTMENT OF COMMERCE /National Bureau of Standards A Computer Program for the Prediction of Viscosity and Thermal Conductivity in Hydrocarbon Mixtures NATIONAL BUREAU OF STANDARDS The National Bureau of Standards' was established by an act of Congress on March 3, 1901. The Bureau's overall goal is to strengthen and advance the Nation's science and technology and facilitate their effective application for public benefit. To this end, the Bureau conducts research and provides: (1) a basis for the Nation's physical measurement system, (2) scientific and technological services for industry and government, (3) a technical basis for equity in trade, and (4) technical services to promote public safety. The Bureau's technical work is per- formed by the National Measurement Laboratory, the National Engineering Laboratory, and the Institute for Computer Sciences and Technology. THE NATIONAL MEASUREMENT LABORATORY provides the national system ol physical and chemical and materials measurement; coordinates the system with measurement systems of other nations and furnishes essential services leading to accurate and uniform physical and chemical measurement throughout the Nation's scientific community, industry, and commerce; conducts materials research leading to improved methods of measurement, standards, and data on the properties of materials needed by industry, commerce, educational institutions, and Government; provides advisory and research services to other Government agencies; develops, produces, and distributes Standard Reference Materials; and provides calibration services. The Laboratory consists of the following centers: Absolute Physical Quantities 2 — Radiation Research — Thermodynamics and Molecular Science — Analytical Chemistry — Materials Science. 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THE INSTITUTE FOR COMPUTER SCIENCES AND TECHNOLOGY conducts research and provides scientific and technical services to aid Federal agencies in the selection, acquisition, application, and use of computer technology to improve effectiveness and economy in Government operations in accordance with Public Law 89-306 (40 U.S.C. 759), relevant Executive Orders, and other directives; carries out this mission by managing the Federal Information Processing Standards Program, developing Federal ADP standards guidelines, and managing Federal participation in ADP voluntary standardization activities; provides scientific and technological advisory services and assistance to Federal agencies; and provides the technical foundation for computer-related policies of the Federal Government. The Institute consists of the following centers: Programming Science and Technology — Computer Systems Engineering. 'Headquarters and Laboratories at Gaithersburg, MD, unless otherwise noted; mailing address Washington, DC 20234. : Some divisions within the center are located at Boulder, CO 80303. A Computer Program for the Prediction of Viscosity and Thermal Conductivity in Hydrocarbon Mixtures .tAttoPAL. BURKAC Of ST ANDASM L1BBABY JUL 2 1981 not. i' u^, CiUoo James F. Ely no- ioz<\ H.J.M. Hanley int Thermophysical Properties Division National Engineering Laboratory National Bureau of Standards Boulder, Colorado 80303 ** OF ° Jrf. 7 U.S. DEPARTMENT OF COMMERCE, Malcolm Baldrige, Secretary NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Director Issued April 1981 NATIONAL BUREAU OF STANDARDS TECHNICAL NOTE 1039 Nat. Bur. Stand. (U.S.), Tech. Note 1039, 80 pages (April 1981) CODEN: NBTNAE U.S. GOVERNMENT PRINTING OFFICE WASHINGTON: 1981 For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402 Price $4.00 (Add 25 percent for other than U.S. mailing) CONTENTS Page 1. INTRODUCTION 1 2. THE ONE-FLUID MODEL AND EQUATIONS 2 2.1 Extended Corresponding States 4 2.2 Mixing Rules and Assumptions 5 3. SUMMARY OF THE CALCULATION PROCEDURE 7 4. THE REFERENCE FLUID: EXTENDED EQUATIONS FOR METHANE 7 5. RESULTS FOR PURE FLUIDS 14 6. RESULTS FOR MIXTURES 14 7. CONCLUSIONS 25 8. COMPUTER PROGRAM 25 9. ACKNOWLEDGMENTS 31 10. REFERENCES 32 APPENDIX A. TRAPP USER'S GUIDE 33 APPENDIX B. LISTING OF COMPUTER PROGRAM TRAPP 42 in LIST OF FIGURES Page Figure 1. (a) Comparison of reduced density of methane and n-decane as a function of reduced temperature, (b) Comparison of scaled viscosity of methane and n-decane as a function of reduced density 9 Figure 2. Comparison of calculated and experimental viscosity of methane, pentane, decane and hexadecane as a function of reduced density 20 Figure 3. Comparison of calculated and experimental viscosity for toluene, carbon dioxide, ethylene and isobutane 21 Figure 4. Comparison of calculated and experimental thermal conductivity for propane, decane, hexadecane, eicosane and methyl cyclohexane 22 Figure 5. Comparison of calculated and experimental thermal conductivity for ethylene, 1-hexene, benzene, toulene, p-xylene and carbon dioxide 23 Figure 6. Comparison of calculated and experimental viscosity of selected paraffin binary mixtures as a function of reduced density 28 Figure 7. Comparison of calculated and experimental viscosity of selected aromatic/paraffin mixtures 29 Figure 8. Comparison of calculated and experimental thermal conductivity of selected binary mixtures 30 Figure Al. Block diagram of computer program TRAPP 35 Figure A2. Flow diagram of I/O portion of TRAPP 38 LIST OF TABLES Table 1. Reference Fluid Equation of State 10 Table 2. Coefficients for Shape Factor Correlations 12 Table 3. Reference Fluid Viscosity Correlation 13 Table 4. Reference Fluid Translational Thermal Conductivity Correlation 15 Table 5. Summary of Calculated Results for Pure Fluid Viscosity . 16 Table 6. Summary of Calculated Results for Pure Fluid Thermal Conductivity 18 IV LIST OF TABLES (Continued) Page Table 7. Summary of Results for Binary Mixture Viscosity 26 Table 8. Summary of Results for Binary Mixture Thermal Conductivity . 27 Table Al. Listing of Components and TRAPP Data Base 34 Table A2 . Sample Input and Output 39 Table A3. Sample Input and Output 40 Table A4. Sample Input and Output 41 A COMPUTER PROGRAM FOR THE PREDICTION OF VISCOSITY AND THERMAL CONDUCTIVITY IN HYDROCARBON MIXTURES by James F. Ely and H. J. M. Hartley Thermophysical Properties Division National Engineering Laboratory National Bureau of Standards Boulder, Colorado 80303 A model for the prediction of the density, viscosity and thermal conductivity of non-polar fluid mixtures over the entire range of pVT states is presented. The model is based on the extended corresponding states model and covers molecular weight ranges including C20 Only pure component equilibrium data such as the critical constants are required as input to the calculation procedure — no transport data are required. Extensive comparisons with experimental data for pure fluids and binary mixtures are presented. The average percentage deviation for both the viscosity and thermal conductivity was observed to be less than 8 percent. A computer program (TRAPP) which performs the calculations reported in this manuscript is described and listed in the Appendices. Key words: Computer Droaram; density; extended corresDonding states; fluid mixtures; thermal conductivity; viscosity. 1. INTRODUCTION Engineering design requires transport properties for heat exchangers, compressors, pumps and for example, pipelines. Owing to the complexity of transport phenomena in general, accurate methods for the prediction of these properties have not advanced to a level comparable to equilibrium properties. In fact, most engineering calculations of transport properties are based on empirical correlations which are generally limited to narrow ranges of pressure and temperature and very frequently to pure fluids. These methods have been reviewed by Reid, et al . [1]. The purpose of this manuscript is to present a reliable, self-consistent method for predicting the density, viscosity and thermal conductivity of pure non-polar fluids and their mixtures. The method is applicable to a wide variety of chemical types, to thermodynamic states ranging from the dilute gas to compressed liquid and, in principle, the number of mixture components is unrestricted. The procedure is an extension of a method [2,3] which was proposed to estimate the transport properties of natural gas and similar mixtures and is based on the corresponding states principle and the conf ormal , one-fluid concept. It is predictive and requires only the critical parameters, Pitzer's acentric factor and the component ideal gas heat capacity as input. No mixture properties or transport data are required. The basic