This content is not included in your SAE MOBILUS subscription, or you are not logged in.
The Direct Transition of Fuel Sprays to theDense-Fluid Mixing Regime in the Contextof Modern Compression Ignition Engines
ISSN: 0148-7191, e-ISSN: 2688-3627
Published April 03, 2018 by SAE International in United States
This content contains downloadable datasetsAnnotation ability available
Fuel supercriticality has recently received significant attention due to the elevated pressures and temperatures that directly-injected (DI) fuel sprays encounter in modern internal combustion (IC) engines. This paper presents a theoretical examination of conventional and alternative DI fuels at conditions relevant to the operation of compression ignition (CI) engines. The focus is to identify the conditions under which the injected liquid fuel can bypass the atomization process and directly transition to a diffusional mixing regime with the chamber gas. Evaluating the microscopic length-scales of the phase boundary associated with the injection of liquid nitrogen into its own vapor, it is found that the conventional threshold based on the interfacial Knudsen number (i.e. Kn = 0.1) does not adequately quantify the direct transition between sub- and supercriticality. Instead, a threshold that is an order of magnitude smaller is more appropriate for this purpose. Extending the analysis to a range of diesel fuel surrogates (e.g. n-heptane and n-dodecane), and alternative engine fuels that can be blended for use in CI engines (e.g. dimethyl ether and propane), it is then found that the local Knudsen numbers associated with the injection of conventional liquid fuels are significantly higher than those previously calculated in the literature, suggesting that those fuels will not directly transition to a dense-fluid mixing regime for all engine relevant conditions. However, the results show that the immediate transition to a single-phase regime may be relevant to lighter alternative fuels like DME and propane, which is attributed to the significantly lower critical temperature of these fuels, as well as their higher miscibility with the gas in the chamber.
CitationPoursadegh, F., Lacey, J., Brear, M., and Gordon, R., "The Direct Transition of Fuel Sprays to theDense-Fluid Mixing Regime in the Contextof Modern Compression Ignition Engines," SAE Technical Paper 2018-01-0298, 2018, https://doi.org/10.4271/2018-01-0298.
Data Sets - Support Documents
|[Unnamed Dataset 1]|
- Chehroudi, B., Talley, D., and Coy, E., “Visual Characteristics and Initial Growth Rates of Round Cryogenic Jets at Subcritical and Supercritical Pressures,” Physics of Fluids 14(2):850-861, 2002.
- Mayer, W., Schik, A., Vielle, B., Chauveau, C. et al., “Atomization and Breakup of Cryogenic Propellants under High-Pressure Subcritical and Supercritical Conditions,” Journal of Propulsion and Power 14(5):835-842, 1998.
- Muthukumaran, C. and Vaidyanathan, A., “Experimental Study of Elliptical Jet from Supercritical to Subcritical Conditions Using Planar Laser Induced Fluorescence,” Physics of Fluids 27(3):034109, 2015.
- Roy, A., Joly, C., and Segal, C., “Disintegrating Supercritical Jets in a Subcritical Environment,” Journal of Fluid Mechanics 717:193-202, 2013.
- Bellan, J., “Supercritical (and Subcritical) Fluid Behavior and Modeling: Drops, Streams, Shear and Mixing Layers, Jets and Sprays,” Progress in Energy and Combustion Science 26:329-366, 2000.
- Zong, N. and Yang, V., “Cryogenic Fluid Jets and Mixing Layers in Transcritical and Supercritical Environments,” Combustion Science and Technology 178(1-3):193-227, 2006.
- Van Konynenburg, P. and Scott, R., “Critical Lines and Phase Equilibria in Binary Van Der Waals Mixtures,” Philosophical Transactions of the Royal Society of London A: Mathematical, Physical and Engineering Sciences 298(1442):495-540, 1980.
- Dahms, R.N., Manin, J., Pickett, L.M., and Oefelein, J.C., “Understanding High-Pressure Gas-Liquid Interface Phenomena in Diesel Engines,” Proceedings of the Combustion Institute 34(1):1667-1675, 2013.
- Dahms, R.N. and Oefelein, J.C., “On the Transition between two-Phase and Single-Phase Interface Dynamics in Multicomponent Fluids at Supercritical Pressures,” Physics of Fluids 25(9):092103, 2013.
- Dahms, R.N. and Oefelein, J.C., “Liquid Jet Breakup Regimes at Supercritical Pressures,” Combustion and Flame 162(10):3648-3657, 2015.
- Dahms, R.N. and Oefelein, J.C., “Non-equilibrium Gas-Liquid Interface Dynamics in High-Pressure Liquid Injection Systems,” Proceedings of the Combustion Institute 35(2):1587-1594, 2015.
- Oefelein, J., Lacaze, G., Dahms, R., Ruiz, A., and Misdariis, A., “Effects of Real-Fluid Thermodynamics on High-Pressure Fuel Injection Processes,” SAE Int. J. Engines 7(3):1125-1136, 2014.
- Lacaze, G., Misdariis, A., Ruiz, A., and Oefelein, J.C., “Analysis of High-Pressure Diesel Fuel Injection Processes Using LES with Real-Fluid Thermodynamics and Transport,” Proceedings of the Combustion Institute 35(2):1603-1611, 2015.
- Mo, G. and Qiao, L., “A Molecular Dynamics Investigation of N-Alkanes Vaporizing into Nitrogen: Transition from Subcritical to Supercritical,” Combustion and Flame 176:60-71, 2017.
- Qiu, L. and Reitz, R.D., “An Investigation of Thermodynamic States during High-Pressure Fuel Injection Using Equilibrium Thermodynamics,” Internation Journal of Multiphase Flow 72:24-38, 2015.
- Bork, B., Preusche, A., Weckenmann, F., Lamanna, G., and Dreizler, A., “Measurement of Species Concentration and Estimation of Temperature in the Wake of Evaporating N-Heptane Droplets at Trans-Critical Conditions,” Proceedings of the Combustion Institute 36(2):2433-2440, 2017.
- Abraham, J. and Givler, S., “Conditions in Which Vaporizing Fuel Drops Reach a Critical State in a Diesel Engine,” SAE Technical Paper 1999-01-0511, 1999, doi:10.4271/1999-01-0511.
- Zhu, G.-S. and Aggarwal, S.K., “Transient Supercritical Droplet Evaporation with Emphasis on the Effects of Equation of State,” International Journal of Heat and Mass Transfer 43(7):1157-1171, 2000.
- Zhu, G.-S. and Reitz, R.D., “A Model for High-Pressure Vaporization of Droplets of Complex Liquid Mixtures Using Continuous Thermodynamics,” International Journal of Heat and Mass Transfer 45(3):495-507, 2002.
- Manin, J., Bardi, M., Pickett, L., Dahms, R. et al., “Microscopic Investigation of the Atomization and Mixing Processes of Diesel Sprays Injected into High Pressure and Temperature Environments,” Fuel 134:531-543, 2014.
- Falgout, Z., Rahm, M., Wang, Z., and Linne, M., “Evidence for Supercritical Mixing Layers in the ECN Spray a,” Proceedings of the Combustion Institute 35(2):1579-1586, 2015.
- Crua, C., Manin, J., and Pickett, L.M., “Transition from Droplet Evaporation to Miscible Mixing at Diesel Engine Condition,” Proceedings of The 13th Triennial International Conference on Liquid Atomization and Spray Systems.
- Falgout, Z., Rahm, M., Sedarsky, D., and Linne, M., “Gas/Fuel Jet Interfaces under High Pressures and Temperatures,” Fuel 168:14-21, 2016.
- Wensing, M., Vogel, T., and Götz, G., “Transition of Diesel Spray to a Supercritical State under Engine Conditions,” International Journal of Engine Research 17(1):108-119, 2015.
- Poursadegh, F., Lacey, J.S., Brear, M.J., and Gordon, R.L., “On the Fuel Spray Transition to Dense Fluid Mixing at Reciprocating Engine Conditions,” Energy & Fuels 31(6):6445-6454, 2017.
- Lee, S., Oh, S., Choi, Y., and Kang, K., “Performance and Emission Characteristics of a CI Engine Operated with N-Butane Blended DME Fuel,” Applied Thermal Engineering 31(11):1929-1935, 2011.
- Kajitani, S., Chen, C.L., Oguma, M., Alam, M. et al., “Direct Injection Diesel Engine Operated with Propane - DME Blended Fuel,” SAE Technical Paper 982536, 1998, doi:10.4271/982536.
- Fujimoto, K., Ohno, Y., Goto, S., Kajitani, S. et al. , “DME Handbook,” Proc. Tokyo: Japan DME Forum.
- Kunz, O., Klimeck, R., Wagner, W., and Jaeschke, M., “The GERG-2004 Wide-Range Equation of State for Natural Gases and Other Mixtures,” (VDI Verlag, 2007).
- Lemmon, E. and Jacobsen, R., “A Generalized Model for the Thermodynamic Properties of Mixtures,” International Journal of Thermophysics 20(3):825-835, 1999.
- Lemmon, E.W., Huber, M.L., and McLinden, M.O., “NIST Standard Reference Database 23: Reference Fluid Thermodynamic and Transport Properties-REFPROP, Version 9.1, National Institute of Standards and Technology,” (Gaithersburg, Standard Reference Data Program, 2013).
- Sadus, R.J., “Calculating Critical Transitions of Fluid Mixtures: Theory Vs. Experiment,” AICHE Journal 40(8):1376-1403, 1994.
- Michelsen, M.L., “Calculation of Critical Points and Phase Boundaries in the Critical Region,” Fluid Phase Equilibria 16(1):57-76, 1984.
- Hirschfelder, J.O., Curtiss, C.F., Bird, R.B., and Mayer, M.G., “Molecular Theory of Gases and Liquids,” (New York, Wiley, 1954).
- Cahn, J.W. and Hilliard, J.E., “Free Energy of a Nonuniform System. I : Interfacial Free Energy,” Journal of Chemical Physics 28(2):258-267, 1958.
- Zuo, Y.-X. and Stenby, E.H., “A Linear Gradient Theory Model for Calculating Interfacial Tensions of Mixtures,” Journal of Colloid Interface Science 182(1):126-132, 1996.
- Lekner, J. and Henderson, J., “Theoretical Determination of the Thickness of a Liquid-Vapour Interface,” Physica A 94(3):545-558, 1978.
- Chapman, S. and Cowling, T.G., “The Mathematical Theory of Non-uniform Gases: An Account of the Kinetic Theory of Viscosity, Thermal Conduction and Diffusion in Gases,” (Cambridge, Cambridge University Press, 1970).
- Bird, G.A., “Molecular Gas Dynamics and the Direct Simulation of Gas Flows,” (Oxford, Clarendon Press, 1994).
- Koura, K. and Matsumoto, H., “Variable Soft Sphere Molecular Model for Inverse-Power-Law or Lennard-Jones Potential,” Physics of Fluids A: Fluid Dynamics 3(10):2459-2465, 1991.
- Webster, C.E., Drago, R.S., and Zerner, M.C., “Molecular Dimensions for Adsorptives,” Journal of the American Chemical Society 120(22):5509-5516, 1998.
- Jim’enez-Cruz, F. and Laredo, G.C., “Molecular Size Evaluation of Linear and Branched Paraffins from the Gasoline Pool by DFT Quantum Chemical Calculations,” Fuel 83(16):2183-2188, 2004.
- Gun'ko, V.M., Nasiri, R., and Sazhin, S.S., “Effects of the Surroundings and Conformerisation of N-Dodecane Molecules on Evaporation/Condensation Processes,” Journal of Chemical Physics 142(3):034502, 2015.
- Crowe, C.T., Schwarzkopf, J.D., Sommerfeld, M., and Tsuji, Y., “Multiphase Flows with Droplets and Particles,” (Boca Raton, CRC Press, 2011).
- Siebers, D.L., “Scaling Liquid-Phase Fuel Penetration in Diesel Sprays Based on Mixing-Limited Vaporization,” SAE Technical Paper 1999-01-0528, 1999, doi:10.4271/1999-01-0528.