Abstract
Accurate modelling of spray combustion process is essential for efficiency improvement and emissions reduction in practical combustion engines. In this work, both unsteady Reynolds-averaged Navier-Stokes (URANS) simulations and large eddy simulations (LES) are performed to investigate the effects of spray and turbulence modelling on the mixing and combustion characteristics of an n-heptane spray flame in a constant volume chamber at realistic conditions. The non-reacting spray process is first simulated with URANS to investigate the effects of entrainment gas-jet model on the penetration characteristics and fuel vapor distributions. It is found that the droplet motion near the nozzle has significant influence on the fuel vapor distribution, while the liquid penetration length is controlled by the evaporation process and insensitive to gas-jet model. For the case considered, both URANS with the gas-jet model and large eddy simulations can properly predict the vapor penetration. For the combustion characteristics, it is found that LES yields better predictions in the global combustion characteristics. The URANS with gas jet model yields a comparable flame length and lift-off-length (LOL) to LES, but results in a larger ignition delay time compared to the experimental data. Another focus of this work is to qualify the convergence characteristics of the dynamic adaptive chemistry (DAC) method in these transient combustion simulations, where DAC is applied to reduce the mechanism locally and on-the-fly to accelerate chemistry calculations. The instantaneous flame structures and global combustion characteristics such as ignition delay time, flame lift-off length and emissions are compared between simulations with and without DAC. For URANS, good agreements are observed both on instantaneous flame structures and global characteristics. For LES, it is shown that the errors incurred by DAC are small for scatter distributions in composition space and global combustion characteristics, while they may significantly affect instantaneous flame structures in physical space. The study reveals that for DAC application in transient simulations, global or statistic information should be used to assess the accuracy, such as manifolds in composition space, conditional quantities and global combustion characteristics. For the cases investigated, a speed-up factor of more than two is achieved by DAC with a 92-species skeletal mechanism with less than 0.2 % and 3.0 % discrepancy in ignition delay and LOL, respectively.
Article PDF
Similar content being viewed by others
Explore related subjects
Discover the latest articles, news and stories from top researchers in related subjects.Avoid common mistakes on your manuscript.
References
Jiang, X., Siamas, G.A., Jagus, K., Karayiannis, T.G.: Physical modelling and advanced simulations of gas–liquid two-phase jet flows in atomization and sprays. Prog. Energy Combust. Sci. 36, 131–167 (2010)
Idicheria, C.A., Pickett, L.M: Effect of EGR on diesel premixed-burn equivalence ratio. Proc. Combust. Inst. 31(2), 2931–2938 (2007)
Pickett, L., Bruneaux, G.: Engine combustion network, Combustion research facility, Sandia national laboratories, Livermore, CA. See http://www.sandia.gov/ECN (2011)
Zhou, L., Luo, K.H., Qin, W., Jia, M., Shuai, S.J.: Large eddy simulation of spray and combustion characteristics with realistic chemistry and high-order numerical scheme under diesel engine-like conditions. Energy Convers. Manag. 93(0), 377–387 (2015)
Zhou, L., Ren, Z., Lu, Z., Lu, T., Luo, K.: Large-eddy simulations of an n-heptane spray flame with dynamic adaptive chemistry. SAE Int. J. Engines 8(2), 447–454 (2015)
Pei, Y., Hawkes, E.R., Kook, S.: Transported probability density function modelling of the vapour phase of an n-heptane jet at diesel engine conditions. Proc. Combust. Inst. 34(2), 3039–3047 (2013)
Bhattacharjee, S., Haworth, D.C: Simulations of transient n-heptane and n-dodecane spray flames under engine-relevant conditions using a transported PDF method. Combustion and Flame 160(10), 2083–2102 (2013)
Som, S., Longman, D.E., Luo, Z., Plomer, M., Lu, T., Senecal, P.K., Pomraning, E.: Simulating flame lift-off characteristics of diesel and biodiesel fuels using detailed chemical-kinetic mechanisms and large eddy simulation turbulence model. J. Energy Resour. Technol. 134(3), 1–10 (2012)
Bekdemir, C., Somers, L.M.T, de Goey, L.P.H., Tillou, J., Angelberger, C.: Predicting diesel combustion characteristics with Large-Eddy Simulations including tabulated chemical kinetics. Proc. Combust. Inst. 34(2), 3067–3074 (2013)
Bottone, F., Kronenburg, A., Gosman, D., Marquis, A.: The numerical simulation of diesel spray combustion with LES-CMC. Flow, Turbul. Combust. 89(4), 651–673 (2012)
Vishwanathan, G., Reitz, R.D: Development of a practical soot modeling approach and its application to low-temperature diesel combustion. Combust. Sci. Technol. 182 (8), 1050–1082 (2010)
Lucchini, T., d’Errico, G., Ettorre, D., Ferrari, G.: SAE technical paper (2009)
Azimov, U., Kim, K.-S., Bae, C.: Modeling of flame lift-off length in diesel low-temperature combustion with multi-dimensional CFD based on the flame surface density and extinction concept. Combustion Theory and Modelling 14(2), 155–175 (2010)
Zhou, L., Lu, Z., Ren, Z., Lu, T., Luo, K.: Numerical analysis of ignition and flame stabilization in an n-heptane spray flame, International Journal of Heat and Mass Transfer 88, 565–571 (2015)
Post, S., Iver, V., Abraham, J.: A study of near-field entrainment in gas jets and sprays under diesel conditions. J. Fluids Eng. 122(2), 385–395 (2000)
Beard, P., Duclos, J.-M., Habchi, C., Bruneaux, G., Mokaddem, K., Baritaud, T.: Extension of Lagrangian-Eulerian spray modeling: application to high-pressure evaporating diesel sprays. SAE Trans. 109(4), 1417–1434 (2000)
Beard, P., Colin, O., Miche, M.: Improved modelling of DI diesel engines using sub-grid descriptions of spray and combustion. SAE Trans. 112(3), 73–86 (2003)
Abraham, J.: Entrapment characteristics of transient gas jets. Numerical Heat Transfer Part A Applications 30(4), 347–364 (1996)
Curran, H.J., Gaffuri, P., Pitz, W.J., Westbrook, C.K.: A comprehensive modeling study of iso-octane oxidation. Combustion and Flame 129(3), 253–280 (2002)
Curran, H.J., Gaffuri, P., Pitz, W.J., Westbrook, C.K.: A comprehensive modeling study of n-heptane oxidation. Combustion and Flame 114(1–2), 149–177 (1998)
Lu, T., Law, C.K: Toward accommodating realistic fuel chemistry in large-scale computations. Prog. Energy Combust. Sci. 35(2), 192–215 (2009)
Pope, S.B.: Small scales, many species and the manifold challenges of turbulent combustion. Proc. Combust. Inst. 34(1), 1–31 (2013)
Pope, S.B., Ren, Z: Efficient implementation of chemistry in computational combustion. Flow, Turbulence and Combustion 82(4), 437–453 (2009)
Bilger, R., Pope, S., Bray, K., Driscoll, J.: Paradigms in turbulent combustion research. Proc. Combust. Inst. 30(1), 21–42 (2005)
Law, C.K.: Combustion physics. Cambridge University Press, New York (2006)
Peters, N.: Turbulent combustion. Cambridge University Press (2000)
Tomlin, A.S., Turányi, T., Pilling, M.J.: Mathematical tools for the construction, investigation and reduction of combustion mechanisms. Comprehensive chemical kinetics 35, 293–437 (1997)
Warnatz, J., Maas, U., Dibble, R.W.: Combustion: Physical and chemical fundamentals, modeling and simulation, experiments, pollutant formation: Springer (2006)
Liang, L., Stevens, J.G., Farrell, J.T.: A dynamic adaptive chemistry scheme for reactive flow computations. Proc. Combust. Inst. 32(1), 527–534 (2009)
Yang, H., Ren, Z., Lu, T., Goldin, G.M.: Dynamic adaptive chemistry for turbulent flame simulations. Combustion Theory and Modelling 17(1), 167–183 (2013)
Liang, L., Stevens, J.G., Raman, S., Farrell, J.T.: The use of dynamic adaptive chemistry in combustion simulation of gasoline surrogate fuels. Combustion and Flame 156(7), 1493–1502 (2009)
Shi, Y., Liang, L., Ge, H.-W., Reitz, R.D.: Acceleration of the chemistry solver for modeling DI engine combustion using dynamic adaptive chemistry (DAC) schemes. Combustion Theory and Modelling 14(1), 69–89 (2010)
Tosatto, L., Bennett, B.A.V., Smooke, M.D.: A transport-flux-based directed relation graph method for the spatially inhomogeneous instantaneous reduction of chemical kinetic mechanisms. Combustion and Flame 158(5), 820–835 (2011)
Contino, F., Foucher, F., Dagaut, P., Lucchini, T., D’Errico, G., Mounaïm-Rousselle, C.: Experimental and numerical analysis of nitric oxide effect on the ignition of iso-octane in a single cylinder HCCI engine. Combustion and Flame 160 (8), 1476–1483 (2013)
Lu, T., Law, C.K: A directed relation graph method for mechanism reduction. Proc. Combust. Inst. 30(1), 1333–1341 (2005)
Lu, T., Law, C.K: On the applicability of directed relation graphs to the reduction of reaction mechanisms. Combustion and Flame 146(3), 472–483 (2006)
Pepiot-Desjardins, P., Pitsch, H.: An efficient error-propagation-based reduction method for large chemical kinetic mechanisms. Combustion and Flame 154(1–2), 67–81 (2008)
Sun, W., Chen, Z., Gou, X., Ju, Y.: A path flux analysis method for the reduction of detailed chemical kinetic mechanisms. Combustion and Flame 157(7), 1298–1307 (2010)
Oluwole, O.O., Ren, Z., Petre, C., Goldin, G.: Decoupled species and reaction reduction: An error-controlled method for dynamic adaptive chemistry simulations. Combustion and Flame 162(5), 1934–1943 (2015)
Alamos, L.: KIVA-3V: A block-structured Kiva program for engines with vertical or canted values.LA-18818-MS,1997
Van Leer, B.: Towards the ultimate conservative difference scheme. II. Monotonicity and conservation combined in a second-order scheme. J. Comput. Phys. 14(4), 361–370 (1974)
Sone, K., Menon, S.: Effect of subgrid modeling on the in-cylinder unsteady mixing process in a direct injection engine. J. Eng. Gas Turbines and Power-Transactions of the Asme 125(2), 435–443 (2003)
Patterson, M.A., Reitz, R.D.: Modeling the effects of fuel spray characteristics on diesel engine combustion and emission. Fuel 1998, 09–05 (2013)
O’Rourke, P.J.: Collective drop effects on vaporizing liquid sprays: Princeton University (1981)
Zhou, L., Xie, M.Z., Jia, M.: Influences of subgrid turbulent kinetic energy and turbulent dispersion on the characteristics of fuel spray, SAE: 2011-01-1839 (2011)
Bharadwaj, N., Rutland, C., Chang, S.: Large eddy simulation modelling of spray-induced turbulence effects. Int. J. Eng. Res. 10(2), 97–119 (2009)
Yoo, C.S., Lu, T., Chen, J.H., Law, C.K.: Direct numerical simulations of ignition of a lean n-heptane/air mixture with temperature inhomogeneities at constant volume: Parametric study. Combustion and Flame 158(9), 1727–1741 (2011)
Li, Y., Jia, M., Liu, Y., Xie, M.: Numerical study on the combustion and emission characteristics of a methanol/diesel reactivity controlled compression ignition (RCCI) engine. Appl. Energy 106, 184–197 (2013)
Lee, C.H., Wang, Y., Reitz, R.D.: CFD simulation of diesel sprays over a wide range of ambient gas densities using an improved gas jet spray model. Atomization and Sprays 21(7), 591–609 (2011)
Kokjohn, S.L., Reitz, R.D.: Investigation of the roles of flame propagation, turbulent mixing, and volumetric heat release in conventional and low temperature diesel combustion. Journal of Engineering for Gas Turbines and Power 133(10), 1–10 (2011)
Abani, N., Reitz, R.D.: Unsteady turbulent round jets and vortex motion. Phys. Fluids (1994-present) 19(12), 125–102 (2007)
Ren, Z., Liu, Y., Lu, T., Lu, L., Oluwole, O.O., Goldin, G.M.: The use of dynamic adaptive chemistry and tabulation in reactive flow simulations. Combustion and Flame 161(1), 127–137 (2014)
Tosatto, L., Bennett, B., Smooke, M.: A transport-flux-based directed relation graph method for the spatially inhomogeneous instantaneous reduction of chemical kinetic mechanisms. Combustion and Flame 158(5), 820–835 (2011)
Hori, T., Senda, J., Kuge, T., Fujimoto, H.G.: Large eddy simulation of non-evaporative and evaporative diesel spray in constant volume vessel by use of KIVALES. Measurement 1, 3337 (2006)
Zhou, L., Xie, M., Luo, K.H., Jia, M., Zhou, Q., Liu, H.: SAE Technical Paper (2013)
Lu, L., Lantz, S.R., Ren, Z., Pope, S.B.: Computationally efficient implementation of combustion chemistry in parallel PDF calculations. J. Comput. Phys. 228(15), 5490–5525 (2009)
Zhou, L., Xie, M.-Z., Jia, M., Shi, J.-R.: Large eddy simulation of fuel injection and mixing process in a diesel engine. Acta Mechanica Sinica 27(4), 519–530 (2011)
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Lu, Z., Zhou, L., Ren, Z. et al. Effects of Spray and Turbulence Modelling on the Mixing and Combustion Characteristics of an n-heptane Spray Flame Simulated with Dynamic Adaptive Chemistry. Flow Turbulence Combust 97, 609–629 (2016). https://doi.org/10.1007/s10494-015-9702-5
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10494-015-9702-5