Large Eddy Simulation of a Stagnation Point Reverse Flow Combustor

The complex unsteady behavior of a stagnation point reverse flow combustor (SPRF) is investigated numerically with large eddy simulation (LES) approach using an open source flow solver OpenFOAM. The SPRF combustor has a unique design where inflow and outflow ports are located in the same plane. This feature promotes stable and efficient combustion through internal gas recirculation, and also reveals a complex flow field inside the combustor. Instantaneous flow features, statistical behavior of the turbulent flow, the effect of grid resolution and energy spectrum are evaluated to study the capability of the LES approach for this combustor. The non-reacting cold flow results show overall very good agreement with experimental data, giving confidence that LES with k-equation subgrid model could be a very powerful tool for resolving such complex flow dynamics. Further analyses are extended for reacting cases to examine turbulence combustion interaction. The interaction of the flame with turbulent structures clarified the intense internal gas recirculation mechanism.

Durma Noktasına Sahip Ters Akışlı Yanma Odasının Büyük Edi Benzetimi

Durma noktasına sahip ters akışlı (stagnation point reverse flow, SPRF) yanma odasındaki zamana bağlı kompleks davranışlar büyük edi benzetimi (large eddy simulation, LES) yöntemi kullanılarak açık kaynak kodlu akış çözücüsü OpenFOAM yazılımı ile incelenmiştir. SPRF yanma odasında giriş ve çıkış yüzeyleri aynı düzlemde bulunduğu için tasarım açısından özgün bir yapıya sahiptir. Bu özellik, iç gaz re-sirkülasyonu sağlayarak geometri içerisinde kararlı ve verimli bir yanma sunarken aynı zamanda kompleks bir akış alanını da ortaya çıkarmaktadır. Anlık akış özellikleri, türbülanslı akışın istatistiksel davranışı, eleman ağı çözünürlüğü ve enerji spektrumu, LES yönteminin yanma odasındaki yeterliliğini incelemek açısından değerlendirilmiştir. Reaksiyonun olmadığı soğuk akış analiz sonuçları deneysel veriler ile karşılaştırıldığında deney verilerine oldukça yakın sonuçlar elde edilmiş olup, bu karşılaştırma, LES yöntemi ve k-denklemli grid altı modelinin bu tarz karmaşık akış dinamiklerini çözümlemek konusunda oldukça başarılı bir sonuç ortaya koyduğunu göstermiştir. Türbülans yanma etkileşimini incelemek amacıyla yanma analizleri de ayrıca incelenmiştir. Alevin türbülanslı yapılarla etkileşimi, yoğun iç gaz re-sirkülasyonu mekanizmasını açıklamaktadır.

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[1] A.H. Lefebvre and V.G. McDonell, Atomization and sprays. Boca Raton: CRC Press, 2017.

[2] Y. Neumeier, B. Zinn, Y. Weksler, J.M. Seitzman, J. Jagoda, and J. Kenny, “Ultra-low emissions combustor with non-premixed reactants injection,” in 41st AIAA Joint Propulsion Conference, 2005, paper AIAA-2005-3775.

[3] P. Gopalakrishnan, M.K. Bobba and J.M. Seitzman, “Controlling Mechanisms for Low NOx Emissions in a Non-Premixed Stagnation Point Reverse Flow Combustor,” Proceedings of the Combustion Institute, vol. 31, No. 2, pp. 3401-08, Jan. 2007.

[4] S. Undapalli, S. Srinivasan, and S. Menon, “LES of premixed and non-premixed combustion in a stagnation point reverse flow combustor,” Proceedings of the Combustion Institute, vol. 32, no. 1, pp. 1537–1544, Dec. 2009.

[5] C. Wagner, A. Shishkin, and O. Shishkina, “The use of Direct Numerical Simulations for solving industrial flow problems,” ERCOFTAC Series Direct and Large-Eddy Simulation VIII, pp. 397–404, 2011.

[6] S. B. Pope, Turbulent flows. Cambridge: Cambridge Univ. Pr., 2015. [7] N. Peters, “Multiscale combustion and turbulence,” in Proceedings of the Combustion Institute, vol. 32, No. 1, pp. 1-25, 2009.

[8] T. Poinsot and D. Veynante, Theoretical and Numerical Combustion. 2nd ed. United States of America: R.T. Edwards, Inc., 2005.

[9] F. E. Culick and P. Kuentzmann, “Unsteady motions in combustion chambers for propulsion systems,” Nato Research and Technology Organization Neuilly-Sur-Seine, France, Tech. Rep., 2006.

[10] R. Borghi and S. Murthy, Turbulent reactive flows. Germany: Springer Science & Business Media, 2013.

[11] B. Magnussen and B. Hjertager, “On mathematical modeling of turbulent combustion with special emphasis on soot formation and combustion,” Symposium (International) on Combustion, vol. 16, no. 1, pp. 719–729, 1977.

[12] H. I. Kassem, K. M. Saqr, H. S. Aly, M. M. Sies, and M. A. Wahid, “Implementation of the eddy dissipation model of turbulent non-premixed combustion in OpenFOAM,” International Communications in Heat and Mass Transfer, vol. 38, no. 3, pp. 363–367, 2011.

[13] P. Nordin, “Complex chemistry modelling of diesel spray combustion,” Ph.D. dissertation, Chalmers University of Technology, Dept. of Thermo and Fluid Dynamics, Goteborg, 2001.

[14] P. Senecal, E. Pomraning, K. Richards, T. Briggs, C. Choi, R. McDavid and M. Patterson, “Multi-dimensional modeling of direct-injection diesel spray liquid length and flame lift-off length using CFD and parallel detailed chemistry,” Tech. Rep. SAE Technical Paper. 1997.

[15] C. Duwig and P. Iudiciani, “Large Eddy Simulation of turbulent combustion in a stagnation point reverse flow combustor using detailed chemistry,” Fuel, vol. 123, pp. 256–273, 2014.

[16] S. Menon, P.-K. Yeung, and W.-W. Kim, “Effect of subgrid models on the computed interscale energy transfer in isotropic turbulence,” Computers & Fluids, vol. 25, no. 2, pp. 165–180, 1996.

[17] S. Huang and Q. S. Li, “A new dynamic one-equation subgrid-scale model for large eddy simulations,” International Journal for Numerical Methods in Engineering, vol. 81, No. 7, pp. 835-865, 2010.

[18] J. Chomiak and A. Karlsson, “Flame liftoff in diesel sprays,” Symposium (International) on Combustion, vol. 26, no. 2, pp. 2557–2564, 1996.

[19] S.-C. Kong and R. D. Reitz, “Use of Detailed Chemical Kinetics to Study HCCI Engine Combustion With Consideration of Turbulent Mixing Effects,” Journal of Engineering for Gas Turbines and Power, vol. 124, no. 3, p. 702, 2002.

[20] C.K. Westbrook and F. L. Dryer, “Simplified Reaction Mechanisms for the Oxidation of Hydrocarbon Fuel in Flames,” Combustion Science and Technology, vol. 27, No 1-2, pp. 31-43, Dec. 1981.

[21] H. G. Weller, G. Tabor, H. Jasak and C. Fureby, “A tensorial approach to computational continuum mechanics using object-oriented techniques,” Computers in Physics, vol. 12, No. 6, p. 620, Nov. 1998.

[22] T. Holzmann, Mathematics, Numerics, Derivations and OpenFOAM. Germany: Holzmann CFD, 2016.

[23] P. Gopalakrishnan, S. Undapalli, M. K. Bobba, V. Sankaran, S. Menon, B. Zinn, and J. Seitzman, “Measurements and Modeling of the Flow Field in an Ultra-Low Emissions Combustor,” 44th AIAA Aerospace Sciences Meeting and Exhibit, Sep. 2006, paper AIAA-2006-962.

[24] A. Montorfano, F. Piscaglia, and G. Ferrari, “Inlet boundary conditions for incompressible LES: A comparative study,” Mathematical and Computer Modelling, vol. 57, no. 7-8, pp. 1640–1647, 2013.

[25] N. G. Jacobsen, D. R. Fuhrman, and J. Fredsøe, “A wave generation toolbox for the open-source CFD library: OpenFoam®,” International Journal for Numerical Methods in Fluids, vol. 70, no. 9, pp. 1073–1088, 2011.

[26] D. Karahan, M. Ozgunoglu, S. Karaca and A.G. Gungor, “A large eddy simulation methodology for complex flows,” 8th Ankara International Aerospace Conference, 2015, AIAC-2015-066

[27] J. Jeong and F. Hussain, “On the identification of a vortex,” Journal of Fluid Mechanics, vol. 285, pp. 69–94, 1995.

[28] R. Jahanbakhshi and C.K. Madnia, “The effect of heat release on the entrainment in a turbulent mixing layer,” Journal of Fluid Mechanics, vol. 844, pp. 92–126, Mar. 2018.