甲烷-液氧超临界压力非预混湍流燃烧的数值模拟
收稿日期: 2015-07-08
修回日期: 2015-10-15
网络出版日期: 2015-10-30
基金资助
国家自然科学基金（11372277)
Numerical simulation of CH4-LO<i>x non-premixed turbulent combustion at supercritical pressures
Received date: 2015-07-08
Revised date: 2015-10-15
Online published: 2015-10-30
Supported by
National Natural Science Foundation of China (11372277)
基于雷诺平均Navier-Stokes（RANS）方法和火焰面-反应进度变量湍流燃烧模型，在准确考虑热物性变化和详细化学反应机理的基础上，建立了适用于超临界压力非预混湍流燃烧的数值模型，开展了甲烷-液氧（LOx）超临界压力同轴喷射非预混湍流燃烧过程的数值模拟研究，着重探讨了推进剂混合比分别为1和3情况下超临界工作压力（6～15 MPa）对甲烷-液氧非预混湍流燃烧过程的影响。 结果表明：不同混合比情况下压力对火焰温度和结构的影响会有显著的不同。在推进剂混合比为1时，随着压力的升高，火焰变得更长，且火焰温度升高；而在推进剂混合比为3时，随着压力的升高，火焰长度则会变短。在超临界压力下，火焰沿径向有突然的扩张现象（特别是在6 MPa压力下）。这主要与液氧物性在拟临界温度附近的突变所造成的拟沸腾现象有关，也会受到液氧喷射动量变化的影响。
关键词： 非预混火焰; 湍流燃烧; 超临界压力; 火焰面-反应进度变量; 混合比
汪秋笑 , 黄东欣 , 孟华 . 甲烷-液氧超临界压力非预混湍流燃烧的数值模拟[J]. 航空学报, 2016 , 37(7) : 2132 -2143 . DOI: 10.7527/S1000-6893.2015.0279
A numerical model has been developed for studying non-premixed turbulent combustion at supercritical pressures. The model is based on the Reynolds-averaged Navier Stokes (RANS) equations and the flamelet-progress variable turbulent combustion treatment, and it accommodates accurate calculations of thermophysical properties and a detailed chemical reaction mechanism. It is applied to conduct numerical studies of the coaxial injection and non-premixed turbulent combustion of CH4-LOx at supercritical pressures. The effects of supercritical pressures (6 to 15 MPa) on the combustion processes are examined at different propellant mixture ratios (1 and 3). Results reveal that the effects of pressure on the flame temperature and structure change remarkably at different mixture ratios. At a propellant mixture ratio of 1, the flame length and flame temperature both increase as pressure increases, while at a mixture ratio of 3, the flame length decreases as pressure increases. At a supercritical pressure, the turbulent flame exhibits a sudden expansion in the radial direction (particularly at 6 MPa), because of pseudo boiling resulting from the LOx property anomaly at the pseudo-critical temperature. This phenomenon can also be influenced by the LOx injection momentum.
[1] YANG V. Modeling of supercritical vaporization, mixing, and combustion processes in liquid-fueled propulsion systems[J]. Proceedings of the Combustion Institute, 2000, 28(1):925-942.
[2] HABIBALLAH M, ORAIN M, GRISCH F, et al. Experimental studies of high-pressure cryogenic flames on the mascotte facility[J]. Combustion Science and Technology, 2006, 178(1-3):101-128.
[3] OEFELEIN J C. Mixing and combustion of cryogenic oxygen-hydrogen shear-coaxial jet flames at supercritical pressures[J]. Combustion Science and Technology, 2006, 178(1-3):229-252.
[4] CANDEL S, JUNIPER M, SINGLA G, et al. Structure and dynamics of cryogenic flames at supercritical pressures[J]. Combustion Science and Technology, 2006, 178(1-3):161-192.
[5] 王维彬, 孙纪国. 航天动力发展的生力军--液氧甲烷火箭发动机[J]. 航天制造技术, 2011(2):3-6. WANG W B, SUN J G. The powerhouse of the space dynamic development-LO<i>x/CH4rocket engine[J]. Aerospace Manufacturing Technology, 2011(2):3-6(in Chinese).
[6] 丰松江, 王富, 聂万胜. 新型低温火箭发动机超临界燃烧研究进展[J]. 导弹与航天运载技术, 2009(6):23-27. FENG S J, WANG F, NIE W S. The development of new type cryogenic rocket engine combustion at supercritical pressure[J]. Missiles and Space vehicles, 2009(6):23-27(in Chinese).
[7] PONS L, DARABIHA N, CANDEL S G, et al. Mass transfer and combustion in transcritical non-premixed counterflows[J]. Combustion Theory and Modelling, 2009, 13(1):57-81.
[8] WANG X J, HUO H F, YANG V. Supercritical combustion of general fluids in laminar counterflows:AIAA-2013-1165[R]. Reston:AIAA, 2013.
[9] SINGLA G, SCOUFLAIRE P, ROLON C, et al. Transcritical oxygen/transcritical or supercritical methane combustion[J]. Proceedings of the Combustion Institite, 2005, 30(2):2921-2928.
[10] KIM T, KIM Y, KIM S. Effects of pressure and inlet temperature on coaxial gaseous methane/liquid oxygen turbulent jet flame under transcrirical conditions[J].The Journal of Supercritical Fluids, 2013, 81:164-174.
[11] ZONG N, YANG V. Near-field flow and flame dynamics of LOX/methane shear-coaxial injector under supercritical conditions[J]. Proceedings of the Combustion Institute, 2007, 31(2):2309-2317.
[12] YU J, MENG H. A numerical study of counterflow diffusion flames of methane/air at various pressures[J]. Sci China Tech Sci, 2014, 57(3):615-624.
[13] MENG H, HSIAO G C, YANG V, et al. Transport and dynamics of liquid oxygen droplets in supercritical hydrogen streams[J]. Journal of Fluid Mechanics, 2005, 527:115-139.
[14] MENG H, YANG V. A unified treatment of general fluid thermodynamics and its application to a preconditioning scheme[J]. Journal of Computational Physics, 2003, 189(1):277-304.
[15] XU K, MENG H. Analyses of surrogate models for calculating thermophysical properties of aviation kerosene RP-3 at supercritical pressures[J]. Sci China Tech Sci, 2015, 58(3):510-518.
[16] REID R C, PRAUSNITZ J M, POLING B E. The properties of gases and liquids[M]. 4th ed. New York:McGraw-Hill, 1987:587-588.
[17] TAKAHASHI S. Preparation of a generalized chart for diffusion coefficients of gases at high pressures[J]. Journal of Chemical Engineering of Japan, 1974, 7(6):417-420.
[18] PIERCE C D, MOIN P. Progress-variable approach for large-eddy simulation of non-premixed turbulent combustion[J]. Journal of Fluid Mechanics, 2004, 504:73-97.
[19] SMITH G P, GOLDEN D M, FRENKACK M, et al. Available at http://www.me.berkeley.edu/gri_mech/.
[20] National Institute of Standards and Technology. Thermophysical properties of fluid systems[DB/OL]. (2009-03-21)[2015-07-08]. http://webbook.nist.gov/chemistry/fluid.
[21] LIAN C, MERKLE C L. Contrast between steady and time-averaged unsteady combustion simulations[J]. Computers & Fluids, 2011, 44(1):328-338.
/
| 〈 |
|
〉 |
CJA