Gas-liquid two phase detonation properties in an engine detonation chamber
Received date: 2016-07-18
Online published: 2018-06-27
利用爆轰波产生周期性冲量是脉冲爆震发动机推进系统的关键.建立非定常两相爆轰的Eulerian-Lagrangian模型, 以正庚烷液体燃料为例,采取高分辨率的MUSCL(monotonic upwind scheme for conservation law)格式,针对发动机爆震室气液两相爆轰的热力、动力学性质展开数值研究,计算所得的爆轰波压力与实验结果较为一致, 且基于较小粒径的燃料液滴(25 $\mu $m), 计算爆轰波C-J(Chapman-Jouguet)状态对应的爆轰参数与理论值接近,验证了建立的模型和研究方法是正确的. 同时,讨论爆轰管内燃料液滴粒径对爆轰波参数的影响. 结果显示, 在均匀预混时,液滴破碎蒸发域宽度仅与燃料初始粒径有关. 随着燃料初始粒径的增大,液滴破碎蒸发域宽度增加, 且两者存在线性关系. 同时,当燃料初始粒径从25 $\mu $m增大至100 $\mu $m,爆轰波反应区宽度增大了240 %, 而爆轰的压力峰值从7.08 MPa降低至5.14 MPa.
王晨辰, 翁培奋, 丁珏, 李家骅, 陈永杰 . 发动机爆震室气液两相爆轰性质[J]. 上海大学学报(自然科学版), 2018 , 24(3) : 402 -411 . DOI: 10.12066/j.issn.1007-2861.1848
Periodic impulse generated by detonation waves is a key for a pulse detonation engine. To simulate inhomogeneous two-phase detonation, a new two-dimensional Eulerian-Lagrangian model that includes two-way coupling between gas and droplet phases is presented. Detonation of n-heptane in air/oxygen is simulated using the high resolution monotonic upwind scheme for conservation laws (MUSCLs) scheme to study thermodynamic and dynamic properties of two phase detonation. The computed detonation wave pressure is in agreement with experimental results. Based on the fuel droplets with a smaller particle size (25 $\mu $m), the computed detonation parameters corresponding to the Chapman-Jouguet (C-J) state are close to the theoretical values. It verifies the model and the research method established in this paper. Moreover, effects of droplet sizes on the detonation process are discussed. The results show that droplet break and the evaporation domain is related to the droplet size for uniform premixing. As the initial particle size of the fuel increases, the liquid droplet breaks and the evaporation domain width increases, with linear relationship between them. When the initial particle size of the fuel is increased from 25 $\mu $m to 100 $\mu $m, the width of the reaction zone is increased by 240 %, and the peak pressure of detonation is decreased from 7.08 MPa to 5.14 MPa.
| [1] | Gabrijel Z, Nicholls J A. Cylindrical heterogeneous detonation waves[J]. Acta Astronautica, 1978,5:1051-1061. |
| [2] | Dabora E K. A model for spray detonation[J]. Acta Astronautica, 1978,6:269-280. |
| [3] | 洪滔, 秦承森. 气体-燃料液滴两相系统爆轰的数值模拟[J]. 爆炸与冲击, 1999,19(4):336-342. |
| [4] | 丁珏, 应梦侃. 基于两相流模型数值研究可燃颗粒燃烧爆轰的特性[J]. 中国安全生产科学技术, 2014,10(3):17-20. |
| [5] | 马丹花, 翁春生. 二相湍流爆轰流场的数值仿真[J]. 计算机仿真, 2012,29(6):85-88. |
| [6] | 许厚谦, 于强. 激波点燃粉尘的数值模拟研究[J]. 爆炸与冲击, 1994,14(4):290-297. |
| [7] | Cheatham S, Kailasanath K. Multi-phase detonations in pulse detonation engines [C]// AIAA Aerospace Sciences Meeting and Exhibit. 2006. |
| [8] | 蒋弢, 翁春生. 气液两相脉冲爆轰发动机的建模和仿真[J]. 计算机仿真, 2012,29(8):77-80. |
| [9] | Westbrook C K, Dryer F L. Simplified reaction mechanisms for the oxidation of hydrocarbon[J]. Combustion Science and Technology, 1981,27:31-43. |
| [10] | Westbrook C K, Dryer F L. Simplified reaction mechanisms for the oxidation of hydrocarbon fuels in flames[J]. Combustion Science and Technology, 1981,27:31-43. |
| [11] | Golovitchev V I, Chomiak J. Evaluation of ignition improvers for methane auto-ignition[J]. Combustion Science and Technology, 1998,135:31-47. |
| [12] | Golovitchev V I, Nordin N, Chomiak J. Numerical modeling of hydrogen deflagration in multi-room compartments[J]. Proceedings of the Computational Technologies for Fluid/Thermal/Chemical Systems with Industrial Applications, 1998,377(2):169-176. |
| [13] | Van Leer B. Towards the ultimate conservative difference scheme. V. a second-order sequel to Godunov's method[J]. Journal of Computational Physics, 1979,32(1):101-136. |
| [14] | 洪滔. 两相爆轰的理论和数值研究[D]. 绵阳: 中国工程物理研究院, 2004: 38-39. |
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