| 摘要: |
| 在以双模态冲压发动机为推进装置的高超声速飞行器的加速过程中,燃烧室内的释热量及其分布必须做出相应的调整,使得发动机从亚燃模态转换为超燃模态。在模态转换过程中,由于燃烧室下游边界条件突然从热力壅塞状态变为无壅塞状态,其壁面压力分布会发生明显改变。这将使作用在飞行器上的推力和动量发生突然变化,可能会导致飞行器失去控制。因此,如何实现不同燃烧模态的平稳转换,是燃烧室设计中的技术难点。本文详细介绍了双模态冲压发动机中不同燃烧模态的定义和判定准则、模态转换的实现方式、模态转换的机理,以及在模态转换时可能存在的激波反射结构转换迟滞和火焰结构转换迟滞现象。 |
| 关键词: 双模态冲压发动机 超燃模态 亚燃模态 模态转换 迟滞 |
| DOI： |
| 分类号: |
| 基金项目:双模态冲压发动机模态转换过程中的迟滞问题研究(51276007)。 |
|
| An Overview on Mode Transition in Dual Mode Ramjet |
|
ZHANG Yan1,2, ZHU Shao-hua1, LIU Gang1, LI Xuan1, XU Xu1
|
|
(1. School of Astronautics, Beijing University of Aeronautics and Astronautics,Beijing 100191, China;2. Department of Civil Engineering, Nanyang Institute of Technology, Nanyang 473004, China)
|
| Abstract: |
| A ram-scram transition will occur at some time during the ascent of a hypersonic vehicle powered by a dual-mode ramjet. During this transition, the abrupt change of the downstream boundary condition from the thermally choked condition to the unchoked flow occurs. The ram-scram transition causes a change on the wall static distribution. This leads to a corresponding abrupt change in the thrust force and moments on the vehicle which may result in loss of vehicle control. Consequently, it is paramount important to achieve the smooth mode transition in the design of the combustor. In this paper, the classification of combustion modes, as well as the method and mechanism of mode transition, are introduced in detail. Furthermore, the possible hysteresis phenomena of shock wave reflection and flame structure during the mode transition are also discussed. |
| Key words: Dual Mode Ramjet Scramjet mode Ramjet mode Mode transition Hysteresis |
