双模态超燃冲压发动机燃烧室数值模拟

【作者】 王靛；

【导师】 蔡元虎；

【作者基本信息】 西北工业大学 ， 航空宇航推进理论与工程， 2004， 硕士

【摘要】 双模态冲压发动机是综合了亚燃冲压发动机和超燃冲压发动机优势的一种新型的吸气式动力装置，它可以在比较宽广的飞行马赫数范围内工作(M≈3～8)，具有良好的工作性能和广阔的应用前景。 双模态燃烧室是双模态超燃冲压发动机中最关键的部件和设计难点。本文采用MacCormack显式时间分裂法、B-L代数涡粘性湍流模型及氢-空气两步非平衡化学动力学反应模型，模拟了在不同的飞行马赫数条件下，固定几何的双模态燃烧室在不同供油规律下的二维燃烧流场。 计算研究表明，在相同的来流条件下，供油规律对燃烧室的工作模态有着重大的影响；在不同的来流条件下，可以通过调节供油规律使燃烧室分别实现亚燃模态和超燃模态；隔离段对防止燃烧引起的压力升高对进气道的干扰和燃烧室的模态转换具有重要的作用。更多还原

【Abstract】 Dual-Mode ramjet engine which gathers the advantages of both ramjet and scramjet is a new-style airbreathing propulsion device. It can operate over a wide Mach number ranges(M=3-8). It is of remarkable performance and great potential application for hypersonic vehicle.Dual-Mode combustion chamber ,as the key component of the Scramjet, is the most difficult to design. In this paper, MacCormack explicit time-split scheme ,Baldwin-Lomax algebraic turbulent model and two-steps hydrogen-air nonequilibrium chemical kinetics model are employed to simulate the 2-D flow fields in a fixed geometry scramjet combustor in different injecting way of fuel in different flight conditions.The results show, in the same entrance condition , the operating mode of scramjet combustor is influenced by the control of fuel . Scramjet combustor may realize the subsonic-combustion mode and supersonic-combustion mode respectively based on the control of fuel in variable flight conditions. Isolator has great effect on mode transition and preventing unstart of inlet. Inlet can be unstarted by raising the back pressure result from chemical energy release in the combustor.更多还原