圆形燃烧室支板火箭超燃冲压发动机数值模拟

摘要

For increasing the ability of ignition and flame holding of large scale scramjet, the strut-rocket scramjet is developed, which consists of main strut in isolator, strut rocket and circular combustor. The numerical simulation including multi-steps chemical mechanisms was developed to investigate the reactive flow characteristics for liquid hydrocarbon supersonic combustion in circular combustor strut-rocket scramjet which is combined with pylons and cavity. It is indicated that the combination of strut-rocket and pylons is the paramount mechanism for flame holding. The results show that the strut-rocket scramjet can provide robust ignition and combustion efficiency and wide operability for ambient liquid hydrocarbon fuel in large scale combnstor.%为了提高大尺寸超燃冲压发动机的掺混燃烧和火焰稳定能力,提出了以中心主支板和支板火箭进行点火和火焰稳定的超燃冲压发动机基本结构,采用轴对称的圆形燃烧室以及小支板和凹腔等混合增强方式,通过包含多步简化动力学的数值模拟方法,研究了支板、凹腔结构与圆形燃烧室的不同匹配关系.结果表明,隔离段中心主支板能有效提高燃料与空气的掺混度,支板火箭的富燃高温羽流在不同状态下均能实现可靠点火;圆形燃烧室结合多组小支板和凹腔能进一步增强燃料混合和高效燃烧.利用支板火箭与轴对称圆形燃烧室相结合能在较短燃烧室内实现高效燃烧,为将来开展大尺寸超燃冲压发动机燃烧技术研究奠定基础.