Mixing and Combustion Enhancement in Scramjet Combustors Induced by Interaction between Vortex and Shock Wave

涡流与冲击波相互作用引起超燃冲压发动机燃烧室的混合与强化燃烧

基本信息

批准号：
08455459
负责人：
MASUYA Goro
金额：
$ 4.99万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08455459/
关键词：
Scramjet Supersonic Mixing Supersonic Combustion

项目摘要

In order to establish a method to evaluate relative importance of gain and loss in the available energy to be converted into the propulsive work in the scramjet combustor, we introduced a combustor performance parameter which was written in terms of the kinetic energy efficiency and the combustion efficiency. These two efficiencies in the parameter were combined in the form appearing in the equation for thrust. The combustor performance parameter was evaluated with the available experimental data for two supersonic combustors with eight fuel injection patterns, and it clarified the effects of injection pattern, combustor length, chemical reaction in the nozzle were investigated. The result showed that the optimum combustor length based on the parameter was less than a half of one estimated only from the combustion efficiency or the mixing efficiency. It was found that use of the properties of pure air instead of those of vitiated air used in the experiment may results in significantly … More different value of the performance parameter.As a typical flowfield where interaction between vortices and shock waves occurs, compressible swirling jet of over- or under-expansion condition was chosen, and mixing of such jet was experimentally investigated. At first, non-swirling jet of Mach 0.3, 1.0 or 2.0 was injected into quiescent atmosphere or heated subsonic flow. Mixing characteristics of the non-ideally expanded non-swirling jets could be well correlated with those of the ideally expanded jets when the reference values of diameter and velocity calculated with assumption of expansion or compression to ambient pressure keeping the stream thrust constant were used to non-dimensionalize the data. The swirling jet was produced by attaching a swirler in the subsonic portion of the nozzle. Mixing of the jet was slightly enhanced by increasing swirl number. In comparison with the ideal expansion jet, the potential core region of the non-ideally expanded swirling jet was shortened, but its mixing rate in the developed region was retarded. Effect of swirl on the mixing of two parallel supersonic jets were observed by flow visualization. The swirl enhanced mixing near the merging region of the twin jets. Swirl of the same direction for both jets had resulted in better mixing then that of the counter direction. Less

为了建立一种方法来评估超燃冲压发动机燃烧室中转化为推进功的可用能量的增益和损失的相对重要性，我们引入了一个燃烧室性能参数，该参数用动能效率和燃烧效率来表示这两个参数的效率以推力方程的形式结合起来。燃烧器性能参数通过两种具有八种燃料喷射模式的超音速燃烧器的可用实验数据进行了评估。研究了喷射模式、燃烧室长度、喷嘴内化学反应的影响，结果表明，基于该参数的最佳燃烧室长度小于仅根据燃烧效率或混合效率估计的一半。在实验中使用纯净空气的特性而不是污染空气的特性可能会导致性能参数值显着不同。作为涡流和冲击波之间发生相互作用的典型流场，过流的可压缩旋转射流或者选择欠膨胀条件，对这种射流的混合进行了实验研究。首先，将马赫数为0.3、1.0或2.0的非旋流射流注入静止大气或加热亚音速流中，研究非理想膨胀非旋流的混合特性。当使用在保持流推力恒定的情况下膨胀或压缩到环境压力的假设下计算出的直径和速度的参考值时，旋转射流可以与理想膨胀射流的射流很好地相关。对数据进行无量纲化，通过在喷嘴的亚音速部分安装旋流器，通过增加旋流数来产生旋流射流，与理想的膨胀射流相比，非潜在核心区域。 -理想扩展的旋流射流缩短了，但其在发达区域的混合速率被延迟。通过流动可视化观察旋流对两个平行超音速射流混合的影响。两个喷射流的相同方向的涡流比相反方向的涡流产生更好的混合。