环形燃烧室中圆台斜爆震燃烧特性研究

Combustion Characteristics of Truncated Cone Induced Oblique Detonation Wave in Annular Combustor

关键词:  环形燃烧室  圆台  斜爆震燃烧  波系结构  组合动力

Key words:  Annular combustor  Truncated cone  Oblique detonation combustion  Wave structure  Combined engine

摘要:

面向宽域爆震组合动力发展需求，首次提出适用于轴对称环形流道的圆台诱导斜爆震燃烧组织形式，通过数值模拟验证较低马赫数飞行工况下圆台诱导驻定斜爆震燃烧的可行性以及与斜劈、圆锥斜爆震燃烧的差异，从几何与来流参数两方面研究了圆台诱导斜爆震波的起爆与驻定特性。结果表明：在Ma7飞行工况，相比于圆锥和斜劈，环形燃烧室中圆台可以同时实现斜爆震波的加速起爆与稳定驻定。圆台上游的压缩作用以及下游的膨胀作用，使得圆台斜爆震波存在脱体而不前传的特殊起爆区结构。圆台内径、圆台角度、来流压缩程度以及当量比增大均有利于圆台诱导斜爆震波的起爆。同时，起爆区结构也会出现从渐变到突变再到稳定脱体的变化规律，相应的起爆距离逐渐缩短，爆震波角度逐渐增大。

Abstract:

In order to meet the development requirements of wide-range detonation combined engine， truncated cone induced oblique detonation wave （ODW） combustion structure suitable for axis symmetric annular combustor is proposed for the first time. The feasibility of truncated cone induced stationary ODW combustion and its difference with wedge and conical oblique detonation combustion under flight Mach number 7 were verified by numerical simulation. The initiation and stationary characteristics of truncated cone induced ODW were studied from two aspects of geometry and inflow parameters. The results show that， compared with the cone and wedge， the truncated cone in the annular combustor can realize the acceleration initiation and stationary of ODW at the same time in the low flight Mach number condition. The compression upstream and expansion downstream the truncated cone leads the truncated cone induced ODW showing a special initiation zone structure of detachment without travelling forward. The increase of the inner diameter of the truncated cone， the angle of the truncated cone， the compression degree of incoming flow and the equivalent ratio are all beneficial to the initiation of ODW induced by the truncated cone. At the same time， the structure of the initiation zone also shows a change law from gradual change to abrupt change and then to stable detachment， and the corresponding initiation distance is gradually shortened and the ODW angle is gradually increased.