中心锥对旋转爆轰发动机内外流场影响的三维数值模拟研究

Three Dimensional Numerical Simulation of Effects of Aerospike on Internal and External Flow Field of Rotating Detonation Engine

关键词:  旋转爆轰发动机  燃烧室  流场  数值模拟  中心锥  波系结构  推进性能

Key words:  Rotating detonation engine  Combustor  Flow field  Numerical simulation  Aerospike  Wave structure  Propulsive performance

摘要:

为探究中心锥对旋转爆轰发动机（Rotating detonation engine，简称RDE）内外流场结构与推进性能的影响，设计了90°，60°，45°，30°，20°，14°锥角与基准结构7种构型，对燃烧室内径为78mm、外径为88mm、长度为100mm的RDE进行三维数值模拟，获得了各构型下详尽的流场参数。结果表明：在本文构型下中心锥对内流场影响很小，各构型的内流场参数与结构基本一致；中心锥对外流场的爆轰产物有轴向加速与径向吸附作用，能够调控尾部区域的流场特性；中心锥对由压差项产生的推力具有显著的提升效果，最佳推力性能出现在20°中心锥构型中，RDE总推力增益达22.8%。研究结果揭示了中心锥对RDE推力影响的作用机理，阐明了锥角对推进性能的影响规律，对带锥形构型的尾喷管设计工作提供了参考。

Abstract:

In order to explore the effects of aerospike on the internal and external flow field structure and propulsion performance of Rotating Detonation Engine （RDE）， seven configurations with angles of 90°， 60°， 45°， 30°， 20°， 14° and reference configuration were designed. The combustion chamber with inner diameter of 78mm， outer diameter of 88mm and length of 100mm was numerically simulated， and the detailed flow field parameters under each configuration were obtained. The results show that aerospike has little effect on the internal flow field， and the parameters as well as the structure of internal flow field of each configuration are basically consistent. The aerospike has the effect of axial acceleration and radial adsorption on the detonation products of external flow field， which can change the structure of the external flow field. Aerospike can significantly increase the thrust generated by the pressure term， with the maximum one occurring in the configuration of 20°， the total thrust gain of RDE is 22.8%. The results reveal the mechanism of the influence of aerospike on RDE thrust， clarify the law of the influence of aerospike angle on propulsion performance， and provide a reference for the design of nozzle with conical configuration.