超声速燃烧室小支板对射流作用的数值分析

为分析小支板前/后喷射在超声速燃烧室中的流动特性,运用数值模拟方法研究了小支板对乙烯喷射冷流场的作用规律.对比分析了有无小支板、不同喷射位置、不同喷射角对流场的影响.研究发现小支板增强掺混的机制主要在于在小支板后端形成了流向涡与低压区;在一定范围内,喷孔距离支板尾部越远越处于湍流强度较大的流向涡中,更有利于掺混增强,但同时也距离小支板后缘的低压区更远,这将导致总压损失变大;综合考虑,小支板与喷孔的距离为2.2d,喷射角为90°时燃料穿透深度、混合效率较好,总压损失也相对较小. 

Numerical analysis on effect on injection for supersonic combustor pylon

To analyze of flow characteristics of the pylon before/after injection in supersonic combustion,the numerical simulation was carried out to investigate the effect rules of pylon on ethylene injection cold flow field.The influence of several conditions on flow field was contrastive analyzed,such as: with and without pylon, different injection locations and different injection angles. It is found that the streamwise vortex zone and low pressure depression behind the pylon are the paramount mechanism for mixing enhancement. Further distance between the pylon and injector is good for mixing enhancement for stronger wise vortex zone, but leads to higher total pressure loss for less low pressure depression. Moreover, injection with the distance between pylon and injector of 2.2d, injection angle of 90 degree is recommended regarding high mixing efficiency and less total pressure loss.