燃料预加热对超声速剪切掺混的增强效果  

Enhancement Effect of Fuel Preheating on Supersonic Shear Mixing

作　　者：段艳娟[1] 杨玉新[1] 黄礼铿 李欣 章思龙 DUAN Yanjuan;YANG Yuxin;HUANG Likeng;LI Xin;ZHANG Silong(Xi'an Aerospace Power Technology Research Institute,The Fourth Research Institute of China Aerospace Science and Technology Corporation,Xi'an 710025,China;School of Energy Science and Engineering,Harbin Institute of Technology,Harbin 150001,China)

机构地区：[1]中国航天科技集团公司第四研究院西安航天动力技术研究所,西安710025 [2]哈尔滨工业大学能源科学与工程学院,哈尔滨150001

出　　处：《南京航空航天大学学报》2023年第5期827-838,共12页Journal of Nanjing University of Aeronautics & Astronautics

基　　金：国家自然科学基金面上项目(52176037)。

摘　　要：随着高超声速飞行器不断朝着高马赫、宽速域方向发展,推进系统面临低动压的工作条件,对燃烧室内的流动掺混带来巨大挑战。针对碳氢燃料超燃冲压发动机燃烧室,本文研究了碳氢燃料预加热对超声速剪切掺混特性的影响机制,分析了温度与碳氢燃料热裂解对掺混特性的影响规律。研究发现,当碳氢燃料未发生热裂解反应时,燃料预加热会使射流黏性耗散增强从而掺混效率降低,燃料温度从750 K增加到900 K时,燃烧室掺混效率降低约5%、总压损失约增加20%;但燃料热裂解反应对剪切掺混有双重影响,裂解后的碳氢燃料膨胀性能提升,使喷嘴附近的掺混效率提高约18%;由于剪切层内流体湍动能下降,在远离喷嘴的位置掺混效率降低约6%。With the continuous development of hypersonic aircraft towards high Mach and wide speed domains,the propulsion system faces low dynamic pressure working conditions,leading to a huge challenge to the flow mixing in the combustion chamber.The influence mechanism of hydrocarbon fuel preheating on supersonic shear mixing characteristics in the scramjet combustor was studied,and the influence of temperature and hydrocarbon fuel pyrolysis on mixing characteristics was analyzed.It is found that the preheating of non-cracking hydrocarbon fuel will enhance the viscous dissipation of the jet and reduce the mixing efficiency.When the fuel temperature increases from 750 K to 900 K,the mixing efficiency of the combustion chamber will decrease by nearly 5%,and the total pressure loss will increase by about 20%.However,the thermal cracking reaction of hydrocarbon fuel has a dual effect on the shear mixing.The expansion performance of the cracked hydrocarbon fuel is improved,and the mixing efficiency near the nozzle is increased by about 18%;However,due to the decrease in turbulent kinetic energy of the fluid in the shear layer,the mixing efficiency decreases by about 6%at a position far from the nozzle.

关 键 词：预加热 超声速燃烧室 剪切掺混 碳氢燃料 热裂解 

分 类 号：V231.1[航空宇航科学与技术—航空宇航推进理论与工程]