煤油燃料RBCC亚燃模态掺混与燃烧数值模拟研究

Study on Mixing and Combustion of Kerosene Fuel in Ramjet Mode of RBCC Engine

关键词:  火箭基组合循环  亚燃模态  数值模拟  支板  掺混反应效率  煤油 

Key words:  RBCC  Ramjet mode  Numerical simulation  Pylon  Mixing reaction efficiency  Kerosene

摘要:

为了探索RBCC(Rocket Based Combined Cycle)亚燃模态条件下掺混燃烧性能,对多种工况进行了数值计算。对比分析了各工况下的燃烧室压力、掺混反应效率、总压损失等参数来分析燃烧室内部特性的变化。从数值模拟的研究中可以发现:由于RBCC亚燃模态的特点,一次火箭高温羽流,使得喷注的燃料能够有效地雾化蒸发,通过支板的混合增强作用能有效地提高煤油燃料的掺混能力,凹腔又适当的延长了煤油在燃烧室的停留时间,形成有效的火焰稳定区域,两种有效的火焰稳定方式的结合能实现液体燃料稳定有效的燃烧,而且双凹腔前后组合也能提高燃料的掺混燃烧能力。从计算中还可以发现,合理地布置支板与凹腔的相对位置能提高燃料的掺混反应效率,实现燃料的充分燃烧,并对燃烧性能提高有明显的帮助。

Abstract:

In order to investigate the mixing and combustion in ramjet mode of RBCC engine, some cases were simulated. Chamber pressure, mixing reaction efficiency, total pressure loss etc were compared to study the change of combustion under different cases. The simulation shows that the fuel and airflow are previously heated effectively by rocket flame, which increases the atomization and spray evaporation effect. The pylon enhances the mixing capability of kerosene, and the cavities improve the kerosene residence time in the chamber, the function of pylon and cavities realize the combustion stabilization and effective combustion of liquid fuel. In addition, the dual cavities can also improve the mixing and combustion. Furthermore, the study shows the position between cavities and pylons can improve the mixing reaction efficiency and combustion performance.