高体积力场下火焰加速现象的数值研究

Numerical study of flame acceleration phenomenon in high body force field

近现代航空燃气涡轮发动机的发展一直聚焦于提高推重比和降低耗油率,对燃烧室以及相关燃烧技术进行理论创新是关键内容之一。为了更好地在航空发动机燃烧室中利用新型超重力燃烧技术,以瑞利泰勒不稳定性为切入点对超重力燃烧进行了数值机理研究,针对旋转管内的超重力预混燃烧进行了二维非稳态数值模拟。研究表明,圆管旋转所带来的离心力场可以加快火焰传播速度,进一步分析表明离心力诱发了火焰面强烈的瑞利泰勒不稳定性,使得火焰面面积增加,并提高了火焰整体的反应强度和传播速度。结合数值模拟结果与理论公式分析,初步明确了超重力燃烧的不同阶段和各阶段的主导因素。研究结论可以支持超紧凑燃烧室的设计,指导从瑞利-泰勒不稳定性的角度对超紧凑燃烧室内的超重力燃烧进行分析及优化。

The development of modern aero turbine engine focuses on improving thrust-to-weight ratio and thrust-specific-fuel-consumption.To meet the above goal,innovations should be achieved in research of the core in aero engine,the combustor and combustion technique.For the sake of advanced combustor,the mechanism of high-g combustion was studied.Considering Rayleigh-Taylor instability,a 2D unsteady simulations were conducted to qualitatively and quantitatively analyze the mechanism of premixed flame propagation in a rotating tube.The result shows that the body force acting on the flame surface could induce the Rayleigh-Taylor instability enlarging the flame surface area,improving the reaction rate,and accelerating the flame speed.Based on the theoretical equations and current simulation results,the high-g combustion was divided into different phases and the leading mechanism of each phase was analyzed.The research could provide a reference for the further design of an ultra-compact combustor.