气体燃料气动火焰稳定器混合特性的初步研究

Preliminary Study on Mixing Characteristics of Gas Fuel Aerodynamic Flame Stabilizer

关键词:  航空发动机  气体燃料  气动火焰稳定器  余气系数  燃烧效率

Key words:  Aero engine  Gas fuel  Aerodynamic flame stabilizer  Air-fuel equivalence ratio  Combustion efficiency

摘要:

为了克服航空发动机加力燃烧室传统钝体火焰稳定器存在的流阻较大、燃烧效率较低和红外辐射偏大的缺点，设计了一种气体燃料气动火焰稳定器，通过喷射气体燃料射流形成气动屏障来产生回流区从而稳定火焰，并采用数值模拟计算和实验测试的方法研究了气体燃料火焰稳定器的混合特性。数值模拟计算表明气动火焰稳定器掺混速度快，可在回流区内形成余气系数比较均匀的混合物,且回流区内余气系数分布随来流和射流的参数变化基本保持恒定不变，实验结果证实了数值模拟的结果，并表明采用气动火焰稳定器的燃烧效率较高，部分工况可达98%以上，可为加力燃烧室火焰稳定器的研究和设计提供参考和依据。

Abstract:

In order to overcome the shortcomings of the traditional bluff body flame stabilizer in the afterburner of the aero-engine, such as the high loss of total pressure, the low combustion efficiency and the high infrared radiation, a gas fuel aerodynamic flame stabilizer is designed, which generates an aerodynamic barrier by injecting a gas fuel jet, and forms a recirculation zone to stabilize the flame. In this article the mixing characteristics of the gas fuel aerodynamic flame stabilizer are studied by numerical simulation and experimental tests. The numerical simulation shows that the aerodynamic flame stabilizer has a fast mixing speed and can form a mixture with a substantially uniform fuel-gas distribution/air-fuel equivalence ratio in the recirculation zone, which does not change a lot with the parameters of air flow and fuel jet. The experimental results confirm the numerical simulation and it show that the combustion efficiency of the aerodynamic flame stabilizer is high enough, at some working conditions up to 98%. This shows a good application prospect in afterburner.