【摘要】 作为一种新型燃烧组织方式，氢气微混扩散燃烧可有效防止回火和热声不稳定问题。提出一种基于空气流向涡和氢气射流涡耦合的微混扩散燃烧掺混方案，并采用大涡模拟方法，数值模拟了氢气微混扩散单元的流动燃烧过程和热声特性，明确了火焰扩展至整个流域的全过程，获得了旋涡、温度、组分质量浓度、压力脉动特性等随时间推进的变化规律。结果表明：氢气射流涡以反向旋转涡对的形式向下游传播，扰动主流空气，显著增强掺混质量。所设计的氢气微混扩散燃烧单元在10 000 Hz内未发现热声振荡问题，沿程截面的功率谱密度呈现逐渐降低的趋势，当下游与微混扩散燃烧单元出口之间的轴向距离为85 mm时，响应均小于2 W/Hz。研究成果可为氢气微混扩散燃烧室的设计和工程应用提供重要支撑。更多还原

【Abstract】 As a novel combustion organization method, hydrogen micromix diffusion combustion could effectively prevent flashback and thermoacoustic instability issues. A micromix diffusion combustion mixing scheme based on the coupling of airflow streamwise vortices and hydrogen jet vortices was proposed. Large eddy simulation(LES) was employed to numerically simulate the flow and combustion process of a hydrogen micromix diffusion combustion element, as well as its thermoacoustic characteristics.The entire process from flame ignition to the expansion throughout the entire area was clarified, and the variation patterns of vortices, temperature, species mass concentration, and pressure fluctuations over time were obtained. The research results indicate that the hydrogen jet vortex propagates downstream in the form of counter-rotating vortex pairs, disturbing the mainstream air and significantly enhancing the mixing quality. The designed hydrogen micromix diffusion combustion element did not exhibit thermoacoustic oscillation issues within a frequency range of 10 000 Hz, and the power spectral density along the crosssectional area showed a gradually decreasing trend. At a distance of Δz=85 mm, the response was less than 2 W/Hz. The research findings will provide significant support for the design and engineering application of hydrogen micromix diffusion combustion burners.更多还原