高油气比下燃气分析测温探针反应冻结性能研究

Quenching of Reaction in a Gas-Sampling Probe for Temperature Measurement in High Fuel-to-Air Ratio Combustor

要使用燃气分析法实现燃烧室出口温度分布的高精度测量,需要确保取样探针内燃气样本的化学反应能够快速冻结.随着航空发动机燃烧室出口温度的不断提高,化学反应冻结的难度增加.本研究通过数值模拟与化学反应动力学计算,获得了气动探针内化学反应冻结随当量比和探针落压比的变化规律,分析了探针内部化学反应冻结过程的主要影响因素与机制.研究结果表明,随着当量比增加,探针内CO相对含量的变化量先上升后下降,在当量比为0.9~1.0时最大,达5.2%.随着落压比降低,激波内吞、静温升高,最终将会导致CO、CO_(2)的相对含量的变化量大幅上升.

Effective chemical quenching is needed to ensure the test accuracy of the combustor exit temperature distribution by temperature by gas analysis(TBGA).However,as the exit temperature of the combustor rises,the difficulty in chemical quenching increases.In this research,numerical simulation and chemical reaction calculation were conducted to explore the trends of quench ratio by changing the equivalence ratio and pressure ratio,respectively.The main factors in the quenching process were then analyzed.As the equivalence ratio increases,the CO change ratio increases first and then decreases,with the greatest value of 5.2%at the equivalence ratio of 0.9—1.0.As the pressure ratio decreases,a shockwave pushes back,and the static temperature rises,resulting in a drastic increase in CO and CO_(2) concentrations.