底排装置底部压力和回流区特性研究

Numerical Investigation on Base Pressure and Recirculation Region Characteristics of Base Bleed Device

采用标准k-ω湍流模型和有限速率化学反应燃烧模型对二维轴对称雷诺平均N-S方程进行了数值计算,分析了超声速自由来流下冷流和H2-O210组分28步基元燃烧反应的底部排气近尾迹区流场特性,得到了不同排气参数下底部压力和回流区特性,与实验值相吻合。计算结果表明,在较小排气参数下添能比加质更有利于底压提高;随着排气总温的增加,最佳排气参数逐渐减小,回流区逐渐减小;回流区前滞止点位置随着排气参数、排气总温等因素变化而变化,而后滞止点位置几乎不变,但燃烧对回流区前后滞止点均产生了影响。

Numerical simulation was carried out to investigate the base flow field of a base bleed device with non-reacting gas and hydrogen-air combustion,and the combustion mechanism consisted of ten reactive species and twenty-eight reaction steps.The stand k-ω turbulence model and finite-rate chemistry model were employed to calculate the Axisymmetric Reynolds-Averaged Navier-Stokes equations.The computational results of the base pressure and recirculation region characteristics agreed well with the experiments.The calculation shows that the base pressure benefits much more from providing energy than adding injection at the low injection parameter.The optimum injection parameter and recirculation region decreased with the increase of total temperature of the injection gas.The forward stagnation point location of the recirculation region is highly depended on the injection parameter and injection total temperature while they show nearly no differences on the rear stagnation point.The external combustion has effects both on the forward stagnation point and rear stagnation point of the recirculation region.