径向冷却通道长度对气冷稳定器气动热力性能的影响

Effects of Radial Cooling Channel Length on Aero-Thermodynamic Performance of Air Cooled Flameholder

关键词:  径向冷却通道长度  气冷稳定器  冷态流场  冷却性能  热混合效率  流动损失

Key words:  Radial cooling channel length  Air cooled flameholder  Cold flow field  Cooling performance  Thermal mixing efficiency  Flow loss

摘要:

为了获得冷态下径向冷却通道长度对新型跨流式气冷稳定器气动热力性能的影响，基于Navier-Stokes方程，对在额定工况下5组不同径向冷却通道长度的该气冷稳定器模型进行了三维流固耦合传热数值模拟研究，得到了气冷稳定器外部流场、径向稳定器外壁面的冷却效率、加力燃烧室热混合效率和总压恢复系数的变化规律。在研究的参数范围内，结果表明:径向冷却通道长度的增加，首先，加强了气冷稳定器后的湍流掺混，使得回流区内湍动能极大值增加了24.3%；其次，会减弱径向稳定器近中心锥处的外壁面冷却效果，导致径向稳定器迎风侧外壁面平均冷却效率降低了14.4%；随着径向冷却通道长度的增加，加力燃烧室沿程热混合效率分布曲线随之向上移动；加力燃烧室沿程总压恢复系数分布曲线随之向下移动，加力燃烧室出口总压恢复系数下降了0.23%。

Abstract:

To study radial cooling channel length changing impact on a new cross-flow type air cooled flameholder in cold flow field， based on the work condition in afterburner， using Navier-Stokes equations the 3D fluid-solid coupling heat transfer models of five air cooled flameholders with different radial cooling channel length were simulated. The external flow field of air cooled flameholder， the cooling efficiency of the outer wall surface of the radial flameholder， the thermal mixing efficiency and the total pressure recovery coefficient of the afterburner changing law were obtained. Within the range of parameter in this study， results indicate that the increase of the radial cooling channel length firstly enhances the turbulence mixing after the air cooled flameholder， so that the maximum of turbulent kinectic energy in the recirculation zone increases by 24.3%， and secondly weakens the cooling effect of the outer wall surface of the radial flameholder near the inner cone， resulting in the average cooling effect decreases of 14.4% on the radial flameholder’s windward side. Due to the increase of the radial cooling channel， thermal mix efficiency distribution curve along the afterburner moves upward， total pressure recovery coefficient distribution curve along the afterburner moves downward， and total pressure recovery coefficient at outlet of afterburner decreases by 0.23%.