气动斜坡/燃气发生器方案燃料掺混性能研究

Research of Fuel Mixing Performance for Aerodynamic Ramp Injector

为了研究气动斜坡喷注器在提高掺混、点火及稳定火焰方面的作用,通过数值仿真方法,对气动斜坡及单孔直喷/燃气发生器2种方案冷流掺混流场进行了对比研究。结果表明:气动斜坡方案在燃烧室中能形成更强、更复杂的流向涡结构,对增进燃料掺混作用明显;在燃烧室后半段2种方案羽流面积相差不大,但是气动斜坡方案燃料质量中心在燃烧室中心区域附近,直喷方案燃料质量中心更靠近燃烧室上壁面,气动斜坡方案燃料分布更加均匀,到燃烧室出口处,掺混效率比直喷方案的高约10%;与直喷方案相比,气动斜坡方案对主流的影响更小,总压恢复性能优于直喷方案的,在燃烧室出口处,总压恢复系数比直喷方案的高约10%。

In order to study the effects of aerodynamic ramp injectors on the mixing enhancement, fuel ignition and flameholding, the non-reacting flow field of the aerodynamic ramp configuration was compared with that of the transverse injector configuration. The results show that the aerodynamic ramp induces a more intense streamwise vortex structure, which obviously enhances the fuel mixing efficiency. These two configurations have little difference on the flume area in the bottom half of the combustor. In the aerodynamic ramp configuration, the fuel is concentrated around the combustor central region, resulting in a more uniform fuel distribution. In the transverse injector configuration, the fuel is concentrated near the combustor top wall. At the combustor exit, the mixing efficiency of the a ynamic ramp configuration is approximately higher by 10% than that of the transverse injector configuration. Furthermore, due to fewer disturbances on the main flow, the aerodynamic ramp configuration provides a higher total pressure recovery by 10% than that of the second, at the combustor exit.