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为研究超声速气流中液滴与气流的混合及液滴蒸发对混合的影响,采用大涡模拟(LES)方法数值仿真了超声速混合层内液滴两相流流场结构,气相流场采用亚格子(SGS)模型和切应力输运(k-ωSST)湍流模型,液相模拟采用轨道模型和单液滴蒸发模型。在混合层前缘入口处均匀持续地投放液滴,并在液滴入口处下方添加非周期小扰动,并观察液滴蒸发过程对该小扰动造成的影响。分析了入口小扰动在流场中不同的发展情况,发现液滴的蒸发过程使混合层厚度增加并加速混合层的发展,对气相流场扰动较强,可能导致流动失稳,对混合过程有很大的促进作用。
In order to study the influence of the mixture of droplet and gas flow and the droplet evaporation on the mixing in supersonic airflow, the flow field structure of droplets in supersonic mixed layer was numerically simulated by LES method. (SGS) model and shear stress transport (k-ωSST) turbulence model, liquid-phase simulation using orbit model and single-droplet evaporation model. Droplets were uniformly and continuously delivered at the inlet of the mixing layer leading edge and a small non-periodic disturbance was added below the drop entrance, and the effect of droplet evaporation on the small disturbance was observed. The different development of small disturbance in the flow field is analyzed. It is found that the evaporation process of the droplet increases the thickness of the mixed layer and accelerates the development of the mixed layer. The disturbances to the gas flow field are strong, which may cause the flow instability. For the mixing process Great role in promoting.