低频压力振荡环境下运动液滴蒸发过程的准稳态模型

Quasi-steady model of moving droplet evaporation process under low frequency pressure oscillation

为了获得运动液滴蒸发过程对压力震荡的响应特性,从宏观上对压力振荡环境下的液滴蒸发过程进行了分析,压力振荡会引起液滴周围边界层内蒸汽质量分数的振荡,从而引起液滴蒸发速率的振荡。根据折算薄膜理论,提出了折算饱和蒸汽边界层的概念,基于已有的液滴蒸发准稳态模型,建立了压力振荡环境下运动液滴蒸发过程的准稳态模型,并进行数值求解,结果表明,液滴蒸发过程对低频压力震荡具有很强的响应能力,尤其对压力震荡幅值、频率比较敏感。

In order to obtain the response characteristics of moving droplet evaporation process under low frequency pressure oscillation,the process of droplet evaporation under pressure oscillation is analyzed in a level of macroscopic view.It indicates that pressure oscillation can bring the oscillation of vapor mass fraction in the boundary layer around droplet,and induces the droplet evaporation rate oscillation.According to the converted film theory,a concept of the converted saturation vapor boundary layer is presented.The quasi-steady model of moving droplet evaporation process with pressure oscillation is constructed based on the existent quasi-steady model of droplet evaporation,and resolved numerically.The results show that moving droplet evaporation process has strong response ability to pressure oscillation,especially sensitive to pressure oscillation amplitude and frequency.