Single droplet deformation in pulsatile shear flow is numerically studied by using meso-scopic dissipative particle dynamics method. Numerical model and simulation method are fully validated with three typical cases in which transient flow behaviors are well captured. Cases in quasi-Stokes regime are first investigated with flow Reynolds number to be less than $O\left(10^{-2}\right)$. In early stage, droplet deforms gradually in the manner of periodic oscillation but irreversible. Later, droplet deformation gets into a stable state of oscillation and becomes reversible. The mean deformation parameter in stable state is frequency independent and its relationship to mean Capillary number is close to the trend in steady shear. Cases with finite inertia are studied with flow Reynolds number to be approximately to 1. In contrast, the inertial effects make the mean deformation parameters have a strong frequency dependence. The shear and relax tests are conducted to explain above dynamic behavior of droplet deformation. It is found that the droplet deformations in shear and relax are antisymmetric in quasi-Stokes regime while in finite inertia regime droplet deforms slower in shear process than it is in relax process. The frequency dependent behavior of droplet in pulsatile shear might provide a reliable strategy in the control of droplet deformation.

利用细观耗散粒子动力学方法对脉动剪切流中的单滴变形进行了数值研究。数值模型和仿真方法在三种典型情况下得到了充分验证，其中可以很好地捕获瞬态流动行为。首先研究准斯托克斯政权案件中的流雷诺数小于$Ø（\mathrm{1个}{0}^{-2}）$。在早期，液滴以周期性振荡的方式逐渐变形，但不可逆。之后，液滴变形进入稳定的振荡状态并变为可逆的。稳态下的平均变形参数与频率无关，它与平均毛细管数的关系接近稳态剪切的趋势。研究了具有有限惯性的情况，其中流雷诺数近似为1。相反，惯性效应使平均变形参数具有很强的频率依赖性。在剪切和放松进行测试以解释上述液滴变形的动态行为。发现在准斯托克斯状态下，剪切和松弛中的液滴变形是不对称的，而在有限惯性状态下，液滴在剪切过程中的变形比在松弛过程中的变形慢。液滴在脉动剪切中的频率相关行为可能为控制液滴变形提供可靠的策略。