本项目拟将多体耗散粒子动力学与能量守恒耗散粒子动力学相结合，针对介观尺度热毛细现象进行数值模拟研究。建立DPD系统关键参数与温度之间的依赖关系，有效反映液气、液固与气固界面张力；将系统的粗粒化尺度与热波动程度相联系，体现不同粗粒化尺度下不同热波动程度所起的作用；研究不同液滴尺寸条件下浮升力对流与热毛细对流共同作用对液滴内部复杂流场的影响，并与实验进行对照；研究具有温度梯度表面上液滴的热毛细迁移，阐述液滴的运动规律。研究微粗糙结构表面上粗糙形貌、浸润性、接触角滞后性对于液滴热毛细驱动的影响规律；探索液滴热毛细迁移过程中能量的耗散机制，解析液滴的“粘滞-滑移”行为；模拟亚微米尺度上液滴射流颈缩过程；研究在喷嘴部位液滴接触线附近温度梯度对于液滴生成过程的重要影响，以及不同形式的脉冲加热和非轴对称加热对液滴生成的影响。本项目拟为表面科学机理研究、微流体器件的研发等提供见解。

Mesoscopic simulation of droplet thermocapillary phenomena will be carried out by combining multi-body dissipative particle dynamics and energy conservative dissipative particle dynamics. The relation between DPD parameters and temperature will be established, by which the liquid-vapor, liquid-solid and vapor-solid interfacial tension could be computed. Furthermore, the thermal fluctuations will be considered depending on the scale at which the model is operating, so as to reflect the effect of the level of coarse-graining on the thermal fluctuations. The effect of combined thermocapollary-bouyancy convection on the flow field inside the droplet with various sizes will be investigated, and it will be compared by experimental results. The thermocapillary migration of an attached drop on a solid surface with a temperature gradient will be simulated, in which the motion velocity of the droplet will be analyzed. The effect of topographies, wetting properties and contact angle hysteresis on drop thermocapillary migration will be discussed. The energy dissipation mechanism of droplet motion will be assessed, by which the "stick-slip" behavior of the droplet will be analyzed. The thinning and breakup of liquid jet at submicron level will be simulated. The effect of the temperature gradient between the vicinity of the contact line and the rest of the droplet on the formation of droplets will be investigated, and different kinds of pulse heating and asymmetrically heating at the nozzle will be analyzed. The proposal, by supplying with detailed mesoscopic DPD simulation information, will be aimed at understanding the fundamentals in terms of interface science research, development of MEMS devices etc.