中文摘要：

考虑表面张力、热传递和凝固,利用不可压SPH模型（ISPH）研究熔滴在固体表面碰撞后变形、展开、传热和凝固的过程。采用范德华力模型模拟微小粒子的表面张力,同时建立了基于傅里叶传热定律的热传递模型,并在求得SPH粒子的内能和温度后,根据内能与温度的关系判断SPH粒子是固态、熔化状态或完全熔化的液态。利用该模型研究了热喷涂过程中熔滴碰撞后变形、传热和凝固的过程,分析了熔滴的展开系数与基板的粗糙程度、倾斜角度等影响因素的关系。结果表明,随着基板倾斜角度增大,熔滴凝固后的展开系数显著增大;基板越粗糙,熔滴的展开系数越小。

英文摘要：

A meshfree numerical model based on the incompressible smoothed particle hydrodynamics（ISPH） is proposed for the process of droplet impact,transforming,spreading,heat-conducting and solidification on the substrate.Fourier＇s law holds for the heat conduction and van der Waals interaction is taken into account for the droplet surface tension.Droplet solidification is determined from the conservation of internal energy,and the solidification interface is predicted from the temperature distribution.This ISPH model is applied to the thermal-sprayed droplets on different substrates,i.e.,smooth or rough,perpendicular or inclined.The influence of roughness and incline angle on the flattening ratio is parametrically studied.Results show that the flattening ratio increases with the incline angle,and decreases as the substrate gets rougher.