为了考察液滴的撞击对液膜变形行为的影响规律,利用CLSVOF(coupled level set and volume of fluid)方法模拟双液滴同时撞击平面液膜后的流动过程,获得了不同水平间隔距离、不同撞击速度的两液滴撞击平面液膜后的演变过程特点,通过分析...为了考察液滴的撞击对液膜变形行为的影响规律,利用CLSVOF(coupled level set and volume of fluid)方法模拟双液滴同时撞击平面液膜后的流动过程,获得了不同水平间隔距离、不同撞击速度的两液滴撞击平面液膜后的演变过程特点,通过分析不同时刻压力场分布,探索了两液滴水平间隔距离、韦伯数和撞击速度对双液滴同时撞击液膜后流动过程、形态及对水花高度和中心射流高度的影响。结果表明,碰撞速度较大时的中心液膜射流高度大于碰撞速度较小时的;We数较大时中心射流顶端将产生二次液滴;液滴间距对撞击后初始时(3 ms之前)撞击点两侧的开始水花高度没有明显影响。展开更多
Molecular dynamics(MD)simulations are employed to delve into the multifaceted effects of TiB_(2) nanoparticles on the intricate grain refinement mechanism,microstructural evolution,and tensile performance of Inconel 7...Molecular dynamics(MD)simulations are employed to delve into the multifaceted effects of TiB_(2) nanoparticles on the intricate grain refinement mechanism,microstructural evolution,and tensile performance of Inconel 718 superalloys during the rapid directional solidification.Specifically,the study focuses on elucidating the role of TiB2 nanoparticles in augmenting the nucleation rate during the rapid directional solidification process of Ni_(60)Cr_(21)Fe_(19) alloy system.Furthermore,subsequent tensile simulations are conducted to comprehensively evaluate the anisotropic behavior of tensile properties within the solidified microstructures.The MD results reveal that the incorporation of TiB₂nanoparticles during the rapid directional solidification of the Ni_(60)Cr_(21)Fe_(19) significantly enhances the average nucleation rate,escalating it from 1.27×10^(34)m^(-3)·s^(-1)to 2.55×10^(34)m^(-3)·s^(-1).Notably,within the face centered cube(FCC)structure,Ni atoms exhibit pronounced compositional segregation,and the solidified alloy maintains an exceptionally high dislocation density reaching up to 10^(16)m^(-2).Crucially,the rapid directional solidification process imparts a distinct microstructural anisotropy,leading to a notable disparity in tensile strength.Specifically,the tensile strength along the solidification direction is markedly superior to that perpendicular to it.This disparity arises from different deformation mechanisms under varying loading orientations.Tensile stress perpendicular to the solidification direction encourages the formation of smooth and organized mechanical twins.These twins act as slip planes,enhancing dislocation mobility and thereby improving stress relaxation and dispersion.Moreover,the results underscore the profound strengthening effect of TiB_(2) nanoparticles,particularly in enhancing the tensile strength along the rapid directional solidification direction.展开更多
文摘为了考察液滴的撞击对液膜变形行为的影响规律,利用CLSVOF(coupled level set and volume of fluid)方法模拟双液滴同时撞击平面液膜后的流动过程,获得了不同水平间隔距离、不同撞击速度的两液滴撞击平面液膜后的演变过程特点,通过分析不同时刻压力场分布,探索了两液滴水平间隔距离、韦伯数和撞击速度对双液滴同时撞击液膜后流动过程、形态及对水花高度和中心射流高度的影响。结果表明,碰撞速度较大时的中心液膜射流高度大于碰撞速度较小时的;We数较大时中心射流顶端将产生二次液滴;液滴间距对撞击后初始时(3 ms之前)撞击点两侧的开始水花高度没有明显影响。
基金supported by the Na⁃tional Natural Science Foundation of China(Nos.12462006,12062016)the high-performance computing services of⁃fered by the Information Center of Nanchang Hangkong Uni⁃versity.
文摘Molecular dynamics(MD)simulations are employed to delve into the multifaceted effects of TiB_(2) nanoparticles on the intricate grain refinement mechanism,microstructural evolution,and tensile performance of Inconel 718 superalloys during the rapid directional solidification.Specifically,the study focuses on elucidating the role of TiB2 nanoparticles in augmenting the nucleation rate during the rapid directional solidification process of Ni_(60)Cr_(21)Fe_(19) alloy system.Furthermore,subsequent tensile simulations are conducted to comprehensively evaluate the anisotropic behavior of tensile properties within the solidified microstructures.The MD results reveal that the incorporation of TiB₂nanoparticles during the rapid directional solidification of the Ni_(60)Cr_(21)Fe_(19) significantly enhances the average nucleation rate,escalating it from 1.27×10^(34)m^(-3)·s^(-1)to 2.55×10^(34)m^(-3)·s^(-1).Notably,within the face centered cube(FCC)structure,Ni atoms exhibit pronounced compositional segregation,and the solidified alloy maintains an exceptionally high dislocation density reaching up to 10^(16)m^(-2).Crucially,the rapid directional solidification process imparts a distinct microstructural anisotropy,leading to a notable disparity in tensile strength.Specifically,the tensile strength along the solidification direction is markedly superior to that perpendicular to it.This disparity arises from different deformation mechanisms under varying loading orientations.Tensile stress perpendicular to the solidification direction encourages the formation of smooth and organized mechanical twins.These twins act as slip planes,enhancing dislocation mobility and thereby improving stress relaxation and dispersion.Moreover,the results underscore the profound strengthening effect of TiB_(2) nanoparticles,particularly in enhancing the tensile strength along the rapid directional solidification direction.
