Akbari Omid Ali, Shirani Ebrahim, Saghafian Mohsen
Mechanical Engineering Group, Pardis College, Isfahan University of Technology, Isfahan, 84156-83111, Iran.
Department of Mechanical Engineering, Isfahan University of Technology, Isfahan, 84156-83111, Iran.
Heliyon. 2024 Jan 6;10(2):e24065. doi: 10.1016/j.heliyon.2024.e24065. eCollection 2024 Jan 30.
This article, examines the flow of argon inside a nanochannel with respect to the molecular dynamics (MD) in the free molecular flow regime using LAMMPS software. The nanochannel is made of copper featuring a square cross-section and obstacles of varying dimensions and values. In this study, the flow of argon fluid is three-dimensional. To gain a deeper understanding of the effect of solid walls within the nanochannel and their influence on flow behavior, the research is simulated in a nanochannel with all side walls for the 3D model and without side walls for the 2D model. This research assesses the effect of the obstacles' dimensions and values on the nanochannel wall surface and areas above the wall surface. The total dimensions of all simulated two- and three-dimensional atomic structures with a square cross-section are assumed to be 60 × 60 × 100 Å. and the presence of square obstacles (with dimensions of 8 × 8 × 8 Å) and rectangular obstacles (with dimensions of 8 × 18 × 8 Å) is examined. This study seeks to understand the influence on flow behavior, temperature distribution, density, heat flux, velocity, and thermal conductivity coefficient. This study is simulated using a time step of 1 fs for 10,000 time steps, involving approximately 10,000-15,000 argon and copper atoms. The results of this research indicate that obstacles with structures of P and R and larger dimensions increase the number of solid atoms exhibiting stronger attractive forces. Compared to a smooth nanochannel, the thermal exchange between fluid and solid atoms results in a density increase of 17.5 % and 17.3 %, respectively. On the other hand, in the 3D nanochannel, the sidewalls of the nanochannel have reduced the effect of the presence of R and P obstacles with larger dimensions, which comparing to a smooth nanochannel, have increased the density by 8.21 % and 7.53 %, respectively. The obstacles with different spatial positions (P and R structures) in the two-dimensional nanochannel cause a rise in the thermal conductivity coefficient. The P structure obstacles have a better effect on the thermal conductivity coefficient in the 2D nanochannel compared to the R structure. In the three-dimensional nanochannel, utilizing smaller obstacles proves to be more effective because it results in better atom distribution or temperature distribution due to increased atomic collisions in the central region compared to the wall regions.
本文使用LAMMPS软件，研究了在自由分子流区域内纳米通道中氩气的流动与分子动力学（MD）的关系。该纳米通道由铜制成，具有方形横截面以及不同尺寸和数值的障碍物。在本研究中，氩流体的流动是三维的。为了更深入地了解纳米通道内固体壁的影响及其对流动行为的作用，研究在3D模型的有所有侧壁的纳米通道和2D模型的无侧壁的纳米通道中进行模拟。本研究评估了障碍物尺寸和数值对纳米通道壁表面以及壁表面上方区域的影响。所有模拟的方形横截面二维和三维原子结构的总尺寸假定为60×60×100Å，并研究了方形障碍物（尺寸为8×8×8Å）和矩形障碍物（尺寸为8×18×8Å）的存在情况。本研究旨在了解对流动行为、温度分布、密度、热通量、速度和热导率系数的影响。本研究使用1飞秒的时间步长进行10000个时间步的模拟，涉及大约10000 - 15000个氩原子和铜原子。本研究结果表明，具有P和R结构且尺寸较大的障碍物会增加表现出更强吸引力的固体原子数量。与光滑纳米通道相比，流体与固体原子之间的热交换分别导致密度增加17.5%和17.3%。另一方面，在三维纳米通道中，纳米通道的侧壁降低了尺寸较大的R和P障碍物的影响，与光滑纳米通道相比，其密度分别增加了8.21%和7.53%。二维纳米通道中具有不同空间位置（P和R结构）的障碍物会导致热导率系数升高。在二维纳米通道中，P结构障碍物对热导率系数的影响比R结构更好。在三维纳米通道中，使用较小的障碍物被证明更有效，因为与壁区域相比，它由于中心区域原子碰撞增加而导致更好的原子分布或温度分布。
