使用混合粒子场分子动力学模拟的粘度计算
Simon A N Alberti1, Evangelia Charvati1, Giuseppe Milano2
1Eduard-Zintl-Institute of Inorganic and Physical Chemistry, Technical University of Darmstadt, Peter-Grünberg-Straße 8, D-64287 Darmstadt, Germany.
The journal of physical chemistry. B
|August 5, 2025
概括
混合粒子场分子动力学 (MD) 与多粒子碰撞动力学 (MPCD) 准确模拟流体粘度. 这种HPF-MPCD方法提供了显著的计算加速度,并优于复杂流体系统的传统MD.
科学领域:
- 计算物理学的计算物理.
- 流体动力学 流体动力学
- 分子动力学模拟的模拟.
背景情况:
- 混合粒子场 (HPF) 分子动力学 (MD) 模拟可以在不平衡的剪切流中展示文物,因为没有明确的粒子碰撞.
- 这些工件导致非线性速度配置文件,限制了传统HPF方法的准确性.
研究的目的:
- 通过整合多粒子碰撞动态 (MPCD) 来解决HPF模拟的局限性.
- 准确计算流体粘度,并研究合并HPF-MPCD方法的性能.
主要方法:
- 混合粒子场 (HPF) 分子动力学模拟与多粒子碰撞动力学 (MPCD) 结合.
- 进行了切割流的非平衡MD模拟,以分析速度概况和粘度.
- 调整了MPCD碰撞周期 (Tcol),以调整流体粘度.
- 使用8点中心差梯度插曲分析了动量保存.
主要成果:
- 将MPCD集成到HPF中成功模拟了碰撞动态,产生了与伦纳德-斯 (LJ) 模拟相美的线性速度概况.
- 导出了粘度 (η(ρ,T)) 的一般方程,显示HPF-MPCD系统与LJ流体相比对温度和密度的依赖性较弱.
- HPF和HPF-MPCD方法展示了显著的计算效率,比传统的MD更快的模拟速度高达3个数量级.
- 八点中心差梯度插值方法在动量保存的准确性和稳定性方面证明是优越的.
结论:
- 该HPF-MPCD方法准确计算流体粘度,并克服了标准HPF模拟中存在的工件.
- 这种方法为模拟复杂的流体系统提供了一个可扩展,多功能和计算效率高的替代传统的MD.
- 这些发现突显了HPF-MPCD在流体动力学的大规模,高采样模拟中的潜力.
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