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通过使用散射粒子动力学在中等尺度上以非线性运输系数建模的非牛顿动力学

Ali Naseri¹, Clara Salueña Perez², Josep Bonet Avalos¹

¹Departament d'Enginyeria Química, Universitat Rovira i Virgili, Tarragona, Spain. josep.bonet@urv.cat.

Physical chemistry chemical physics : PCCP

|December 4, 2024

概括

我们开发了新的消散粒子动力学 (DPD) 算法,以速度依赖的摩擦,实现宏观的剪切稀释行为. 我们的方法纠正了假效应,并简化了非线性摩擦的模拟.

科学领域:

计算物理计算物理
软物质物理学软物质物理学
类风病学类风病学类风病学

背景情况:

标准散射粒子动力学 (DPD) 模型通常使用线性摩擦系数.
模拟非线性质现象,如剪切稀释,需要先进的摩擦模型.
非线性摩擦和波动的合可以在DPD模拟中引入虚假的行为.

研究的目的:

导出DPD的算法与速度依赖的摩擦系数.
介绍一种新的粒子间摩擦模型,表现出剪切稀释行为.
开发一个强大的数值方法来模拟非线性DPD动态.

主要方法:

导出了DPD算法,其中包含了取决于速度的摩擦系数.
引入局部应变速率估计器来建模粒子间摩擦.
开发和应用非线性摩擦的波动分散定理.
数值验证包括麦克斯韦尔-博尔兹曼速度分布和与线性模型的比较.
实现了一种新的两步算法,用于集成DPD动态方程.

主要成果:

成功推导出DPD算法用于取决于速度的摩擦.
由拟议的粒子间摩擦模型产生的宏观剪切稀释行为.
验证了模型的一致性,并纠正了由非线性摩擦-波动合引起的虚假行为.
新的两步算法允许在没有明确导出校正项的情况下进行模拟.

结论:

开发的DPD模型准确地捕捉了剪切稀释现象.
新的算法和数值方法为模拟复杂的流体动力学提供了强大的框架.
两步集成算法为非线性DPD模拟提供了显著的方法进步.

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