在大小多分散硬球体流体中的刚性纤维的动力学
Thokchom Premkumar Meitei1, Lenin S Shagolsem1
1Department of Physics, National Institute of Technology Manipur, Imphal, India.
The Journal of chemical physics
|September 17, 2025
概括
研究复杂流体中的杆动力学揭示了大小多分散性显著影响旋转扩散. 增加多分散度 (δ) 在恒压下与恒体体积分数 (φ) 下不同地影响动力学.
科学领域:
- 软物质物理学 软物质物理学
- 复杂的流体复杂的流体.
- 计算物理学的计算物理.
背景情况:
- 在复杂的流体中解释实验结果是具有挑战性的,因为流体的多分散性和合棒运动.
- 体积分数 (φ) 和自由体积 (Vfree) 对多散系统动态的影响需要进一步研究.
研究的目的:
- 为了研究大小多散流体中棒状丝的动态.
- 要了解大小多分散性 (δ) 在恒压和恒体体积分数 (φ) 下对杆动态的影响.
主要方法:
- 使用了分子动力学模拟.
- 在柔软的排斥球体的流体中研究了杆动力学,这些球体具有不同程度的尺寸多分散性 (δ).
- 在两个条件下进行模拟:恒压和恒体体积分数 (φ).
主要成果:
- 在恒压下,旋转放松时间随着棒的长度 (l) 随着DR ∼ l-α的增加而增加,α从约3.0增加到3.2随着δ从0%增加到40%.
- 增加体积分数 (φ) 的效应在不断压力下增加自由体积 (Vfree) 时占主导地位.
- 在固定的φ系统中,增加的多分散性 (δ) 导致增加的自由体积 (Vfree),增强标记物扩散,与恒压条件相反.
结论:
- 尺寸多分散性在复杂流体中显著改变了杆动力学.
- 体积分数,自由体积和多分散性之间的相互作用决定了动态行为.
- 棒内部的水力动力学相互作用对旋转动力学影响很小,但选会影响质心运动.
相关概念视频
01:20Stokes' Law
2.6K
Viscous forces, like friction, are intermolecular forces that resist the relative motion of molecules over each other. When a solid body moves through a liquid, viscous forces drag it in the opposite direction. The force's magnitude depends on the solid's shape and size, as well as its speed and the liquid's coefficient of viscosity, density and temperature.
The expression for the force on a solid spherical object in a fluid is called Stokes' law. Stokes' law is valid only...
The expression for the force on a solid spherical object in a fluid is called Stokes' law. Stokes' law is valid only...
2.6K
01:20Characteristics of Fluids
7.8K
When a force is applied parallel to the top surface of a solid, it resists the applied force due to the internal frictional forces between the layers of the solid known as shearing resistance. However, when the force is removed, the shearing forces restore the original shape of the solid. Other deformation forces also cause temporary changes in shape if the forces are not beyond a threshold magnitude. Solids tend to retain their shape, making the study of their rest and motion easier. Beyond...
7.8K
01:23Steady, Laminar Flow in Circular Tubes
1.0K
Hagen-Poiseuille flow describes a viscous fluid's steady, incompressible flow through a cylindrical tube with a constant radius R. This flow profile is often applied to understand fluid transport in narrow channels, such as capillaries. It serves as a foundational example of laminar flow. In this model, cylindrical coordinates (r,θ,z) are used to describe the radial (r), angular (θ), and axial (z) dimensions within the tube. For Hagen-Poiseuille flow, the velocity profile is purely axial,...
1.0K
01:18Newtonian Fluid: Problem Solving
885
Newtonian fluids exhibit a constant viscosity, meaning their shear stress and shear strain rate are directly proportional. This property ensures a predictable and stable response to applied forces, maintaining a linear relationship between force and flow. Examples include water, air, and light oils, consistently demonstrating this proportional behavior regardless of external conditions.
A velocity gradient forms within the fluid when a Newtonian fluid is placed between two parallel plates, with...
A velocity gradient forms within the fluid when a Newtonian fluid is placed between two parallel plates, with...
885
01:08Molecular Weight of Step-Growth Polymers
2.7K
Step growth polymerization involves bi or multifunctional monomers. Bifunctional monomers react to form linear step growth polymers, whereas multifunctional monomers react to form non-linear or branched polymers.
As the step-growth polymerization involves step-wise condensation of monomers, the molecular weight also builds up eventually. Consequently, high molecular weight polymers are obtained at the late stages of the polymerization, where 99% of monomers have been consumed.
The extent of the...
As the step-growth polymerization involves step-wise condensation of monomers, the molecular weight also builds up eventually. Consequently, high molecular weight polymers are obtained at the late stages of the polymerization, where 99% of monomers have been consumed.
The extent of the...
2.7K
01:10Polymers: Molecular Weight Distribution
4.7K
For any given polymer, the weight average molecular weight (Mw) is higher than, if not equal to, the number average molecular weight (Mn). The only situation in which the weight average molecular weight and the number average molecular weight are equal is when a polymer consists only of chains with equal molecular weight. However, this never happens in a synthetic polymer, since it is difficult to control the polymerization process up to a molecular level with accuracy to a hundred percent.
4.7K