Related Experiment Video
Updated: Mar 22, 2026

An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids
Published on: December 4, 2017
Molecular Hydrodynamics from Memory Kernels
Dominika Lesnicki1, Rodolphe Vuilleumier1, Antoine Carof2
1École Normale Supérieure, PSL Research University, Département de Chimie, Sorbonne Universités-UPMC Université Paris 06, CNRS UMR 8640 PASTEUR, 24 rue Lhomond, 75005 Paris, France.
Abstract:
The memory kernel for a tagged particle in a fluid, computed from molecular dynamics simulations, decays algebraically as t^{-3/2}. We show how the hydrodynamic Basset-Boussinesq force naturally emerges from this long-time tail and generalize the concept of hydrodynamic added mass. This mass term is negative in the present case of a molecular solute, which is at odds with incompressible hydrodynamics predictions. Lastly, we discuss the various contributions to the friction, the associated time scales, and the crossover between the molecular and hydrodynamic regimes upon increasing the solute radius.
More Related Videos
Related Concept Videos
Accelerating Fluids
The motion of the liquid within this infinitesimal cylinder is considered to obtain the pressure difference. Three vertical forces act on this liquid:
Distribution of Molecular Speeds
The Fluid Mosaic Model
Fluid Mosaic Model
Molecular Comparison of Gases, Liquids, and Solids
Molecular Kinetic Energy

