Related Experiment Video
Updated: Aug 16, 2025
11:03
An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids
Published on: December 4, 2017
8.6K
Simulation of a Particle Domain in a Continuum, Fluctuating Hydrodynamics Reservoir
Abbas Gholami1, Rupert Klein1, Luigi Delle Site1
1Freie Universität Berlin, Institute of Mathematics, Arnimallee 6, 14195 Berlin, Germany.
Physical Review Letters
|December 23, 2022
Summary
This study introduces a new adaptive resolution scheme (AdResS) coupled with fluctuating hydrodynamics (FHD) for molecular simulations. This method enables physically consistent simulations of complex molecular systems, including thermal fluctuations.
Area of Science:
- Molecular Simulation
- Fluid Mechanics
- Computational Physics
Background:
- Coupling particle-based molecular dynamics with continuum fluid mechanics is a significant challenge.
- Existing methods struggle to consistently model the interplay between discrete and continuous phases.
Purpose of the Study:
- To develop a novel, physically consistent algorithm for multiscale simulations.
- To enable accurate modeling of both density and thermal fluctuations in complex systems.
Main Methods:
- Integration of the adaptive resolution scheme (AdResS) with a fluctuating hydrodynamics (FHD) solver.
- Utilizing noninteracting tracers as a particle reservoir within the AdResS framework.
- Development of a robust mathematical model for inter-domain exchange.
Main Results:
- Demonstrated a physically consistent exchange of matter and energy between particle and continuum domains.
- Validated the algorithm's accuracy through numerical tests.
- Enabled simulations that capture both density and thermal fluctuations.
Conclusions:
- The novel AdResS-FHD algorithm provides a powerful tool for simulating large, complex molecular systems.
- This approach significantly advances the capability to model systems like hydrated biological membranes in thermal fields.
- The method offers efficient treatment of multiscale phenomena with coupled particle and continuum behaviors.
Related Concept Videos
01:30Typical Model Studies
417
Fluid mechanics model studies often utilize scaled-down systems to predict fluid behavior in full-scale environments, such as river flows, dam spillways, and structures interacting with open surfaces. Maintaining Froude number similarity in river models is crucial, as it replicates surface flow features like wave patterns and velocities.
417
01:17Accelerating Fluids
1.1K
When a fluid is in constant acceleration, the pressure and buoyant force equations are modified. Suppose a beaker is placed in an elevator accelerating upward with a constant acceleration, a. In the beaker, assume there is a thin cylinder of height h with an infinitesimal cross-sectional area, ΔS.
The motion of the liquid within this infinitesimal cylinder is considered to obtain the pressure difference. Three vertical forces act on this liquid:
The motion of the liquid within this infinitesimal cylinder is considered to obtain the pressure difference. Three vertical forces act on this liquid:
1.1K
01:11Pressure Variation in a Fluid at Rest
336
In a fluid at rest, the pressure at any point beneath the fluid surface depends solely on the depth, not on the container's shape or size. This principle, known as hydrostatic pressure, arises because, in stationary fluids, there is no acceleration, meaning the forces within the fluid balance out. Only vertical forces, caused by the weight of the fluid above, contribute to pressure changes with depth.
When measuring pressure at two different levels within the fluid, the difference in...
When measuring pressure at two different levels within the fluid, the difference in...
336
01:18Newtonian Fluid: Problem Solving
323
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...
323
01:12Fluid Pressure over Curved Plate of Constant Width
1.6K
When a curved plate of constant width is submerged in a liquid, the pressure acting normal to the plate varies continuously both in magnitude and direction. Calculating the magnitude and location of the resultant force at a point is often challenging for such cases. One of the methods to determine the resultant force and its location involves separately calculating the horizontal and vertical components of the resultant force. This complex calculation can be simplified by representing the...
1.6K
01:14Pressure of Fluids
16.5K
There are many examples of pressure in fluids in everyday life, such as in relation to blood (high or low blood pressure) and in relation to weather (high- and low-pressure weather systems). A given force can have a significantly different effect, depending on the area over which the force is exerted. For instance, a force applied to an area of 1 mm2 has a pressure that is 100 times greater than the same force applied to an area of 1 cm2. That's why a sharp needle is able to poke through...
16.5K