Related Experiment Video
Updated: Nov 17, 2025
06:37
Analyzing Melts and Fluids from Ab Initio Molecular Dynamics Simulations with the UMD Package
Published on: September 17, 2021
4.8K
SGTPy: A Python Code for Calculating the Interfacial Properties of Fluids Based on the Square Gradient Theory Using
Andrés Mejía1, Erich A Müller2, Gustavo Chaparro Maldonado1
1Departamento de Ingeniería Química, Universidad de Concepción, Concepción 4030000, Chile.
Journal of Chemical Information and Modeling
|February 17, 2021
Summary
This study introduces SGTPy, an open-source Python code for calculating fluid interfacial properties using Square Gradient Theory (SGT) and SAFT-VR-Mie. SGTPy enables phase stability, equilibria calculations, and interfacial property computations for diverse fluid systems.
Area of Science:
- Thermodynamics and physical chemistry.
- Computational fluid dynamics and molecular modeling.
Background:
- Calculating interfacial properties is crucial for understanding fluid behavior.
- Existing methods may lack flexibility or ease of use for complex fluid mixtures.
Purpose of the Study:
- To present SGTPy, a novel open-source Python code for interfacial property calculations.
- To couple Square Gradient Theory (SGT) with the Statistical Associating Fluid Theory of Variable Range (SAFT-VR-Mie) for enhanced accuracy.
Main Methods:
- Development of SGTPy using standard Python numerical packages (NumPy, SciPy).
- Implementation of SGT coupled with SAFT-VR-Mie equation of state.
- Inclusion of multiple techniques for solving interfacial concentration, such as path technique and orthogonal collocation.
- Facilitation of integration with Fortran and C++ subroutines via Cython and f2py.
Main Results:
- SGTPy successfully calculates interfacial concentration profiles and surface tension for pure fluids and mixtures.
- The code handles phase stability, phase equilibria (including multiphase flash, bubble/dew points), and parameter optimization.
- Demonstrated capabilities through Jupyter notebooks with examples for pure and multicomponent systems.
Conclusions:
- SGTPy provides a versatile and extensible platform for interfacial property calculations.
- The open-source nature and integration capabilities of SGTPy promote further research and application in fluid thermodynamics.
More Related Videos
Related Concept Videos
01:22Surface Tension of Fluid
872
Surface tension is a fundamental property of fluids, occurring at the boundary between a liquid and a gas or between two immiscible liquids. This phenomenon arises from the cohesive forces between molecules at the fluid's surface, creating an effect similar to a stretched elastic membrane. Inside each fluid, molecules are equally attracted in all directions by neighboring molecules, but surface molecules experience a net inward force, resulting in surface tension.
Surface tension varies...
Surface tension varies...
872
01:17Accelerating Fluids
1.8K
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:
1.8K
01:18Newtonian Fluid: Problem Solving
652
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...
652
01:28Vapor Pressure of Fluid
1.6K
The vapor pressure of a fluid is a crucial concept in fluid mechanics, influencing phenomena such as boiling and cavitation. Vapor pressure refers to the pressure exerted by a vapor at a state of thermodynamic equilibrium with its corresponding liquid phase at a specific temperature. It represents the tendency of molecules to escape from the fluid surface into the vapor phase.
When a liquid is placed in a closed container with a small air space, and the space is evacuated, vapor molecules will...
When a liquid is placed in a closed container with a small air space, and the space is evacuated, vapor molecules will...
1.6K
01:19Viscosity of Fluid
907
Viscosity measures the resistance a fluid offers to flow and deformation. It results from internal friction between layers of fluid moving relative to one another. Dynamic viscosity, denoted by the Greek letter mu (μ), quantifies the force needed to move one fluid layer over another. For Newtonian fluids like water and air, the relationship between the shearing stress and the rate of shearing strain is linear, meaning their viscosity remains constant regardless of the applied stress.
907
01:14Pressure of Fluids
18.7K
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...
18.7K