Lattice Boltzmann simulation of thermal nonideal fluids

Area of Science:

• Thermodynamics
• Fluid Dynamics
• Computational Physics

Background:

• Phase separation is crucial in fluid dynamics.
• Understanding thermal effects in phase separation is complex.
• Previous models lacked detailed thermal dynamics.

Purpose of the Study:

• To propose a thermal lattice Boltzmann model for van der Waals fluids.
• To analyze phase separation dynamics under thermal influence.
• To validate the model against existing continuum theories.

Main Methods:

• Developed a thermal lattice Boltzmann model.
• Simulated a van der Waals fluid system quenched by external walls.
• Analyzed system thermalization and phase separation using the model.

Main Results:

• The model reproduces second-order Chapman-Enskog expansion results.
• Pressure waves rapidly thermalize the bulk fluid.
• Homogeneous bulk temperature is achieved before phase separation completes.
• Transient liquid-vapor layers form at the walls.

Conclusions:

• The proposed model accurately captures thermal effects during phase separation.
• The study highlights the role of pressure waves in rapid thermalization.
• The findings provide insights into fluid behavior near boundaries during phase transitions.