Density gradient calculation in a class of multiphase lattice Boltzmann models.

Area of Science:

• Computational fluid dynamics
• Multiphase flow simulation
• Lattice Boltzmann methods

Background:

• Multiphase lattice Boltzmann (LB) models using pairwise interactions offer computational simplicity for simulating complex fluid dynamics.
• These models implicitly involve density gradients through specialized forcing or consistent schemes, crucial for accurate multiphase flow dynamics.

Purpose of the Study:

• To analyze and improve the calculation of density gradients in pairwise interaction-based multiphase LB models.
• To develop a more accurate method for density gradient computation, especially for LB models with self-tuning equations of state.

Main Methods:

• Theoretical analysis of density gradient involvement in multiphase LB models.
• Development of an improved density gradient calculation scheme based on low Mach number approximation.
• Analytical and numerical validation of the proposed scheme.

Main Results:

• The study reveals the implicit role and calculation methods of density gradients in multiphase LB models.
• An improved scheme for density gradient calculation is proposed and validated.
• The enhanced scheme demonstrates increased accuracy and reduced numerical errors, particularly at low reduced temperatures.

Conclusions:

• The proposed improved scheme enhances the accuracy of density gradient calculations in multiphase LB models.
• This advancement contributes to more reliable simulations of multiphase flows, especially under low-temperature conditions.
• The findings are significant for computational fluid dynamics research utilizing LB methods.