Thermal lattice Boltzmann method for complex microflows

Area of Science:

• Computational fluid dynamics
• Microfluidics
• Heat transfer

Background:

• Simulating thermal fields in microflow geometries presents challenges.
• Accurate boundary conditions are critical for microfluidic thermal simulations.

Purpose of the Study:

• To propose a novel methodology for simulating thermal fields in complex microflow geometries.
• To validate the proposed simulation scheme against established benchmarks.

Main Methods:

• Utilized the regularized multiple-relaxation-time lattice Boltzmann method (LBM) for flow fields.
• Employed the regularized lattice Bhatnagar-Gross-Krook model for thermal fields.
• Developed and applied a mixed diffuse scattering and constant temperature boundary condition for thermal walls.

Main Results:

• The regularization of thermal LBM is essential to prevent kinked temperature profiles.
• The new thermal wall boundary condition accurately captures thermal jumps at walls.
• Validation against Fourier and square cylinder flows confirmed the method's accuracy.

Conclusions:

• The proposed LBM-based methodology accurately simulates thermal fields in complex microflows.
• Regularization is vital for achieving accurate temperature profiles in microfluidic heat transfer.
• The novel thermal wall boundary condition enhances the precision of microfluidic simulations.