Both methods are powerful CFD solvers, but they use different approaches and have different benefits. Navier-Stokes methods treat the fluid as a continuum, while Lattice Boltzmann method treats it as discrete particles.
To solve the Navier-Stokes equations computationally, the physical space to be simulated is divided into many small subdomains called control volumes or cells. The equations are discretized across the cells, and the resulting set of algebraic equations is solved iteratively to obtain the pressure, velocity, temperature (and other physical quantities) in each cell for steady or unsteady flows. Additional discretized transport equations can be solved in the same way to represent other physical phenomena like turbulence and chemical species.
The Lattice Boltzmann method of CFD simulation tracks the microscopic motion of fluid particles through discrete space and time, to simulate the flow of gases and liquids. The fluid space is automatically discretized into cubic voxels, and boundaries into surfels, eliminating the need for conventional surface and volume grid generation. The Very Large Eddy Scale (VLES) turbulence modeling approach ensures that anisotropic fluid structures are captured with high fidelity, which is critical for aerodynamics and aeroacoustics workflows.