Home – Home – Jornals – Journal of Applied Mechanics and Technical Physics 2026 number 2

A pseudo-direct numerical simulation of turbulent natural convection in a closed, nonuniformly heated square cavity filled with air is performed. The velocity components are calculated using the lattice Boltzmann method with high-order regularization. Thermodynamic characteristics are analyzed by solving the macroscopic energy equation using a fourth-order Runge-Kutta finite-difference scheme. The developed hybrid algorithm, which mimics the direct numerical simulation approach, is tested on benchmark problems of turbulent natural convection. Numerical simulations are carried out over a Rayleigh number range of 10¹⁰ ≤ R ≤ 10¹¹. It is found that, as R increases, the intensity of thermal plume generation on the isothermal walls becomes greater and the region of turbulent vortex formation expands. Stagnation zones of the heat transfer fluid are identified near the horizontal walls. The distribution of second-order statistics, with the exception of temperature variance, is shown to depend on the thermal plume configuration.