LATTICE BOLTZMANN AND SPECTRAL SIMULATIONS OF NONLINEAR STABILITY OF KOLMOGOROV FLOWS

Abstract

The non-linear stability of the Kolmogoroff flow is numerically studied using both spectral and lattice Boltzmann simulations with the aim of validating these latter techniques. Three different methods were applied: one standard spectral method and two types of lattice Boltzmann simulations. Results, in the farm of streamline and vorticity patterns, are presented for different Reynolds and wave numbers (aspect ratio), showing generally good agreement among the three techniques and with well known results in the literature. This agreement is better for steady or quasi-steady situations, and an explanation for this feature is provided.