Analysis of the pressure fluctuations from an LBM simulation of turbulent channel flow

The results from a simulation of turbulent channel flow computed using the D3Q19 athermal lattice Boltzmann method (LBM) are compared to those calculated using Navier–Stokes-based solvers. It is found that, when the computational domain of the simulation is made large enough, the magnitude of the LBM’s overprediction of the pressure fluctuations in the near-wall region is on the order of that expected from compressibility effects. However, the relationship between density, temperature, and pressure in the LBM is different from that found in a fully-compressible simulation. For this reason, it is recommended that the athermal LBM should not be used for simulations in which the density and temperature fluctuations may play an important role.

► The D3Q19 LBM is rigorously validated for wall-bounded turbulent flow.
► The LBM was compared with an incompressible Navier–Stokes-based method.
► The difference in the pressure fluctuations was found to be caused by compressibility.
► The LBM pressure fluctuations compare better with a compressible simulation.
► The D3Q19 LBM should not be used when density and temperature fluctuations are important.