Yusuke Kuwata

Turbulence over/inside porous surfaces and challenges to its modelling

To understand turbulence over porous media, a series of PIV measurements were carried out in porous-wall channel flows. The porous walls were made of three types of foamed ceramics which had the same porosity but different permeability. For turbulence inside porous media, LES studies of fully developed flows in several model porous media were performed. Referring to these databases, a multi-scale κ–e four equation eddy viscosity model for turbulence around/inside porous media was developed. The proposed model was validated with satisfactory accuracy.

Lattice Boltzmann Method for Turbulent Flows

An accurate and robust lattice Boltzmann method for calculating turbulent flows by direct and large eddy simulation is developed. For the discrete velocity model, the D3Q27 model is proven to be desirable for turbulent flow simulation and then a multiple relaxation time (MRT) form is derived. To avoid unphysical kinks in turbulent quantities at grid interfaces by local mesh refinement, a correction method is developed. Coupling this imbalance correction (IBC) mesh refinement method with the D3Q27 MRT LBM, large scale turbulence simulation is effectively performed.