Abstract
A large-eddy simulation of a buoyant plume past a bluff body (BB) is performed. The modified Rayleigh number based on the total heat input and the BB diameter is set at 1.2x10^<10>. The entrainment coefficient showed definite increase in a wide range above the BB in the case with an adiabatic BB. Moreover, turbulent intensities, skewness factor and flatness factor in the same case also show considerable difference with other cases; with a heated BB and without BBs. These variations suggest that vertical vortices exist in the central region above an adiabatic BB and are relevant to the increase of entrainment there.
