A fully resolved numerical simulation of turbulent flow past one or several spherical particles

The flow past one or nine spheres arranged in a plane lattice held fixed in a stream of decaying homogeneous isotropic turbulence is studied by means of fully resolved Navier-Stokes simulations. The particle radius is 3-5 times the Kolmogorov length and about 1/3 of the integral length scale. The mean particle Reynolds number is 80 and the turbulence intensity 17% and 33%. Several features of the flow are described: the mean and fluctuating dissipation and its spatial distribution, the mean and fluctuating hydrodynamic forces on the spheres, stimulated vortex shedding, and others. A special attention is paid to the relation between the work done on the fluid by the particles (in the reference frame of the former) and the total dissipation. It is shown that these quantities, which are assumed to balance in many point-particle models, can actually be very different when inertial effects are important. (C) 2012 American Institute of Physics. [doi: 10.1063/1.3678336]