Heat transfer in sheared dilute suspensions: a Lattice-Boltzmann study

To study the influence of dispersed solid particles on the heat transfer in shear flows, we consider a laminar shear flow (plane Couette flow) between to parallel (nonslip) walls moving in opposite directions with the same speed. The walls are kept at fixed (and different) temperatures while the domain is double periodic in the plane parallel to the walls. A spheroidal particle of different heat diffusivity than the base fluid is placed in the middle of the Couette flow. Because of the shear, the particle is a subject of rotation, which enhances the fluid mixing and influences the heat transfer properties of the suspension.

The numerical simulation of the conjugated heat transfer problem are performed by means of two coupled D3Q19 Lattice-Boltzmann equations under the BGK approximation for velocity and temperature fields and MolecularDynamics simulations for the particles motion. The results of the simulations are benchmarked against known analytical solutions for simple shear creeping flow and for conjugated heat transfer in quiescent fluids. We find evidences for heat transfer enhancement due to the particles’ rotation in the shear flow. The dependence of the Nusselt number1 , Nu, on the Peclet number2 , Pe, at different particles’ volume fractions, heat diffusivity ratios and particle aspect ratios is studied. An example is presented in Fig. 1.


by  V.S. L’vov∗ , I. Procaccia∗ , O. Rudenko† and F. Toschi†