The role of thermally evolving particles in Rayleigh-Bénard turbulent mixing

Thermally-evolving, multiphase flows are prevalent across industrial and natural processes, such as nuclear and circulating fluidized bed reactors, desalination systems and complex macrobiological systems. Despite their societal importance, tractable models capable of accurately predicting global quantities of interest have remained elusive. This is in large part due to the complex nature of these systems and the challenge in producing high-fidelity data, either computationally or experimentally. In this talk, we quantify the role of a dispersed phase in thermally evolving channel flow. Here, the walls are vertically oriented and held at opposing temperatures (one hot and one cold). We discuss the convective behavior of this vertically oriented Rayleigh-Bénard system, absent of particles first, then make comparisons with an analogous system seeded with isothermal particles at sufficiently high mass loading such that heterogeneous effects, such as clustering are observed. Finally, we extend this configuration to allow the particles to also evolve thermally. This work uses an open source Euler-Lagrange framework (NGA2) to generate a high-fidelity data spanning a range of particle volume fractions and Rayleigh numbers. This data is then used to quantify the convective behavior and a new scaling law is proposed for the Nusselt number that takes into account not only the Rayleigh and Prandtl numbers, but also disperse phase properties, such as mass loading and volume fraction.