Direct numerical simulation of the passive heat transfer in a turbulent flow with particle

Abstract

Abstract. Turbulent non-isothermal fully developed channel flow with solid particles was investigated through Direct Numerical Simulation combined with the point-particle approach. The focus was on the interactions between discrete and continuous phase and their effect on the velocity and the temperature of the particles. It has been found that low momentum inertia particles have a mean temperature similar to the fluid temperature and this effect is almost independent of particle thermal inertia. For particles with larger momentum, the inertia thermal effect is more complex, particle temperature in the near-wall and buffer region is significantly lower than the fluid temperature. The difference between the fluid mean temperature and particle mean temperature increases along with the momentum response time. This may have important consequences on the chemical reactions, technological processes and on the accuracy of temperature measurement techniques based on seeding particle.

The impact of the atmospheric turbulence-development tendency on new particle formation: a common finding on three continents

“…They attributed it to the decreases in the evaporation of existing particles by considering the interaction between the particle-phase volume fraction and the fluid-phase velocity fluctuations. This helps to explain why NPF occurs in an unstable layer, where new mixing production causes a granular temperature gradient when the upstream boundary of the cluster velocity field is highly compressed [ 53 ]. Under such a circumstance, fluctuation appears and facilitates more collisions, facilitating nucleation to occur more easily, as was shown by Monte-Carlo simulations [ 54 , 55 ].…”