The Effect of Particle Collisions on Heat Transfer in a Non-Isothermal Dilute Turbulent Gas-Particle Flow

We analyze the effect of particle-to-particle collision on the heat transfer in a temporally evolving thermal mixing layer which develops between two isothermal regions in a homogeneous and isotropic turbulent flow. Eulerian-Lagrangian Direct Numerical Simulations in the two-way coupling regime are carried out in a wide range of particle Stokes number, from 0.2 to 3, with a thermal Stokes-number-to-Stokes-number ratio equal to 4.43, at a Taylor microscale Reynolds number up to 124. We quantify how much particle collisions tend to reduce the average heat transfer with respect to a collisionless regime and show that the overall effect is minor even at the higher Stokes number simulated.