Temperature fluctuations in particle-laden homogeneous turbulent flows

The statistical behavior of the fluid and particle temperatures in homogeneous two-phase turbulent hows are investigated via direct numerical simulations. The effects of the flow Reynolds number (Re-lambda), the Prandtl number (Pr), the particle response time (tau(p)), the ratio of specific heats (alpha), and the mass loading ratio (phi(m)) on the fluid and particle temperature statistics are studied. The results show that the particle temperature intensity decreases as the magnitudes of tau(p), Pr, alpha, and Re-lambda increase. Also, by decreasing the magnitudes of alpha and/or Pr, the difference between the particle velocity and temperature diffusivity coefficients increases. The ratio of particle:to fluid temperature intensities and the dissipation rate of the fluid temperature are affected by two-way coupling effects and decrease as the mass loading ratio increases; Additionally, with increased mass loading, the probability density function of the fluid temperature deviate more from the Gaussian distribution. (C) 1998 Elsevier Science Ltd. All rights reserved.