A model is introduced for the carrier phase turbulence in a fluid-particle flow based on the volume-averaged equations for the kinetic energy of the carrier phase. The model shows the trends observed by experiment, that is, small particles attenuate turbulence while large particles augment turbulence. The change in turbulence intensity is correlated with the particle loading and the ratio of the particle diameter to the turbulence length scale. (C) 2000 Elsevier Science Ltd. All rights reserved.