A dilute, particle-laden turbulent flow in a square cross-sectioned duct with a 90 degrees bend is modeled using a three-dimensional Eulerian-Lagrangian approach. Predictions are based on a second-moment turbulence closure, with particles simulated using a Lagrangian particle tracking technique, coupled to a particle-wall interaction algorithm and a random Fourier series method used to model particle dispersion. The performance of the model is tested for a gas-solid flow in a horizontal-to-vertical duct, with predictions showing good agreement with experimental data. In particular, the consistent use of anisotropic and fully three-dimensional approaches throughout yields predictions that result in fluctuating particle velocities in acceptable agreement with data. (C) 2011 American Institute of Chemical Engineers AIChE J, 58: 14-30, 2012