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In this work, particle transport in a fully developed turbulent 90° bend flow at the “electrostatic equilibrium” state is simulated using large eddy simulation coupled with Lagrangian particle tracking technique. The flow Reynolds numbers (based on bulk velocity) considered is from 34000 to 58000. Three particle size 5, 10 and 50 μm are considered and their corresponding Stnumber are from 2.2 to 547. Simulation results of the bend flow agree well with experimental data. The electrostatic field formed in the bend is symmetric in the spanwise direction but asymmetric in the vertical direction and radial direction, which is independent of Reynolds number. The minimum electrostatic field strength occurs at r/ra = 0.25 near the inner wall of the bend. Particles transported in a bend gradually accumulate near the wall due to turbophoresis, such trend is improved by electrostatics. In addition, under the effect of electrostatics, the plume pattern of particle distribution disappeared. Particle concentration at the inner wall of the bend is higher than that at the outer wall, which depends on the combined effect of electrostatics and Dean vortices in the bend.

Particle behavior in a turbulent flow in a circular pipe with a bed height h = 0.5Ris studied at Reb = 40,000 and for two sizes of particles (5 μm and 50 μm) using large eddy simulation, one-way coupled with a Lagrangian particle tracking technique. Turbulent secondary flows are found within the pipe, with the curved upper wall affecting the secondary flow formation giving rise to a pair of large upper vortices above two smaller vortices close to the pipe floor. The behavior of the two sizes of particle is found to be quite different. The 50 μm particles deposit forming irregular elongated particle streaks close to the pipe floor, particularly at the center of the flow and the pipe corners due to the impact of the secondary flows. The deposition and resuspension rate of the 5 μm particles is high near the center of the floor and at the pipe corners, while values for the 50 μm particles are greatest near the corners. Near the curved upper wall of the pipe, the deposition rate of the 5 μm particles increases in moving from the wall center to the corners, and is greater than that for the larger particles due to the effects of the secondary flow. The maximum resuspension rate of the smaller particles occurs above the pipe corners, with the 50 μm particles showing their highest resuspension rate above and at the corners of the pipe.