Shirazi, Alireza SarrafFrigaard, Ian2018-11-082018-11-08May-18978-1-77355-023-7http://hdl.handle.net/10315/35357http://dx.doi.org/10.25071/10315/35357Paper presented at 2018 Canadian Society of Mechanical Engineers International Congress, 27-30 May 2018.A modified three-layer model for solid-liquid flow in horizontal pipes is developed, which overcomes the limitations of many previous models. The steady-state model predicts the pressure loss, critical velocity, concentration profile in the heterogeneous layer, mean heterogeneous layer and moving bed layer velocities, and bed layer heights for each set of parameters. We propose a new correlation for the turbulent solids diffusivity. This and the steady state model predictions show a good agreement with experimentally measured results in literature: for concentration profile in the heterogeneous layer and pressure loss, over a wide range of conditions [1]. In turbulent flow. the pressure loss vs mean velocity curve shows a characteristic minimum just before the critical velocity is attained.enThe copyright for the paper content remains with the authorFluid MechanicsThree-layer modelSolids transportCritical velocitySolids diffusivityPressure gradientArticle