Lagrangian model for deposition from low-concentrated particles-laden turbulent jets

Abstract

Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.

This work presents a simple model that accurately predicts the deposition from low-concentrated particle-laden turbulent jets in different scenarios. Our proposed model is a developed Lagrangian model that takes advantage of the preferential concentration phenomenon. The unidirectional coupling (fluid- sediment) is used in the modelling. This choice is adopted because when the concentration of solid particles is small enough, it does not affect the hydrodynamic development of the jet. The deposition criterion states that the particle deposits when its settling velocity is greater than the vertical component of the entrainment velocity. Six experiments chosen from the available literature are used to validate the model. These experiments cover the cases of horizontal and inclined buoyant jets in stationary ambient, horizontal buoyant jets in coflow current and nonbuoyant horizontal jets in stationary ambient. Good agreement between the experiments and the obtained simulations is revealed. A sensitivity analysis study is conducted in order to investigate the role of the model main variables. We found that the most important variables are respectively the settling velocity of solid particles, the jet initial velocity, ambient velocity and the buoyancy forces.