Particle-wall adhesion model for turbulent disperse multiphase flows within an Euler-Lagrange LES approach

摘要: The present study is concerned with the particle-wall adhesion in turbulent particle-laden flows. In the framework of a four-way coupled Euler-Lagrange approach relying on the large-eddy simulation technique and a hard-sphere model with deterministic collision detection (inter-particle and particle-wall) a momentum-based wall adhesion model is developed. Taking the van-der-Waals force on dry electrostatically neutral particles into account, the condition for the deposition of particles on bounding walls due to sticking or sliding collisions including friction and inelasticity is determined. The modeling assumptions are in accordance with a recently developed agglomeration model [7]. The influence of the adhesive force on the deposition process is first studied in a turbulent particleladen channel flow under various conditions, eg, different sizes of the primary particles, smooth and rough walls, and different wall roughnesses. Finally, the new adhesion model is applied to study a practically relevant turbulent flow past an inclined airfoil with separation, transition and reattachment. That mimics in a simplified manner the icing problem and shows the necessity of an enhanced adhesion model.