PARTICLE SIZE DISTRIBUTION IN A PLANAR JET FLOW UNDERGOING SHEAR-INDUCED COAGULATION AND BREAKAGE

A CFD simulation is performed for a particle-laden planar jet flow. The Reynolds number is 8300, and the initial particle diameter is 1 μm. Large Eddy Simulation (LES) is employed to calculate the flow field, and the Taylor-series expansion moment method (TEMOM) is adopted to deal with the balance equation of particle coagulation and breakage. The shear-induced coagulation kernel, power-law breakage kernel and symmetric fragment distribution function are involved. The prediction of the distribution of the mean streamwise velocity of the jet is in good agreement with experimental data. The evolution of particle number concentration, volume concentration, polydispersity, particle diameter and standard geometric deviation is discussed in detail. The results show that as the jet travels downstream, the particle number concentration and volume concentration decrease, while their spans become wider. The polydispersity and particle diameter are very large in the shear layers at the upstream and in the core of vortex structures at the downstream. The particle standard geometric deviation changes within the range of 1.32 ≤σ_g ≤1.96, and increases sharply in the shear layers. All variables approach the steady-state as time progresses.