Journal of Aerosol Science, Vol.26, No.5, 813-840, 1995
A SUBLAYER MODEL FOR WALL DEPOSITION OF ELLIPSOIDAL PARTICLES IN TURBULENT STREAMS
A sublayer model for deposition of ellipsoidal particles from turbulent streams on a smooth wall is developed. The analysis is based on the motion of ellipsoidal particles in the coherent vortices of near-wall turbulence. The vortical velocity field is simulated by using a sequence of viscous stagnation point flows with a superposed streamwise turbulence mean flow. The equations of particle motion include the hydrodynamic forces and torques, the shear-induced lift and the gravitational force. Euler's four parameters (quaternions) are used for describing the time evolution of particle orientations. Trajectories of ellipsoidal particles in the modeled flow field are evaluated and the differences with those of their spherical counterparts are discussed. Based on the observed trajectories and an averaging procedure, the inertia-interception deposition velocities under various conditions are evaluated. The effects of particle size, aspect ratio, particle-to-fluid density ratio, and gravity on deposition velocity are studied. The model predictions are also compared with several available experimental results, and favorable agreements are observed.