Development of a new k–ε model to reproduce the aerodynamic effects of snow particles on a flow field. Issue 144 (September 2015) - Okaze, T.
Abstract: This study aims to develop a new k–ε model that incorporates the effects of snow particles on a flow field. In the first part of this paper, the results of wind-tunnel measurements of a flow over a loose-snow surface are presented. The spatial distributions of the mass flux of drifting snow, wind velocity, and turbulence were simultaneously measured under several different wind-speed conditions. The wind-tunnel data clearly show that wind velocity near the snow surface decreased because of the snow particles. In the latter part of this paper, the basic equations of the k–ε model are modified to include new terms to express the effect of snow particles as moving obstacles on a flow field based on the concept of canopy-flow modeling. The model parameters included in the new terms, namely, R p [which is a model parameter related to the moving particle speed in terms of the wind velocity (0< R p <1)] and C pε (which is a model coefficient included in the transport equation of energy dissipation rate), are optimized by comparing the wind-tunnel measurements and computational fluid dynamics predictions.