Investigation of snow particle transportation and accretion on vehicles

Abstract

Snow particle transportation and accretion on vehicles is investigated. Accumulation of snow on essential devices such as air inlets and outlets of engine cooling systems can lead to overheating, malfunction and finally to serious damage. Particle accretion on wings leads to performance losses and malfunction of control surfaces. The simulations are performed by solving the flow field in combination with a discrete phase model to calculate snow particle tracks. Snow accretion on critical surfaces is determined by applying a trapping boundary condition. A threshold value of the friction velocity is used to determine the onset of snow particle release from the seeding surface. Several models for the mass flow rate of snow particles being released are examined. The simulation model which quantifies the mass of particles accumulating on surfaces under interest is enhanced by taking the variation of local surface geometry according to the accretion rate of particles into account. The numerical model presented is compared to experiments carried out in the climatic wind tunnel of the RTA - Rail Tec Arsenal. The mass flow rate of snow particles accumulated on a simplified model is analyzed and compared to numerical results. Applications presented are taken from the railway industry as well as the aircraft industry.