Analysis of interaction between aircraft tire and slush-contaminated pavement

The airport safety operation on the runway polluted by slush is very prominent during major snowstorms. However, there is a lack of an evaluation method related to aircraft operation on slush-contaminated pavement. Therefore, a critical velocity formula of aircraft tire is derived according to the tire stress on the slush surface, and a finite element model of tire-slush-polluted pavement interaction based on the SPH method is established. The influence of slush thickness and density on tire-slush-polluted pavement interaction is analyzed, and the relationship between slush density, slush water equivalent coefficient, and the threshold of slush thickness allowed for aircraft operation is determined by using the critical water ski velocity equivalence principle and data fitting analysis. It is indicated that, under slush specific gravity, the difference in the predicted critical tire speed between the proposed formula in this paper and the Engineering Sciences Data Unit (ESDU) critical “water skiing” speed formula is less than 4 %. Based on the relation between viscosity and density of slush, it is found that the viscosity of slush gradually decreases with the increase of density of slush and tends to the viscosity of water. When the slush density is constant, the critical velocity decreases with the increase of slush thickness, and the error with the theoretical result is 10.4 %. When the thickness of the slush is constant, the critical hazardous velocity of the wheel decreases with the increase of the density of the slush, and the error from the theoretical result is 6.5 %. According to the relationship between the density of slush and the water equivalent coefficient of slush, the threshold of slush thickness is between 17 and 24 mm when the water film thickness is 13 mm and the density of slush is 650-900 kg/m³, and it gradually decreases with the increase of density.