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During an aircraft taxiing on a water-contaminated runway, the worn tires with shallower grooves will significantly deteriorate the safety of take-off and landing. The hydrodynamics generated by the tire-water-pavement interaction is numerically studied using the coupling method of Smoothed Particle Hydrodynamics and Finite Element Method. By comparing a completely worn tire with a new tire, the effects of tire wear on water spray and water displacement drag are analyzed. With the increasing tire speed and water film depth, the water spray composed of bow wave and side plume increases, and the water displacement drag decomposed of wave- and film-generated components also increases. The effects of tire wear depend on the relative height of tire grooves to the water film depth. For the shallow water film with a depth smaller than the grooves height, the water spray and water displacement drag of new tire is much smaller than those of worn tire, because the groove drainage effect can work very well. While for the deep water film that completely floods the grooves, the water spray and water displacement drag of new tire are similar with those of worn tires, because the groove drainage effect cannot be fully utilized. [ABSTRACT FROM AUTHOR]

During the taxiing of an aircraft on a water-contaminated runway, the rolling tires impact water film resulting in a considerable water displacement drag and a large amount of spray, which will affect the safety of take-off and landing. The characteristics and flow mechanism of the water displacement drag generated by an elastic tire are numerically studied based on the coupling method of Smoothed Particle Hydrodynamics and Finite Element Method. The water displacement drag is divided into wave-generated drag and film-generated drag based on flow mechanism for the first time, and the former is much larger than the latter. The water displacement drag satisfies the Gaussian distribution along the rotation axis. The longitudinal grooves cause a significant increase in the wave-generated drag and a reduction in the film-generated drag. A simple potential flow model around a semi-infinite bluff body is proposed to reveal the flow physics of film-generated drag. Two drag formulas are proposed to quickly predict the wave-generated drag and film-generated drag. [ABSTRACT FROM AUTHOR]