湿滑条件下基于真实纹理道面的机轮着陆滑水行为解析

湿滑条件下的着陆滑跑是航空事故的高发区。为较为真实地反映湿滑条件下机轮的滑跑行为，需要建立包含真实道面纹理特征的滑跑模型。在提取真实道面形貌特征的基础上，通过解析湿滑条件下的机轮滑跑行为进一步反算其遵循的摩擦关系，以获得更加接近真实条件的摩擦模型；然后运用欧拉-拉格朗日（CEL）算法建立基于真实纹理形貌特征的道面-水膜-轮组的流固耦合模型，以摩擦因数、动水压力为分析指标来探讨速度、滑移率、水膜厚度以及道面类型对机轮滑水行为的作用规律，进而为提高飞机着陆的安全性提供理论参考。研究结果表明：A320型飞机着陆可能滑漂的危险区段为刚刚着陆阶段，随着速度的降低，道面支撑力会逐渐增大，而动水压力将逐渐减小；随着滑移率的增加，动水压力呈现出先减小后增大的趋势，当滑移率为0.15时，动水压力达到最小；关于水膜厚度的影响，水膜厚度小于3 mm时不会发生滑漂，而水膜厚度大于10 mm时极可能发生滑漂；当水膜厚度为7 mm时动水压力与飞机滑行速度、滑移率的相关性较大，可视为机轮发生滑漂的临界状态；最后，在其他条件一致的情况下，各道面类型的抗滑性排序为SMA > OGFC > AC > 平滑道面。因此，湿滑条件下，控制飞机着陆的初始速度和滑移率是减小航空事故、提高机场安全运行的有力保障。

Analysis on the Hydroplaning of Aircraft Tire Under Real Texture Pavement Conditions

In the aviation industry, aircraft safety is mainly focused on the landing stage. Furthermore, wet road conditions are the main cause of accidents during landing. To accurately reflect the hydroplaning of an aircraft tire, it is necessary to develop a hydroplaning model under real texture pavement conditions. In the present study, based on real textures, a friction model was calculated to obtain a more realistic simulation of the tire. Furthermore, a fluid-solid coupling model among the tire, water film, and real texture pavement was established based on the Coupled Eulerian-Lagrangian (CEL) algorithm. The characteristic indexes, such as friction coefficient and hydrodynamic pressure, were extracted to express the relationship among influencing factors, including velocity, slip ratio, water film thickness, and pavement type were used to analyze the skiing behavior of aircraft tires under wet conditions. Hence, this provided a reference for aircraft landing safety. The results indicates that the hydrodynamic pressure gradually decreases and the support of the pavement gradually increases during the landing stage of A320. The most dangerous moment occurs at the beginning of the landing. The high velocity at the beginning of the landing of the aircraft results in a higher hydrodynamic pressure. The increase in the slip ratio causes the hydrodynamic pressure to decrease first and then increase. When the slip ratio is 0.15, the hydrodynamic pressure of the pavement reaches a minimum. When the water film is thin (3 mm), no drifting occurs. However, when the water film is excessively thick (10 mm), drifting can occur. The hydrodynamic pressure is significantly dependent on the velocity and slip ratio under critical wet conditions (7 mm). The results of the simulation under dry conditions indicates that the anti-sliding performance of each pavement type is Stone Matrix Asphalt > Open Graded Friction Course > Asphalt Course > Flat pavement. Thus, controlling the appropriate initial velocity and slip ratio is the most important guarantee for improving the safety of aircraft landing.