飞机轮胎溅水鸡尾流特性数值模拟

当飞机起落架的多轮经过涉水跑道时，除侧向溅水之外，在轮胎之间由于两股侧向水流汇聚，会形成类似公鸡尾的溅水形态，称之为鸡尾流。相比于轮胎的侧向溅水，鸡尾流成因复杂，且水量更大，溅水高度更高，可能对飞机安全造成更严重的危害。采用数值分析方法对飞机轮胎溅水产生的鸡尾流现象成型机理开展研究。根据轮胎几何结构特点建立飞机轮胎溅水模型，其中轮胎及跑道采用FEM方法建模，积水模型采用SPH法，给出了鸡尾流的形态和速度分布，通过与侧向溅水形态分布的分析与比较，揭示了鸡尾流溅水的形成机制，并研究了水深、轮胎间距、轮胎速度等因素对于鸡尾流形态以及速度分布的影响规律，初步验证了ESDU工程算法对于无翻边轮胎鸡尾流形态描述的可参考性。

Numerical simulation of cock-tail water spray flow generated by aircraft tire

When the tires of the landing gear of the plane pass through the contaminated runway, they will create not only lateral water splashing, but also water splashing similar to the tail of the rooster, which is caused by the convergence of water between multiple wheels. This water spray is called cock-tail flow. Compared with the lateral splashing of tire, the formation of cock-tail flow is complicated. The amount of water is larger and the height of splash is higher than lateral splashing, which may cause more serious harm to the safety of aircraft structure. In this paper, numerical analysis is used to study the formation mechanism of the cock-tail flow caused by the main aircraft tires. Based on the geometrical characteristics of the aircraft tire, a model for the slashing water of aircraft tire is established, in which the tire and runway are simulated by the FEM method and the water is simulated by the Smoothed Particle Hydrodynamics (SPH) method. The shape and velocity distribution of cock-tail flow are presented, revealing the formation mechanism of cock-tail flow water splashing. The effects of water depth, tire spacing, and speed of tire on the shape and velocity distribution of cock-tail flow are studied. Results preliminarily verified that the ESDU engineering algorithm can be used as a reference for describing the shape of cock-tail flow in flangeless tire.