Sustaining flight operation that encounters with rainfall might be a challenge to a pilot due to lacking of understanding flight dynamics in the rain conditions. This paper, combined with a computational fluid dynamics (CFD) technique, develops a nonlinear flight dynamics model in the rain conditions that can be capable of exploring UH-60A single-rotor helicopter flight dynamics in the rain conditions, including trim, stability, and controllability. Firstly, in order to obtain a data-driven basis relating to multiple working conditions of the blades, a CFD-based method of simulation of the blade airfoil in the conditions of the angles of attack ranging from −26° to 26° and under a thunderstorm heavy rain scenario when the rate of rainfall is 1500 mm/h is developed. Then, these data are incorporated into a nonlinear flight dynamics model in the form of coefficient increments. Numerical simulations are conducted in the range of the flight velocities from 0 knots to 160 knots. The quantitative results indicate that rainfall degrades the blade airfoil aerodynamic performance and increases the rotor torque and required power, affecting the helicopter trim, stability, and controllability. More importantly, helicopter that flies in a small or moderate flight velocity and that encounters rainfall might be a relative serious case, which should be paid attention to.

由于缺乏对降雨条件下的飞行动力学的了解，维持遇到降雨的飞行操作对飞行员来说可能是一个挑战。本文结合计算流体动力学 (CFD) 技术，开发了一种降雨条件下的非线性飞行动力学模型，能够探索 UH-60A 单旋翼直升机在降雨条件下的飞行动力学，包括配平、稳定性和可控性。首先，为了获得与叶片多种工况相关的数据驱动基础，一种基于CFD的叶片翼型在攻角范围从-26°到26°的条件下和在开发了降雨速率为 1500 mm/h 时的雷暴大雨情景。然后，这些数据以系数增量的形式并入非线性飞行动力学模型。数值模拟在从 0 节到 160 节的飞行速度范围内进行。定量结果表明，降雨降低了叶片翼型的气动性能，增加了旋翼扭矩和所需功率，影响了直升机的配平、稳定性和可控性。更重要的是，以小或中等飞行速度飞行的直升机遇到降雨可能是一个相对严重的情况，应引起注意。定量结果表明，降雨降低了叶片翼型的气动性能，增加了旋翼扭矩和所需功率，影响了直升机的配平、稳定性和可控性。更重要的是，以小或中等飞行速度飞行的直升机遇到降雨可能是一个相对严重的情况，应引起注意。定量结果表明，降雨降低了叶片翼型的气动性能，增加了旋翼扭矩和所需功率，影响了直升机的配平、稳定性和可控性。更重要的是，以小或中等飞行速度飞行的直升机遇到降雨可能是一个相对严重的情况，应引起注意。