适用于直升机俯仰与滚转机动分析的广义动态尾迹模型

现有的直升机操纵响应计算方法，给出的他轴耦合响应往往与飞行实测结果符号相反，这是由于仿真模型未计入机动时的尾迹弯曲。本文建立了尾迹弯曲的模型，推导出角速率与一次谐波入流分量之间的关系，据此对旋翼的广义动态入流模型进行了增广和修正；以某机型为算例，分析了直升机俯仰或滚转运动对他轴耦合响应的影响。本增广模型为通用模型，适用于任意机型，无需依赖特定机型的经验公式，即可正确计算直升机的他轴响应。

Generalized Dynamic Wake Model Applied to Helicopter Pitching and Rolling Maneuver

The predicted helicopter off-axis response based on existing simulation codes often displays the opposite sign as compared to flight tests. This incorrectness is due to neglect of wake distortion during helicopter pitching or rolling maneuver. A new wake model with the distorted geometry is founded. Starting off with vortex tube theory, the relationship between the angular rates and the first harmonic inflow is deduced, and then the generalized model of main rotor dynamic inflow is modified. Based on the distorted wake model, the effect of helicopter pitching and rolling movements on off-axis coupling response is analyzed. And the calculational example shows that the new model rectifies the mistake of sign reversal predicted by existing calculational methods. This model is correctly used to compute the off-axis response for arbitrary configuration helicopters and it is needless to depend on any empirical formulas or experimental data.