In Chapter 3, based upon the blade second-order lifting-line model and rotor free-wake model, an analytical method is developed for predicting the rotor wake structure and BVI airload.

基于桨叶二阶升力线理论和旋翼自由尾迹模型，本三章建立了一个适合于直升机旋翼尾迹结构桨-涡干扰气动特性分析的方法和模型。