The coaxial compound configuration has been proposed as a concept for future high-performance rotorcraft. The co-axial rotor system requires no anti-torque device, while the longitudinal thrust is provided by a propeller. A well-designed propeller can ensure both the performance and the cruise efficiency. The propeller design also influences the flight dynamics of such configuration. To design the propeller parameters of the coaxial compound helicopter, the propeller modelling and design method devised by Adkins and Liebeck is firstly introduced. A flight dynamics model of the coaxial compound helicopter is developed. Trim characteristics, power consumption results, and handling qualities features are calculated with variable propeller parameters at optimum (corresponding to the maximum flight range) and maximum speeds. The results indicate that the propeller parameters alter its efficiency and improve the performance characteristics of this helicopter. In addition, the propeller design also influences the flight dynamics characteristics and handling qualities of the coaxial compound helicopter, and consequently affect the power consumption indirectly. In this light, a design method for the propeller has been developed by formulating the design procedure into the nonlinearly constrained optimisation problem based on the flight dynamics characteristics. The method is demonstrated by evaluating propeller parameters to improve the performance in both optimum and high-speed range, which could also guarantee the handling qualities of the rotorcraft for related requirements.

同轴复合结构已经被提出作为未来高性能旋翼飞机的概念​​。同轴转子系统不需要反扭矩装置，而纵向推力则由螺旋桨提供。精心设计的螺旋桨可以确保性能和巡航效率。螺旋桨的设计也会影响这种配置的飞行动力学。为了设计同轴复合直升机的螺旋桨参数，首先介绍了由Adkins和Liebeck设计的螺旋桨建模和设计方法。建立了同轴复合直升机的飞行动力学模型。使用可变的螺旋桨参数以最佳（对应于最大飞行范围）和最大速度来计算修剪特性，功耗结果和操纵质量特性。结果表明，螺旋桨参数改变了其效率并改善了这架直升机的性能特征。此外，螺旋桨的设计还会影响同轴复合直升机的飞行动力学特性和操纵质量，从而间接影响功耗。有鉴于此，通过基于飞行动力学特性将设计程序公式化为非线性约束优化问题，从而开发了一种螺旋桨的设计方法。通过评估螺旋桨参数以改善最佳和高速范围内的性能来证明该方法，这也可以确保旋翼飞机满足相关要求的操纵质量。