Aerodynamic performance design and experimental study on contra-rotating propfan

As an ideal propulsion system for future military transport and mainline civil aircraft, the contra-rotating propfan has attracted extensive attention and research interest owing to its high propulsion efficiency and fuel economy. However, studies on its aerodynamic performance design and systematic verification remain relatively limited. In this work, a systematic and closed-loop method for the aerodynamic design and verification of a contra-rotating propfan was established. First, the aerodynamic design was carried out based on the compressible lift-surface theory. Subsequently, numerical simulations were conducted to analyze in detail the aerodynamic performance and three-dimensional flow properties of the designed case. Finally, wind-tunnel experiments were performed to experimentally verify its aerodynamic characteristics. The results indicate that the designed case generally meets the performance requirements under typical flight conditions. Nevertheless, there remains potential for further optimization, particularly regarding the leading-edge flow separation under take-off condition, as well as the shock-wave formation in the tip region and the choked flow near the root under cruise conditions, which limit the performance of the contra-rotating propfan. A dedicated test platform for the contra-rotating propfan was designed and fabricated. Wind tunnel tests demonstrate that the platform operates stably, with the accompanying rotating balance measurements showing good repeatability and a maximum deviation of less than 2%, confirming the accuracy and validity of the measurements. Furthermore, the numerical results show good agreement with the experimental data, with deviations of 2.5%, 0.5%, and 0.1% under take-off, climb, and cruise conditions, respectively. This consistency demonstrats that the current numerical simulation method is accurate and reliable for evaluating and verifying the aerodynamic performance of contra-rotating propfan.