Airfoil Preference and Adjustable Camber Impact Analysis for Trans-Medium Fixed-Wing Vehicles

The key to the realization of air-water trans-medium flight lies in the profile design of trans-medium flight and the satisfaction of different requirements of aerodynamic efficiency for air cruise and airfoil for underwater glide. In this paper, a trans-medium flight profile scheme based on the fusion design of traditional fixed-wing vehicles and underwater gliders was proposed with a small trans-medium vehicle as the platform. Several typical working conditions were determined, and alternative airfoils based on NACA00 and NACA44 series were selected according to the working conditions. The compressible flow model of Fluent was used to carry out numerical analysis on the alternative airfoil set. The aerodynamic and hydrodynamic characteristics of the alternative airfoils in air and water, such as lift-to-drag ratios, lift line slope, lift and drag coefficients, and torque coefficients were calculated by numerical simulation, which were then used as the optimal objective function and constraint conditions of the airfoil of the trans-medium fixed-wing vehicle. The relationship between the preferred airfoil under the underwater navigation profile and the corresponding flight/underwater motion parameters was emphatically analyzed, especially the influence of the change in airfoil camber on the underwater endurance time and range, so as to provide the airfoil optimization decision for the scheme design of the trans-medium vehicle, and the established analysis process can provide a reference for the parameter optimization of the airfoil.