Abstract: Trans-media vehicles are an innovative aircraft with long-range rapid striking, repeated entry, and efficient penetration capabilities. However, the turbine working parameters of trans-media vehicles at different stages differ significantly. To realize the aerodynamic design of shared turbines for underwater, in-flight, and takeoff conditions, loss model is integrated to come up with an air-water shared turbine design. Numerical method is used to verify the accuracy of mean-line design method and the feasibility of takeoff conditions. The results show that the relative error between the numerical results and mean-line design results is within 2% under various working conditions. The numerical loss breakdown method is then used to further analyze the turbine losses and reveal that profile loss is the main loss of the air-water shared turbine. The shock waves and separation vortices are found in the passage under underwater conditions. In addition, the partial admission ratio is also very low, resulting in a relatively high loss. During flight, the flow is more uniform and hence the loss is smaller. During takeoff, the turbine works at an off-design point. The output power relies on the underwater nozzle, while air nozzle generates negative power. This study can provide a reference for the optimal design and experiment of air-water shared turbines.

Key words: air-watersharedturbine, trans-mediavehicle, partialadmission, designmethod, lossbreakdown