Numerical investigations of ducted fan aerodynamic performance with tip-jet

Tip-jet technology has the potential value for application in vertical take-off and landing or short take-off and landing concept aircraft. The main objective of this work is to present a rapid prototyping method to model the power of the tip-jet during the concept design phase, and to investigate the aerodynamic performance of a ducted fan with tip-jet in hover through numerical experiments. The calculated data of the rapid method was compared to the numerical results, while the comparative analysis of the performances of an open fan, a ducted fan and a ducted fan with tip-jet were carried out. The results indicate that the fan lift of the ducted fan with tip-jet was augmented by the jets which formed the Coanda effect on the suction surface of the blade to increase the circulation of the blade. The figure of merit of the ducted fan with tip-jet was reduced and slightly affected by the nozzle area. The flow field represents the same flow features when the nozzle works in subsonic to supersonic operational conditions.