CFD Study of an Annular-Ducted Fan Lift System for VTOL Aircraft

Aerospace

Yun Jiang¹  Bo Zhang²  Tao Huang² 

[1] UAV Research Institute, Northwestern Polytechnical University, 127 West Youyi Road, Xi’an 710072, China;

关键词: computational fluid dynamics (CFD);    vertical takeoff and landing (VTOL);    annular-ducted lift fan;    helicopter;    aircraft;    tip turbine;    tiltrotor;   

DOI  :  10.3390/aerospace2040555

来源: mdpi

【 摘 要 】

The present study aimed at assessing a novel annular-ducted fan lift system for VTOL aircraft through computational fluid dynamics (CFD) simulations. The power and lift efficiency of the lift fan system in hover mode, the lift and drag in transition mode, the drag and flight speed of the aircraft in cruise mode and the pneumatic coupling of the tip turbine and jet exhaust were studied. The results show that the annular-ducted fan lift system can have higher lift efficiency compared to the rotor of the Apache helicopter; the smooth transition from vertical takeoff to cruise flight needs some extra forward thrust to overcome a low peak of drag; the aircraft with the lift fan system enclosed during cruise flight theoretically may fly faster than helicopters and tiltrotors based on aerodynamic drag prediction, due to the elimination of rotor drag and compressibility effects on the rotor blade tips; and pneumatic coupling of the tip turbine and jet exhaust of a 300 m/s velocity can provide enough moment to spin the lift fan. The CFD results provide insight for future experimental study of the annular-ducted lift fan VTOL aircraft.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.