Helicopter Tail Rotor Orthogonal Blade Vortex Interaction F.N. Cotona,∗, J.S. Marshallb, R.A.McD. Galbraitha, R.B. Greena aDepartment of Aerospace Engineering, University of Glasgow, Glasgow, G12 8QQ, U.K. bDepartment of Mechanical and Industrial Engineering and IIHR – Hydroscience and Engineering, The University of Iowa, Iowa City, IA 52242, U.S. Abstract The aerodynamic operating environment of the helicopter is particularly complex and, to some extent, dominated by the vortices trailed from the main and tail rotors. These vortices not only determine the form of the induced flow field but also interact with each other and with elements of the physical structure of the flight vehicle. Such interactions can have implications in terms of structural vibration, noise generation and flight performance. In this paper, the interaction of main rotor vortices with the helicopter tail rotor is considered and, in particular, the limiting case of the orthogonal interaction. The significance of the topic is introduced by highlighting the operational issues for helicopters arising from tail rotor interactions. The basic phenomenon is then described before experimental studies of the interaction are presented. Progress in numerical modelling is then considered and, finally, the prospects for future research in the area are discussed. ∗ Corresponding Author. Tel.: +44 141 330 4305, Fax.: +44 141 330 5560, E-Mail.:
[email protected] 1. INTRODUCTION..............................................................................................................................