Extending helicopter handling qualities for vibratory loads
The aim of the present project is to develop a new approach to helicopter handling qualities analysis by developing new consistent, complementary criteria and testing techniques capable of being applied to both helicopter performance and vibratory loading investigations. Our proposal is based on two ideas:
- Up to the present no criteria, metrics or other test techniques have been ever elaborated for either helicopters capable to assess simultaneously the helicopter performance and the vibratory activity on the structure. The ‘lessons learned’ (some in the hard way) show that especially on the subject of structural and dynamic areas, there is a lack of adequate knowledge on how the pilot workload combines with the ‘work’ of the structure to external excitations.
- Experience has shown that helicopter handling qualities and hence much of a helicopter’s mission capabilities are largely committed in the early phases of the design process. For some time in the rotorcraft community there is a strong feeling that new inter-disciplinary handling qualities criteria are needed, capable of predicting the effects of the complex dynamic behaviour of these machines. It is the aim of this project to use the new concepts elaborated in this research in the process of multi-disciplinary design optimisation for structural load alleviation without compromising helicopter performance and manoeuvrability.
Exploratory ‘in house’ research on this subject has already been shown to be very promising [see Pavel & Padfield 2002, Pavel and Padfield 2003] highlighting optimised design solutions for the manoeuvrability and vibratory activity on the rotor. End products of the project will be: 1) new inter-disciplinary handling qualities criteria combining helicopter performance characteristics and the vibratory activity on the structure; 2) new techniques for structural load alleviation which do not alter the helicopter performance and manoeuvrability; 3) new guidelines in predicting the vibratory loads on the structure obtained from the application of the new handling qualities and dynamic behaviour criteria.
This project is part of the NITROS network.