Aeromechanical Analysis of a Smart Helicopter Rotor in Forward Flight
This paper deals with a smart system integrated into a helicopter blade aimed at giving an anhedral shape to the blade tip region to alleviate the blade-vortex interaction phenomenon that may cause reduced helicopter performance in terms of noise and vibrations. The blade tip morphing is obtained through the joint action of a magneto-rheological fluid (MRF) device, a shape-memory alloy ribbons- based (SMA) device and a set of concentrated masses properly distributed spanwise. The presence of this smart actuator (particularly the concentrated masses) inside the blades modifies the aeromechanical behaviour of the rotor and may be detrimental in terms of hub vibratory loads, pitch control effectiveness and aeroelastic stability. Following a previous literature work concerning with the effectiveness of the smart actuated rotor in hovering conditions, the present paper focuses on the aeromechanical effects due to the inclusion of the smart device in a four-bladed helicopter rotor in forward flight where blade morphing is not needed. Aim of this work is to investigate on the compatibility of the smart system with the required aeromechanical performance of the rotor, highlighting the feasibility of its application on helicopters.
A Novel Potential-Flow Boundary Integral Formulation for Helicopter Rotors in BVI Conditions
A direct panel method based on a novel boundary integral formulation for the velocity potential is presented and applied to helicopter rotors experiencing blade-vortex interaction (BVI). It avoids the numerical instabilities arising in the standard direct panel method in case of blade/wake impingement. This aerodynamic solver yields a unified approach for the calculation of free-wake evolution and blade pressure field. It is fully 3D, includes body thickness eects, and can be applied to blades with arbitrary shape and motion. Blade pressure predictions and the corresponding acoustic fields correlate well with wind tunnel test data for helicopter rotors in descent flight, where severe BVI occurs.
CULTURE, SUSTAINABLE URBAN DEVELOPMENT AND URBAN REGENERATION
Concerns about the conflict between economy, development on one hand and urban cultural heritage on the other hand, have made the urban development to be lately one of the most important themes at European level. Also, another issue of concern is social equity, aiming to strike a balance between economic development and equal access to culture for all generations of inhabitants of urban communities. Basically, ensuring these balances between urban cultural heritage, economy and social equity we express the essence of the concept of sustainable development from the perspective of culture. Urbanization is an ongoing process in all the cities of the world, but urban cultural heritage is a crucial element in the development of the cities and has an important impact over the quality of life of that community. Castles, churches, fortresses, squares and public buildings all contribute at the creating of the community history and of their characteristics.