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.
Experimental results of the European HELINOISE aeroacoustic rotor test
In a cooperative research program between eight European partners, a 40% geometrically and dynamically scaled and highly instrumented model of the ECD (formerly MBB) BO 105 helicopter main rotor was tested in the open-jet anechoic test section of the German-Dutch Wind Tunnel (DNW) in the Netherlands. The primary objectives of this experimental study were 1) to improve the physical understanding of the impulsive rotor noise sources by correlating blade pressure and acoustic characteristics and 2) to provide an extensive airload and acoustic database for code validation purposes.Consequently, a comprehensive set of simultaneous acoustic and aerodynamic blade surface pressure data as well as blade dynamic and performance data were measured for the standard rotor with rectangular blade tips. In addition, initial quantitative information of the blade- vortecx miss distance during blade-vortex interaction (BVI) was obtained.
SUSTAINABLE URBAN DEVELOPMENT AND URBAN REGENERATION DUMITRESCU
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.