Papers

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    Numerical analysis of helicopter’s blade pitch link loads
    ( 2020) Madeira, A. ; Roucoules, L. ; Malburet, F. ; Serr, C. ; Kelaidis, M.
    The industrial process for the design of main rotor blades is more and more challenging. Taking into account the loads aspect in the blade design process became necessary to ensure a blade design that can be relevant with a high-speed usage. This paper presents the last results of recent studies about pitch link loads. Within the framework of the CHAllenge AeRothermoMEchanique project (CHARME) an important study has been made in order to understand and to improve the control loads prediction capability. The first part of this work was to identify the correct model to be used. A large study was done in order to understand different model’s effects, validity domain and relevance. The main goal of this part was to identify the most relevant aerodynamic modeling base to be used for the next step. All the models used are included in our global aeromechanic code. The second part of the work was to use this modeling base to identify the blade’s pitch link load of a state-ofthe-art main rotor blade during a high-speed forward flight.
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    Flight simulation testing of a turbulence model based on a Synthetic Eddy Method
    ( 2020) Huecas, S.G. ; White, M. ; Barakos, G.
    This paper presents initial analysis of an ongoing series of flight simulation trials of a new turbulence model based on a synthetic eddy method (SEM). The model is based on the generation of a random distribution of turbulence generating Eddies within a control model surrounding the aircraft. Eddies are displaced by the flow and regenerated at the inflow as they leave the simulation domain. The model allows adjustment of turbulence intensity by adjusting the value of Reynolds stress tensor and of frequency spectra through adjustment of eddy sizes, allowing for a more realistic representation of broadband turbulence. Compared to other random turbulence models, preserving the location of the Eddies in the control volume ensures automatically that turbulence across different aircraft locations is automatically correlated. Piloted flight simulation tests show that both, levels of turbulence intensity and frequency of the induced turbulence have a strong effect on workload and task performance. Increases in turbulence intensity result in a direct increase in pilot workload and reduced task performance. However changes in frequency of turbulence present a more complex picture dependent on flight condition and aircraft response.
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    Electro-mechanical de-icing system for a non-rotating structure of small and medium sized helicopters synthesis of a helicopter control system using inverse dynamics and its upgrade with the use of a sidestick controller
    ( 2020) Efremov, A.V. ; Efremov, E.V. ; Mbikayi, Z. ; Esaulov, S.Y. ; Ivchin, V.A. ; Myasnikov, M.I.
    The modern trend of developing highly automated aircraft is characterized by a transition from traditional methods and technical solutions to innovative approaches of creating control systems, inceptors and displays. This paper deals with the development of helicopter control systems based on the inverse dynamics and its integration with a novel type of side stick shaping the pilot output signal such that it is proportional to the control force (Force Sensing Control – FSC). The synergetic asset arising from this integration is also evaluated. The evaluation of the effectiveness of the inverse dynamics was carried out through mathematical modeling of the pilot-aircraft system ground based simulations.
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    Rotor parameters of small weight helicopters
    ( 2020) Dudnik, V. ; Karabut, V. ; Lesniak, S.
    In recent years, a significant number of one and two-seats small weighted helicopters have appeared. This fact makes it possible to analyse the parameters and determine the parameter dependencies for this helicopters class. Knowledge of such dependencies is necessary for the preliminary design stage. The analysis performed in this paper and the comparison of it with the statistical data of all the categories of helicopters made it possible to determine the necessary corrections in the methods for design the parameters of the little helicopter's rotor systems.
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    Conceptual design and performance analysis software tool for rotorcraft systems
    ( 2020) Figueiredo Ventura Pimentel Fontes, T. ; Szolnoky Ramos Pinto Cunha, F.
    The availability of a free open source tool for the design and performance evaluation of rotary wing aircrafts is scarce, this work intends to provide a solution for engineering students, aircraft engineers or anyone interested in aircraft design with such a tool. The tool applies the Momentum theory and the Blade Element theory to execute the analysis of the rotor performance and presents the results in a clear and simple way (power against airspeed plots, rotor disk distribution plots of the calculated variables, as well as numerical results explicitly identified). A small data base with airfoils (and their aerodynamic performances) is included in the tool. The tool’s results validation is done and presented to assure the user of the reliability of the analyses done.