Browsing by Author "O'Rourke, Ciaran"

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    In-flight wingtip folding: inspiration from the XB-70 Valkyrie
    (Embry-Riddle Aeronautical University, 2019-05-16) Dussart, Gaétan; Lone, Mudassir; O'Rourke, Ciaran; Wilson, Thomas
    Wingip folding can be used to extend aircraft wingspan, allowing designers to take advantage of reduced induced drag whilst respecting ground operational limitations. Such devices can also be used in-flight for a variety of other benefits including load alleviation and flight control. The majority of in-flight folding research takes inspiration in past developments made on the XB-70 Valkyrie, which used the folding devices for stability and lift performance benefits. In this paper, the authors investigate the capabilities of the folding wingtip system and potential scaling to large civil aircraft. Manufacturing details are used to size the actuators whilst the aerodynamic loading acting on the wingtip hinges is found from flight test results. Dimensions and aerodynamic loading at cruise of a set of conventional civil aircraft wing are used to evaluate the scaling potential of the system for controlled in-flight folding. An estimate of the weight penalty due to the folding device is also given and compared to structural weight savings on the XB-70. The results presented herein help in the evaluation of conventional actuator limits for in-flight folding using arguably the most inspiring military example of wingtip folding so far.
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    Size estimation tools for conventional actuator system prototyping in aerospace
    (American Institute for Aeronautics and Astronautics, 2019-01-06) Dussart, Gaétan; Lone, Mudassir; O'Rourke, Ciaran
    Predicting the size of an actuator capable of reaching given performance requirements isa critical step for any systems design. Thus, to help in the prototyping and early developmentstages of such devices, simple mathematical models were developed, which can be used withlittle knowledge in actuation system design. Based on physical phenomenons at the heart ofthe actuation mechanism, these models can be used to estimate diameter and length, and there-fore volume and weight of conventional actuators as a function of performance requirements.Models include linear hydraulic pistons and electric motors, divided into radial and axial fluxmachines. Off-the-shelf actuators and more aerospace specific products were used to validateand assess the accuracy of the models over a wide range of force and torque requirements.Simple sizing examples for aerospace actuation systems are also given as use-cases of the different tools. A discussion on model applicability, for various aircraft scales and applicationsconcludes the paper.