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Yang Mao - One of the best experts on this subject based on the ideXlab platform.

  • Aerodynamic Modeling of High-Aspect-Ratio Wing Based on UMARC
    Science Technology and Engineering, 2010
    Co-Authors: Yang Mao
    Abstract:

    The aeroelastic characteristic of High-Aspect-Ratio fixed wing and that of rotor blade on a helicopter were analogical. Enlightened by this idea, an effort was made to mend the UMARC theory, which could be used to establish the aeroelastic models of rotor blade, so as to gain a method adaptive to aerodynamic modeling of High-Aspect-Ratio fixed wing with large deflection. The High-Aspect-Ratio fixed wing was treated as an Bernoulii-Euler beam. By dealing with the transformation of the coordinates correlated to the deformed and undeformed wing, expressions of the velocity in the deformed wing section and aerodynamic loads at a given moment were deduced. Employing the modeling method mentioned here, the steady state equilibrium solutions were gained. By comparing with the result in the reference, the effectiveness and accurateness of the method is validated.

  • Dynamic analysis on High Aspect Ratio composite wing
    Computer-Aided Engineering, 2008
    Co-Authors: Yang Mao
    Abstract:

    With the issue that structural nonlinearity has great effect on dynamic characteristics of High Aspect Ratio wing,the finite element modeling is built for High Aspect Ratio composite wing by using MSC Patran and Nastran,which is modeled as a thin-walled box beam.The effects of large deflections on dynamic characteristics of wing are studied.The computation results of composite box beam model are compared with metal box beam model.The effects of ply sequence of composite on dynamic characteristics are also discussed.The results indicate that the natural frequency of composite wing are Higher than that of aluminum alloy wing,and ply sequence can influence the natural frequency of composite wing.

Michael H. Huang - One of the best experts on this subject based on the ideXlab platform.

Afzal Suleman - One of the best experts on this subject based on the ideXlab platform.

  • A review on non-linear aeroelasticity of High Aspect-Ratio wings
    Progress in Aerospace Sciences, 2017
    Co-Authors: Frederico Afonso, J. Vale, É. Oliveira, Fernando Lau, Afzal Suleman
    Abstract:

    Abstract Current economic constraints and environmental regulations call for design of more efficient aircraft configuRations. An observed trend in aircraft design to reduce the lift induced drag and improve fuel consumption and emissions is to increase the wing Aspect-Ratio. However, a slender wing is more flexible and subject to Higher deflections under the same operating conditions. This effect may lead to changes in dynamic behaviour and in aeroelastic response, potentially resulting in instabilities. Therefore, it is important to take into account geometric non-linearities in the design of High Aspect-Ratio wings, as well as having accurate computational codes that couple the aerodynamic and structural models in the presence of non-linearities. Here, a review on the state-of-the-art on non-linear aeroelasticity of High Aspect-Ratio wings is presented. The methodologies employed to analyse High Aspect-Ratio wings are presented and their applications discussed. Important observations from the state-of-the-art studies are drawn and the current challenges in the field are identified.

Khalil Najafi - One of the best experts on this subject based on the ideXlab platform.

  • High Aspect-Ratio polysilicon micromachining technology
    Sensors and Actuators A: Physical, 2000
    Co-Authors: Farrokh Ayazi, Khalil Najafi
    Abstract:

    This paper presents a single wafer, all-silicon, High Aspect-Ratio multi-layer polysilicon micromachining technology that combines deep dry etching of silicon with conventional surface micromachining to realize tens to hundreds of microns thick, High Aspect-Ratio, electrically isolated polysilicon structures with sub-micron air-gaps. Vertical polysilicon sense electrodes as tall as the main body polysilicon structure can be realized in this technology. A 70-μm-tall, 2.5-μm-wide polysilicon vibrating ring gyroscope with 1.2 μm capacitive air-gaps and electrodes as tall as the ring structure has been fabricated using this technology. Vertical polysilicon beams that are 220 μm tall with a 100:1 Aspect-Ratio have been also fabricated. The all-silicon feature of such a technology improves long term stability and temperature sensitivity, while fabrication of large area, vertical pick-off electrodes with sub-micron gap spacing will increase the sensitivity of MEMS devices by orders of magnitude. This technology is also capable of simultaneously producing electrically isolated 2-D (planar) and 3-D (vertical) polysilicon structures on the same silicon substrate.

Wan-ling Huang - One of the best experts on this subject based on the ideXlab platform.