Results 251 to 260 of about 3,858,029 (303)
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Trapped Vortex in Ground Effect
AIAA Journal, 2002The effects of vortices trapped between a flat plate and a ground plane were studied in a wind tunnel experiment. The flat plate was mounted parallel to the ground to represent the lower surface of a generic road vehicle. Rectangular vortex generators mounted onto the plate were used to generate streamwise vortices between the plate and the ground ...
Darwin Garcia, Joseph Katz
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Ground Effects in STOL Operation
Journal of Aircraft, 1971The effects of operation near the ground are of primary importance in determining the takeoff and landing characteristics of STOL aircraft. A study is presented which compares the results of theoretical analysis with those of wind-tunnel tests using a fixed ground plane with blowing boundary-layer control as well as the moving belt ground plane.
L. GRATZER, A. MAHAL
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Aspects of ground effect modeling
The Journal of the Acoustical Society of America, 2011A recently published one-parameter ground model based on Darcy’s law is here generalized into a two-parameter model which depends on an effective flow resistivity and an effective layer depth. Extensive field measurements of the acoustic impedance of various ground types have been carried out for frequencies in the range from 200 Hz to 2.5 kHz.
Gunnar, Taraldsen, Hans, Jonasson
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Effect of Ground Permeability on Ground Return Circuits
Bell System Technical Journal, 1931The formulas for the self and mutual impedances of ground return circuits are derived without restricting the ground permeability. Curves are given to show the effect of a ground permeability 1.7 on the mutual impedance between two parallel ground return circuits with the wires lying on the ground.
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Aircraft Engineering and Aerospace Technology, 1960
An analysis is made or the basic principles which govern the operation of those air‐cushion devices otherwise known as ground‐effect machines (GEMs). Most of these vehicles can be defined as machines which operate in close proximity to the earth's surface without ever physically touching it because they are always separated from it by a cushion or a ...
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An analysis is made or the basic principles which govern the operation of those air‐cushion devices otherwise known as ground‐effect machines (GEMs). Most of these vehicles can be defined as machines which operate in close proximity to the earth's surface without ever physically touching it because they are always separated from it by a cushion or a ...
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Aerofoil ground effect revisited
The Aeronautical Journal, 1996AbstractSteady state aerofoil ground effect is studied both numerically and analytically. Discrete vortex and linear vortex panel methods are applied to a parabolic arc and symmetric Joukowski aerofoil,
C. Coulliette, A. Plotkin
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Trampoline Effect in Extreme Ground Motion
Science, 2008In earthquake hazard assessment studies, the focus is usually on horizontal ground motion. However, records from the 14 June 2008 Iwate-Miyagi earthquake in Japan, a crustal event with a moment magnitude of 6.9, revealed an unprecedented vertical surface acceleration of nearly four times gravity, more than twice its horizontal counterpart. The vertical
Shin, Aoi +2 more
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Grounding Support for Effective Collaborative Learning
International Conference on Computers in Education, 2019A common ground of knowledge is the foundation for collaborative learning. However, learners often do not know how to engage in beneficial grounding activities during collaboration, which highlights the need to support such activities and the development of grounding skills.
Harbarth, Lydia +2 more
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Arcing Grounds and Effect of Neutral Grounding Impedance
Transactions of the American Institute of Electrical Engineers, 1930This paper was written to review and extend the theory of overvoltages due to arcing grounds because of the increasing tendency to use impedances between the neutral point and the ground, thereby losing the advantage of the solidly grounded neutral. The ``third class conductor'' theory of Steinmetz is touched upon very briefly and is considered as not ...
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2009
This book aims to introduce you, our readers, to a new type of marine craft. At present there are still very few of these machines, though as long ago as the 1970s, a secret military craft of this type twice as large as a Boeing 747 airliner was already on trials in the Caspian Sea for the Russian Navy.
Liang Yun, Alan Bliault, Johnny Doo
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This book aims to introduce you, our readers, to a new type of marine craft. At present there are still very few of these machines, though as long ago as the 1970s, a secret military craft of this type twice as large as a Boeing 747 airliner was already on trials in the Caspian Sea for the Russian Navy.
Liang Yun, Alan Bliault, Johnny Doo
openaire +1 more source