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Relativistic aerodynamics of spinning black holes [PDF]
Astrophysical black holes do not exist in vacuum, and their motion is affected by the galactic environment. As a black hole moves it attracts stars and matter, creating a wake that, in turn, exerts an effective friction slowing down the black hole. This force is known as dynamical friction, and has significant consequences, ranging from the formation ...
Conor Dyson+3 more
semanticscholar +9 more sources
Nonlinear Model and Ballistic Impact of Body Aerodynamics for Canard Dual-Spin Aircraft
Targeting the nonlinear issues of the canard dual-spin aircraft, which relies on the high-speed rotation of the afterbody for flight stability and achieves trajectory correction by adjusting the roll angle of the low-speed rotating forebody to alter ...
Xinxin Zhao+3 more
doaj +4 more sources
A comparison of Jabulani and Brazuca non-spin aerodynamics [PDF]
Wind-tunnel experimental measurements of drag coefficients for non-spinning Jabulani and Brazuca balls are presented. The Brazuca ball’s critical drag speed is lower than that of the Jabulani ball, and the Brazuca ball’s super-critical drag coefficient is larger than that of the Jabulani ball.
John Eric Goff+2 more
semanticscholar +4 more sources
The aerodynamics of a spinning shell [PDF]
The paper to which this abstract is meant to serve as a non-technical introduction contains the results of work undertaken at the request of the Ordnance Committee and is published with their permission. (1) The Problems of Experimental External Ballistics .—A spinning shell moving through the air is subjected in ...
Ralph Howard Fowler+3 more
openalex +5 more sources
Investigating the Knuckleball Effect in Soccer Using a Smart Ball and Training Machine [PDF]
The term knuckleball in sporting jargon is used to describe a ball that has been launched with minimal spin, resulting in a trajectory that is erratic and unpredictable.
David Eager+3 more
doaj +2 more sources
VII. The aerodynamics of a spinning shell.—Part II [PDF]
In a previous paper the authors, with others, have described observations of the angular oscillations of the axis of a 3-inch shell over the first 600 feet from the muzzle of the gun, and from an analysis of the observations have obtained information about the forces due to the air.
Ralph Howard Fowler, C. N. H. Lock
openalex +3 more sources
The combined influence of spin and roughness frequency on sphere aerodynamics [PDF]
The lift and drag of spinning spheres roughened with macro-roughness elements are examined. The velocity field of these same spheres in flight is measured with particle image velocimetry (PIV).
Jack Elliott+3 more
openalex +2 more sources
Spin Rate Measurements in Cricket Bowling Using Magnetometers
The ability to measure and classify spin has been of great interest to cricket organizations, coaches, and athletes. While video is common, an alternative approach is to use 3D motion capture analysis with reflective spheres, which changes the ...
Aswath Kumar+3 more
doaj +2 more sources
The Combined Influence of Spin and Roughness Frequency on Sphere Aerodynamics [PDF]
Abstract In this paper, the lift and drag of spinning spheres roughened with macro roughness elements are examined. The velocity field of these same spheres in flight is measured with Particle Image Velocimetry (PIV). Several spheres with varying roughness are examined at various spin rates and fixed Reynolds number.
Jack Elliott+3 more
openalex +2 more sources
Spiraling light: from donut modes to a Magnus effect analogy [PDF]
The insight that optical vortex beams carry orbital angular momentum (OAM), which emerged in Leiden about 30 years ago, has since led to an ever expanding range of applications and follow-up studies. This paper starts with a short personal account of how
Spreeuw Robert J. C.
doaj +2 more sources