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Relativistic aerodynamics of spinning black holes [PDF]
Physical Review DAstrophysical 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
arxiv +10 more sources
The Combined Influence of Spin and Roughness Frequency on Sphere Aerodynamics [PDF]
Experiments in Fluids, 2023 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
semanticscholar +5 more sources
A comparison of Jabulani and Brazuca non-spin aerodynamics [PDF]
Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, 2014 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
Spiraling light: from donut modes to a Magnus effect analogy [PDF]
Nanophotonics, 2021 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 +3 more sources
The aerodynamics of a spinning shell [PDF]
Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character, 1920 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
+7 more sources
Investigating the Knuckleball Effect in Soccer Using a Smart Ball and Training Machine [PDF]
Sensors, 2022 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]
Philosophical Transactions of the Royal Society of London. Series A, Containing Papers of a Mathematical or Physical Character, 1922 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.
C. N. H. Lock, Ralph Howard Fowler
openaire +3 more sources
Spin Rate Measurements in Cricket Bowling Using Magnetometers
Proceedings, 2020 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
Experimental studies of the aerodynamics of spinning and stationary footballs [PDF]
Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, 2008 The accurate discrimination of the aerodynamic parameters affecting the flight of sports balls is essential in the product development process. Aerodynamic studies reported to date have been limited, primarily because of the inherent difficulty of making accurate measurements on a moving or spinning ball.
Roy Jones +3 more
openaire +4 more sources
The lateral force on a spinning sphere: Aerodynamics of a curveball [PDF]
American Journal of Physics, 1987 The lateral force on a spinning baseball in a wind tunnel has been measured. The magnitude of the force is nearly independent of the orientation of the seams of the ball. The drag coefficient appears to be at most weakly dependent on Reynolds number and to be principally a function of the ratio of the rotational speed of the equator of the ball to the ...
Robert G. Watts, Ricardo Ferrer
openaire +3 more sources