Results 21 to 30 of about 1,827 (197)
Deep‐time invention and hydrodynamic convergences through amniote flipper evolution
The Anatomical Record, Volume 306, Issue 6, Page 1323-1355, June 2023., 2023 Abstract The diapsid plesiosaurs were pelagic and inhabited the oceans from the Triassic to the Cretaceous. A key evolutionary character of plesiosaurs is the four wing‐like flippers. While it is mostly accepted that plesiosaurs were underwater fliers like marine turtles, penguins, and maybe whales, other swimming styles have been suggested in the past.
Anna Krahl, Ingmar Werneburg
wiley +1 more source
Beltrami fields and knotted vortex structures in incompressible fluid flows
Bulletin of the London Mathematical Society, Volume 55, Issue 3, Page 1059-1103, June 2023., 2023 Abstract This paper gives a survey on recent results about the existence of knotted vortex structures in incompressible fluids. This includes the proof of Lord Kelvin's conjecture on the existence of knotted vortex tubes in steady Euler flows and a new probabilistic approach to address Arnold's speculation that typical Beltrami fields should exhibit ...
Alberto Enciso, Daniel Peralta‐Salas
wiley +1 more source
Ship waves in rivers: Environmental criteria and analysis methods for measurements
River Research and Applications, Volume 39, Issue 4, Page 629-647, May 2023., 2023 Abstract A literature review shows that the most important physical quantities determining environmental impact of ship waves in a waterway are the fluid velocities, maximum and minimum water levels, and size of drawdown events. Fluid velocity can vary strongly in the vertical so that the usual measurements at a single point are not enough unless made ...
John D. Fenton +3 more
wiley +1 more source
Role of Shape and Kinematics in the Hydrodynamics of a Fish-like Oscillating Hydrofoil
Journal of Marine Science and Engineering, 2023 In the present two-dimensional numerical study, we investigate the roles of geometrical parameters of a hydrofoil (shape/curvature of the leading and trailing edges and thickness) and kinematic parameters (phase difference between heave and pitch (ϕ)) on
Siddharth Gupta +4 more
doaj +1 more source
Lake dynamics in an Early Jurassic desert: Evidence from the Clarens Formation in southern Africa
Sedimentology, Volume 70, Issue 3, Page 865-894, April 2023., 2023 ABSTRACT Interdune deposits are sensitive to climatic fluctuations and ancient interdune lacustrine systems can reveal the drivers of erg dynamics through time and space. This southern African study details the dynamics of interdune deposition in a vast ancient desert system that was active over Pangaea in the Middle Mesozoic and formed part of one of ...
Howard V. Head, Emese M. Bordy
wiley +1 more source
Study of Underwater and Wave Gliders on the Basis of Simplified Mathematical Models
Applied Sciences, 2022 Both underwater and wave gliders are known as autonomous unmanned energy-saving vehicles which have recently found applications for monitoring the world ocean.
Kirill Rozhdestvensky
doaj +1 more source
Optimal Design and Numerical Simulation on Fish-Like Flexible Hydrofoil Propeller
Polish Maritime Research, 2016 Hydrofoil is widely used in underwater vehicle for the excellent hydrodynamic characteristics. Currently, researches are mostly about the rigid hydrofoil while the flexible hydrofoil, like the caudal fin, has not been studied adequately.
Xue Gang +6 more
doaj +1 more source
Pressure Characteristics and Cavitation on an Oscillating Hydrofoil
Journal of the Society of Naval Architects of Japan, 1972 Unsteady cavitation that results from the non-uniformity of the flow field renders evil influences on marine propellers. It has been a general experiment for the investigation on such problems to observe unsteady cavitation in a flow field analogous to a wake pattern.
Hideaki Miyata +2 more
openaire +2 more sources
Observations of Shock Waves in Cloud Cavitation [PDF]
, 1998 This paper describes an investigation of the dynamics and acoustics of cloud cavitation, the structures which are often formed by the periodic breakup and collapse of a sheet or vortex cavity.
Brennen, C. E. +2 more
core +1 more source
Hydrodynamic Analysis of a Flopping NACA0012 Hydrofoil and Dolphin Fish-Like Model [PDF]
Journal of Applied Fluid MechanicsImitating Dolphin fish-like movement is productive method for enhancing their hydrodynamic capabilities. This work aims to analyze and understand the oscillations of tail fluke of Dolphin, which can be used as a propulsive mechanism for underwater fish ...
T. Prabu +2 more
doaj +1 more source