Results 11 to 20 of about 72,003 (271)

Thickness effect of Naca foils on hydrodynamic global parameters, boundary layer states and stall establishment [PDF]

, 2010
The present study investigates experimentally the hydrodynamic behavior of 2D NACA (15, 25, 35%) symmetric hydrofoils at Reynolds number 0.5 106 . A particular attention is paid on the hysteretic behavior at static stall angle and a detailed cartography
Billard, Jean-Yves, Djeridi, Henda, Prothin, Sebastien, Sarraf, Christophe   +3 more
core   +14 more sources

A vorticity-based criterion to characterise leading edge dynamic stall onset

Journal of Fluid Mechanics, 2022
We propose a more conservative, physically-intuitive criterion, namely, the boundary enstrophy flux ($BEF$), to characterise leading-edge-type dynamic stall onset in incompressible flows.
S. Sudharsan, B. Ganapathysubramanian, A. Sharma   +2 more
semanticscholar   +1 more source

Criteria for dynamic stall onset and vortex shedding in low-Reynolds-number flows [PDF]

Journal of Fluid Mechanics
Dynamic stall at low Reynolds numbers, $Re \sim O(10^4)$, exhibits complex flow physics with co-existing laminar, transitional and turbulent flow regions.
S. Sudharsan, Anupam Sharma
semanticscholar   +1 more source

Bifurcation scenario for a two-dimensional static airfoil exhibiting trailing edge stall

Journal of Fluid Mechanics, 2021
We numerically investigate stalling flow around a static airfoil at high Reynolds numbers using the Reynolds-averaged Navier–Stokes equations (RANS) closed with the Spalart–Allmaras turbulence model.
Denis Busquet, O. Marquet, F. Richez, M. Juniper, D. Sipp   +4 more
semanticscholar   +1 more source

Construction of reduced-order models for fluid flows using deep feedforward neural networks [PDF]

Journal of Fluid Mechanics, 2019
We present a numerical methodology for construction of reduced-order models (ROMs) of fluid flows through the combination of flow modal decomposition and regression analysis.
Hugo F. S. Lui, W. Wolf
semanticscholar   +1 more source

Comparative study of transition models for high-angle-of-attack behavior [PDF]

, 2019
This paper considers transition modeling for the flow over small unmanned aerial vehicles with a span of around 1 m. Such flows are characterized by very low values of turbulence intensity, and the main cause for transition corresponds to flow separation.
Degroote, Joris, Vierendeels, Jan, Wauters, Jolan   +2 more
core   +1 more source

An Explanation for the Existence of Stall Hysteresis

Fluid Mechanics
An explanation of the mechanism for the difference in angle for separation and reattachment during stall on airfoils via potential flow and stall-prediction theories is proposed as follows: the reattachment angle of any given airfoil is the stall angle ...
W. Ii
semanticscholar   +1 more source

Trajectory optimization of a flapping-wing robot in a wind field

工程科学学报
Owing to wave obstruction, the speed of the horizontal wind field decreases as it approaches the sea surface. Consequently, the wind field that increases with height is referred to as a gradient wind field.
Xiaoyang WU, Zhiguo ZHANG, Wei HE, Jingyan QIN, Junhai ZHANG, Tingting MENG   +5 more
doaj   +1 more source

Aerofoil behaviour at high angles of attack and at Reynolds numbers appropriate for small wind turbines [PDF]

, 2014
The aerodynamic characteristics of a NACA0018 aerofoil have been investigated experimentally for incidence angles ranging from 0° to 180° in closed-jet and open-jet wind tunnels with different blockage coefficients at Reynolds numbers from 60,000 to 140 ...
Berson, Arganthaël, Dominy, Robert, Du, Longhuan   +2 more
core   +2 more sources

Unsteady aerodynamic effects in small-amplitude pitch oscillations of an airfoil

, 2018
High-fidelity wall-resolved large-eddy simulations (LES) are utilized to investigate the flow-physics of small-amplitude pitch oscillations of an airfoil at Re = 100,000.
Hanifi, Ardeshir, Henningson, Dan S., Negi, Prabal S., Schlatter, Philipp, Vinuesa, Ricardo   +4 more
core   +1 more source