@article{Venning2017,
title = {The nature of the vortical structures in the near wake of the Ahmed body},
author = {James A Venning and David {Lo Jacono} and David Burton and Mark C Thompson and John Sheridan},
url = {https://jamesvenning.net/wp-content/uploads/2015/11/Venning-et-al.-2017-The-nature-of-the-vortical-structures-in-the-near-wake-of-the-Ahmed-body.pdf},
doi = {10.1177/0954407017690683},
issn = {09544070},
year = {2017},
date = {2017-01-01},
journal = {Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering},
volume = {231},
number = {9},
pages = {1239--1244},
abstract = {This study presents the results from high-spatial-resolution water-channel velocity-field measurements behind an Ahmed body with 25° rear slant angle. The Ahmed body represents a simplified generic model of a hatchback automobile that has been widely used to study near-wake flow dynamics. The results help clarify the unresolved question of whether the time-mean near-wake flow structure is topologically equivalent to a toroidal vortex or better described by a pair of horizontally aligned horseshoe vortices, with their legs pointing downstream. The velocimetry data presented allows the tracking of the vortical structures throughout the near wake through a set of orthogonal planes, as well as the measurement of their circulation. The spanwise vortices that form as the flow separates from the top and bottom rear edges are shown to tilt downstream at the sides of the body, while no evidence is found of a time-mean attached toroidal vortex, at least for the Reynolds number (based on the square root of the frontal area) of R e FA ∼ 30, 000 under consideration.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Crouch2016,
title = {A comparison of the wake structures of scale and full-scale pedalling cycling models},
author = {T N N Crouch and D Burton and J A A Venning and M C C Thompson and N A T A T Brown and J Sheridan},
url = {https://jamesvenning.net/wp-content/uploads/2020/04/1-s2.0-S1877705816306294-main.pdf},
doi = {10.1016/j.proeng.2016.06.182},
issn = {1877-7058},
year = {2016},
date = {2016-01-01},
journal = {Procedia Engineering},
volume = {147},
pages = {13--19},
publisher = {The Author(s)},
abstract = {This paper presents a novel approach to better understand the unsteady aerodynamics associated with a dynamically pedalling cyclist. Using high resolution Particle Image Velocimetry (PIV) in a water channel, the large-scale wake structure is analysed for various phases of the crank cycle of a 1:4.5 scale-model cyclist/bicycle under both static and pedalling conditions. Both quasi-steady and dynamic pedalling leg results are compared with detailed velocity field surveys made in the wake of a full-scale pedalling cyclist mannequin of similar geometry and position in a wind tunnel. A time-averaged and phase-averaged analysis of the various flow regimes that occur throughout the pedal stroke shows good agreement between scale-model and full-scale mannequin investigations. This highlights the robustness of the formation of the primary wake flow structures when subjected to varying Reynolds number, bicycle/rider geometry and quasi-steady/dynamic pedalling conditions.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Huang2015,
title = {Vortex separation and interaction in the wake of inclined trapezoidal plates},
author = {Y Huang and J Venning and M C Thompson and J Sheridan},
url = {https://jamesvenning.net/wp-content/uploads/2015/11/JFM_Vortex_separation_and_interaction_in_the_wake_of_inclined_trapezoidal_plates.pdf},
doi = {10.1017/jfm.2015.160},
year = {2015},
date = {2015-01-01},
journal = {Journal of Fluid Mechanics},
volume = {771},
pages = {341--369},
publisher = {Cambridge University Press},
abstract = {Full three-dimensional numerical simulations are employed to investigate the flows over inclined trapezoidal low-aspect-ratio plates at low Reynolds numbers, aiming to understand the unsteadiness induced by the interaction between the trailing vortical wake structures originating from the swept edges, and those from the leading and trailing edges. The flows past eighteen different plate geometries in three broad sets are simulated to study the influence of aspect ratio, taper angle and angle of attack on the wake vortices and the force coefficients. Both taper ratio and angle of attack of plates with the same area are found to have a broadly predictable influence on the wake stability and asymptotic forces. Smaller taper ratios result in lower maximum lift, while an increase in the angle of attack results in a reduction in the differences in maximum lift. Two distinct modes of periodic unsteady flow with significant differences in frequency are observed. The corresponding vortex-shedding mechanisms are analysed with the aid of Q-criterion isosurfaces and streamlines. A low wake frequency is observed at small taper angles when there is relative independence between the von Kármán vortices originating from the leading and trailing edges, and weak swept-edge vortices. The dominant Strouhal number in this state is approximately 0.09. When the taper angle or angle of attack increases, the flows over the swept edges form stronger trailing vortex structures which interact strongly with the leading-edge vortices, combining to produce a regular stream of vortex loops shed into the wake. In this regime, the dominant Strouhal number increases to approximately 0.14-0.18. Higher Reynolds numbers and/or angles of attack result in a loss of centre plane reflection symmetry in the wake. The aerodynamic forces have been quantified as a function of the problem parameters and plate geometry. textcopyright 2015 Cambridge University Press.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Venning2015,
title = {The effect of aspect ratio on the wake of the Ahmed body},
author = {J Venning and D {Lo Jacono} and D Burton and M C Thompson and J Sheridan},
url = {https://jamesvenning.net/wp-content/uploads/2015/11/EXIF_The_effect_of_aspect_ratio_on_the_wake_of_the_Ahmed_body.pdf},
doi = {10.1007/s00348-015-1996-5},
issn = {1432-1114},
year = {2015},
date = {2015-01-01},
journal = {Experiments in Fluids},
volume = {56},
number = {126},
publisher = {Springer Berlin Heidelberg},
abstract = {This paper seeks to further elucidate the wake of the Ahmed body by investigating how the time-averaged flow structures vary with frontal aspect ratio. High-resolution particle image velocimetry results are provided for eight different width Ahmed geometries at Re√FA = 3 × 10^4 . It is shown that the narrower the body, the greater the downwash over the back slant, meaning the flow remains more attached. At a critical aspect ratio (AR = 1.9), the flow downstream changes. The separation over the back slant is shown to be affected by the AR, and this in turn has a significant effect on the circulation in the c-pillar vortices.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}