Aerodynamics of fixed and rotating spoked cycling wheels

Karabelas, SJ; Markatos, NC

dc.contributor.author	Karabelas, SJ	en
dc.contributor.author	Markatos, NC	en
dc.date.accessioned	2014-03-01T02:07:36Z
dc.date.available	2014-03-01T02:07:36Z
dc.date.issued	2012	en
dc.identifier.issn	00982202	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/29589
dc.subject	cycling wheels	en
dc.subject	ground effect	en
dc.subject	Magnus effect	en
dc.subject	spinning cylinder	en
dc.subject	turbulence	en
dc.subject.other	Aerodynamic performance	en
dc.subject.other	Constant angular velocity	en
dc.subject.other	Cross wind	en
dc.subject.other	Drag forces	en
dc.subject.other	Effects of rotation	en
dc.subject.other	Experimental measurements	en
dc.subject.other	Free-stream	en
dc.subject.other	Magnus effect	en
dc.subject.other	Nonstationary	en
dc.subject.other	Numerical investigations	en
dc.subject.other	Numerical results	en
dc.subject.other	Rotational speed	en
dc.subject.other	Side force	en
dc.subject.other	Vertical force	en
dc.subject.other	Yaw angles	en
dc.subject.other	Yaw moment	en
dc.subject.other	Drag	en
dc.subject.other	Ground effect	en
dc.subject.other	Rotation	en
dc.subject.other	Rotors	en
dc.subject.other	Turbulence	en
dc.subject.other	Vehicles	en
dc.subject.other	Wheels	en
dc.title	Aerodynamics of fixed and rotating spoked cycling wheels	en
heal.type	journalArticle	en
heal.identifier.primary	10.1115/1.4005691	en
heal.identifier.secondary	http://dx.doi.org/10.1115/1.4005691	en
heal.identifier.secondary	011102	en
heal.publicationDate	2012	en
heal.abstract	The performance of a semiracing spoked wheel is numerically and experimentally studied at full size in a wind tunnel. The numerical investigation is divided into two parts. In the first part, the wheel is considered to be fixed (no rotation) and the numerical results are compared to the experimental measurements. The flow past the wheel is treated as stationary and turbulent. The effects of cross wind and the wheel's speed on the drag, side force, and yaw moment are investigated. Numerical results are presented via diagrams and plots at various yaw angles. Both the measurements and predictions agree quite well and they show a considerable increase in the yaw moment and side force at medium and high yaw angles. The axial drag force initially increases with yaw angle (up to 7.5 deg) and eventually decreases. Ground effects did not affect the overall loads, except for the vertical force at high yaw angles. In the second part, the effects of rotation have been taken into account. The wheel rotates at constant angular velocities and the flow is modeled as nonstationary and turbulent. The aerodynamic performance of the wheel is strongly affected by the rotational speed. In most of the cases, as the latter parameter increases, the loads nonlinearly increase. The rotation generates asymmetrical loading, since the flow is accelerated in one side and decelerated in the other (the Magnus effect). A vertical force is produced, which is dependent on the ratio of the rotational to the free-stream speed. Moreover, in an attempt to assess the effects of the number of spokes to the aerodynamic performance, two other models with 8 and 32 spokes have been numerically tested and compared to the original one (16 spokes). The results revealed, as expected, an increase in the axial drag and vertical force with the number of spokes. © 2012 American Society of Mechanical Engineers.	en
heal.journalName	Journal of Fluids Engineering, Transactions of the ASME	en
dc.identifier.doi	10.1115/1.4005691	en
dc.identifier.volume	134	en
dc.identifier.issue	1	en