An investigation of the aerodynamics of racing motorcycles

Ellery, MK

Abstract

The purpose of this thesis is to present a study on
motorcycle aerodynamics with particular regard to the
performance characteristics of faired and unfaired types in
use today for road racing and speed record attempts. To
achieve this, a wind tunnel procedure for the testing of
scale models was developed with emphasis on the problems involved in obtaining valid data from large model-to-tunnel area blockage ratios, (approximately 15'%).
Following a review of the results, which included six aerodynamic force and moment coefficients and their
variation with Reynolds number and yaw angle, a programme of drag reduction was pursued which approached the problem from two directions: firstly, by using simple bolt-on devices for conventional fairings, designed so as to obviate the need for major machine modifications and secondly, by a complete redesign of the motorcycle.� The latter involved the use of more efficient aerodynamic shapes and also achieved a reduction in frontal area without compromising rider comfort.
The final result was a machine which would provide
greatly enhanced racing performance through a drag
reduction of approximately 40% and also lend itself to the
incorporation of radical primary and secondary safety
features, beneficial both an the track and public roads.
Preliminary studies into a computational flow simulation
as a first stage to the full prediction of fairing pressure
distribution are also included. The techniques explored
attempted to retain a reasonable accuracy of result without
recourse to excessive computer power or complicated
calculations. This was achieved successfully with the
simple models considered, despite the highly separated nature of the simulated flow.

Citation

Ellery, M. An investigation of the aerodynamics of racing motorcycles. (Thesis). University of Salford

• Thesis Type: Thesis
• Deposit Date: Jul 13, 2017
• Publisher URL: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.353979
• Related Public URLs: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.353979
• Award Date: Apr 1, 1985