An investigation of the aerodynamics of racing motorcycles

The purpose of this thesis is to present a study onmotorcycle aerodynamics with particular regard to theperformance characteristics of faired and unfaired types inuse today for road racing and speed record attempts. Toachieve this, a wind tunnel procedure for the testing ofscale 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 theirvariation 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 providegreatly enhanced racing performance through a dragreduction of approximately 40% and also lend itself to theincorporation of radical primary and secondary safetyfeatures, beneficial both an the track and public roads.Preliminary studies into a computational flow simulationas a first stage to the full prediction of fairing pressuredistribution are also included. The techniques exploredattempted to retain a reasonable accuracy of result withoutrecourse to excessive computer power or complicatedcalculations. This was achieved successfully with thesimple models considered, despite the highly separated nature of the simulated flow.

Level dc:type.qualificationlevel

Doctoral (Level 8)

Year dc:date.issued

1985

Author dc:creator

• Ellery, MK

Language dc:language

en

Identifier

oai:salford-repository.worktribe.com:1389768

OAI identifier oai:identifier

oai:salford-repository.worktribe.com:1389768