Measurements of forces on motorcycle sport model on wind tunnel

Abstract

This thesis presents a study of the aerodynamical behaviour of a sportive motorcycle in a wind tunnel. This analysis has been performed in the wind tunnel of the Mechanics and Aeronautics department of La Sapienza University of Rome. The first step has been the development of a reference overview in chapter 1 about the general features of wind tunnels and the typically measurements performed in the particular case of a motorcycle. Chapter 2 describes in great detail the present experimental set-up. In order to carry out these measurements in the wind tunnel, a dynamometric balance has been used. A very important part on the development of this project is the calibration of this balance in order to get a high reliability on the results. This calibration process is explained in great detail in chapter 3. The main problem that has arisen with the calibration of the balance is the presence of friction, which can be solved using some small spheres in order to minimize this effect, as it is explained in chapter 3. Finally, chapter 4 includes the measurements performed in the wind tunnel and the analysis and conclusions derived from the results. These measurements have been performed for different speeds of wind from 0 to 30 m/s to check the evolution of the values of the dimensionless aerodynamic coefficients. Moreover, to study the behaviour of the motorcycle on a curve or in the case of lateral wind, the measurements have been performed with different yawing angles from -30º to +30º every 10º. This study of positive and negative angles also allows checking if the results fit the theoretical symmetry of the model, although the final conclusion will be that this symmetry is not achieved exactly due to the complexity of the aerodynamical studies.------------------------------------------------------------------------------------------------------------------------------

El siguiente trabajo presenta un análisis del comportamiento de un modelo a escala 1:10 de una motocicleta deportiva, en concreto, la Yamaha M1. El estudio se ha llevado a cabo en las instalaciones del departamento de mecánica y aeronáutica de la universidad La Sapienza de Roma, en el cual se haya el túnel de viento donde se han realizado las medidas.