ABSTRACT
Reverse swing is generally achieved when the airflow becomes turbulent on both sides of the ball. Here the turbulent airflow at sides separates earlier on one side than the other. The phenomenon usually occurs with a ball that is bowled fast. It is not clear where the limits of velocity exist for this type of swing. A comprehensive study is required to answer this question. In reverse swing, unlike conventional swing, the ball deviates toward the rough side of the ball. Usually, any swing makes difficult for the batsman to hit the ball with his bat and guard the stamps. Traditionally reverse swing occurs when one half of the ball is has been naturally worn significantly. In most cricket matches, the phenomenon of reverse swing occurs after 40 or more overs (one over consists of a set of six bowled balls). The mechanism for a reverse swing is complex and still not fully understood due to the degree of ball’s surface roughness and required seam alignment angles with the mean direction of the flight. Although, some studies by Mehta (1985, 2000), Mehta & Wood (2000), Barrett & Wood (1996), Wilkinson (1997) and Barton (1982) were conducted to understand the aerodynamics of cricket ball, a comprehensive study to understand the gamut of complex aerodynamic behaviour resulting a wide range of swing under a wide range of wind conditions, relative roughness, seam orientations and seam prominence is yet to be conducted. Therefore, a large research project has been undertaken in the School of Aerospace, Mechanical and Manufacturing Engineering, RMIT University to understand the overall aerodynamic behaviour of the cricket ball both experimentally as well computationally. The work presented here is a part of this large research project. In order to understand the general behaviour of the airflow around a cricket ball, a large cricket ball (450 mm in diameter) was
constructed to visualise airflow using smoke trails. Three brands of First-Class cricket balls were used (see Figure 2) including a One-Day International ball (see Figure 3) were used to measure the aerodynamic properties under range of wind and spin conditions.
