Simulation of Aerodynamics of the Cricket Ball with Soil Conditions of the Pitch
This paper describes Simulation of Aerodynamics of the Cricket Ball using digitalanlyzer version1.2 .The results show the deviation of ball depend on aerodynamics properties. This paper also shows that different types of ball have different observed co efficient with different types of surface. This paper will help for referring decision to third umpire in LBW.
Aerodynamics of Sports Balls
Research data on the aerodynamic behavior of baseballs and cricket and golf balls are summarized. Cricket balls and baseballs are roughly the same size and mass but have different stitch patterns. Both are thrown to follow paths that avoid a batter's swing, paths that can curve if aerodynamic forces on the balls' surfaces are asymmetric. Smoke tracer wind tunnel tests and pressure taps have revealed that the unbalanced side forces are induced by tripping the boundary layer on the seam side and producing turbulence. More particularly, the greater pressures are perpendicular to the seam plane and only appear when the balls travel at velocities high enough so that the roughness length matches the seam heigh. The side forces, once tripped, will increase with spin velocity up to a cut-off point. The enhanced lift coefficient is produced by the Magnus effect. The more complex stitching on a baseball permits greater variations in the flight path curve and, in the case of a knuckleball, the unsteady flow effects. For golf balls, the dimples trip the boundary layer and the high spin rate produces a lift coefficient maximum of 0.5, compared to a baseball's maximum of 0.3. Thus, a golf ball travels far enough for gravitational forces to become important.
Research on aerodynamic noise around automobiles
Abstract Along with improved quietness in vehicles in recent years, aerodynamic noise reduction has been demanded strongly. Actions concerning the noise generating source analysis are important. To study the direction for aerodynamic noise reduction, we have theoretically analyzed the characteristics of the sources of aerodynamic noise. As a result, we have succeeded in clarifying the relationships between the flow patterns and noise properties; the resulting aerodynamic noise reduction has been confirmed both in wind tunnel test and on road test.