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 a cricket ball
Abstract This paper describes experiments performed on stationary and rotating cricket balls to determine the aerodynamic forces acting on the ball over a range of bowling speeds and seam angles. Lift, drag and side forces were measured directly and it was found they exhibited magnitudes in the order of 1.4, 1 and 0.4 N, respectively, for the stationary ball. At air velocities above 20 m/s, the lift force increased with increasing air speed being weakly influenced by the vertical seam angle. At 10 m/s air speed, the side force began to increase steadily with air speed for seam angles up to 70°. At 80° the side force direction reversed due to the sudden movement of the separation point on the surface of the ball. Roughening one side of the ball increased the side force but delayed its reversal at 80° seam angle until a marginally higher velocity was reached. When top spin was applied to the smooth ball, the lift force increased almost linearly in the negative direction but there was no resultant side force. When a roughened ball was spun, the negative lift force was constant at all air speeds over a range of rotational speeds. The development of the measured forces are discussed in terms of boundary layer flow and Magnus effect.
Frequency selective surface design for blinds applications
In this paper, the reconfigurable blind structure with frequency selective surfaces(FSS) for the building applications are presented. Frequency transmission characteristics for different angles of the proposed blind-FSSs are investigated and verified through simulation and measurement. The simulation results show that we can implement the reconfigurable blind-FSS for multiband wireless applications. To verify the proposed paper, two kinds of blind-FSSs, crossed dipole FSS and circular ring FSS are fabricated and measurements are performed for different angles. The proposed structure in this paper which is very simple, can be easily applied to any planar surface for wireless security applications at low cost.