Title: "Analysis of Drag Coefficient of Cannonballs Colliding into Water Surface"

Page(s): 76 - 79
Authors: H. S. BANG   , H. S. LEE    , S. H. PARK   , W. C. CHOI    , Y. K. KIM   


When a cannonball collides onto water, it can ricochet several times when a normal force generated larger is than sum of the weight and inertia force. The impact occurring during collision is influenced by the drag coefficient, lift coefficient, sea wave angle, cannonball speed, initial launch angle, etc. In order to determine the moving path of the cannonball, an analysis is done to calculate the position and velocity of the cannonball and the force acting on the cannonball using a finite element method. In this study, the drag and lift coefficients are calculated through experiment and energy equations. It is found that a high entry angle when collide into water surface results the high drag and lift coefficients, and that the ricocheting distance varies depending on the sea wave angle, launch angle and launch height.