GOLF BALL TRAJECTORY SIMULATION METHOD
First Claim
1. A golf ball trajectory simulation method that employs arithmetic operations executed by a computer to analyze and estimate a trajectory of a golf ball having a plurality of dimples on a surface thereof when the ball is launched into flight, comprising the steps of:
- (A) generating a grid within a virtual airflow space (field) where the ball is to be launched;
(B) setting up within the virtual airflow space (field) a substantially spherical golf ball model having a plurality of dimples formed on a surface thereof;
(C) dividing the grid into cells in such a way as to make the grid near the golf ball model finer than the grid within the virtual space (field) and to have the grid gradually increase in size in a direction leading away from the surface of the ball model;
(D) setting a weight for the golf ball model;
(E) applying initial conditions (initial velocity, launch angle, spin rate) to the golf ball model;
(F) initiating movement of the golf ball model under the initial conditions, regenerating in a region of movement the grid near the ball in such a way as to follow the movement of the ball model without disturbing the originally set grid size, and restoring the grid after the ball has passed therethrough to the grid within the virtual airflow space (field);
(G) calculating a lift coefficient and a drag coefficient for the golf ball in flight within the virtual airflow space (field) by integrating an air stream velocity, direction and pressure calculated in each grid cell within the virtual airflow space (field); and
(H) calculating a flight distance and a left-to-right dispersion for the golf ball from launch until landing by calculating a change in height, a change in lateral direction, a change in velocity and a change in spin rate for the golf ball during flight.
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Abstract
The invention is directed at a golf ball trajectory simulation method that employs arithmetic operations executed by a computer to analyze a trajectory of a golf ball having a plurality of dimples on a surface thereof when the ball is launched into flight. The trajectory of the ball is estimated by setting up a golf ball model within a virtual airflow space (field) where a grid has been generated; setting a weight for the golf ball model and applying initial conditions (initial velocity, launch angle, spin rate) to the ball model so as to cause the model to fly within the virtual airflow space (field); calculating a lift coefficient and a drag coefficient for the golf ball from an air stream velocity, direction and pressure calculated in each grid cell; and calculating a flight distance and left-to-right dispersion for the golf ball from launch until landing by calculating a change in height, a change in lateral direction, a change in velocity and a change in spin rate for the golf ball during flight.
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Citations
8 Claims
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1. A golf ball trajectory simulation method that employs arithmetic operations executed by a computer to analyze and estimate a trajectory of a golf ball having a plurality of dimples on a surface thereof when the ball is launched into flight, comprising the steps of:
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(A) generating a grid within a virtual airflow space (field) where the ball is to be launched; (B) setting up within the virtual airflow space (field) a substantially spherical golf ball model having a plurality of dimples formed on a surface thereof; (C) dividing the grid into cells in such a way as to make the grid near the golf ball model finer than the grid within the virtual space (field) and to have the grid gradually increase in size in a direction leading away from the surface of the ball model; (D) setting a weight for the golf ball model; (E) applying initial conditions (initial velocity, launch angle, spin rate) to the golf ball model; (F) initiating movement of the golf ball model under the initial conditions, regenerating in a region of movement the grid near the ball in such a way as to follow the movement of the ball model without disturbing the originally set grid size, and restoring the grid after the ball has passed therethrough to the grid within the virtual airflow space (field); (G) calculating a lift coefficient and a drag coefficient for the golf ball in flight within the virtual airflow space (field) by integrating an air stream velocity, direction and pressure calculated in each grid cell within the virtual airflow space (field); and (H) calculating a flight distance and a left-to-right dispersion for the golf ball from launch until landing by calculating a change in height, a change in lateral direction, a change in velocity and a change in spin rate for the golf ball during flight. - View Dependent Claims (2, 3, 4)
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5. A golf ball trajectory simulation method that employs arithmetic operations executed by a computer to analyze and estimate a trajectory of a golf ball having a plurality of dimples on a surface thereof when the ball is launched into flight, comprising the steps of:
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(A) generating a grid within a virtual airflow space (field) where the ball is to be launched; (B) setting up within the virtual airflow space (field) a substantially spherical golf ball model having a plurality of dimples formed on a surface thereof; (C) dividing the grid into cells in such a way as to make the grid near the golf ball model finer than the grid within the virtual space (field) and to have the grid gradually increase in size in a direction leading away from the surface of the ball model; (D) setting a weight for the golf ball model; (D-2) setting up within the virtual airflow space a state wherein an air stream of a given velocity flows into the golf ball model; (E) applying initial conditions (initial velocity, launch angle, spin rate) to the golf ball model; (F) initiating movement of the golf ball model under the initial conditions, regenerating in a region of movement the grid near the ball in such a way as to follow the movement of the ball model without disturbing the originally set grid size, and restoring the grid after the ball has passed therethrough to the grid within the virtual airflow space (field); (G) calculating a lift coefficient and a drag coefficient for the golf ball in flight within the virtual airflow space (field) by integrating an air stream velocity, direction and pressure calculated in each grid cell within the virtual airflow space (field); and (H) calculating a flight distance and a left-to-right dispersion for the golf ball from launch until landing by calculating a change in height, a change in lateral direction, a change in velocity and a change in spin rate for the golf ball during flight. - View Dependent Claims (6, 7, 8)
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Specification