Ballistic trajectory simulation method and flight simulation method for golf ball
First Claim
1. A ballistic trajectory simulation method for analyzing a ballistic trajectory when a golf ball having a plurality of dimples formed on the surface thereof is hit to fly making use of arithmetic operation by a computer, comprising the steps of:
- (A) setting, in a virtual space set by said computer, a golf ball model of a substantially spherical shape having a plurality of dimples formed on the surface thereof and an air current virtual region which surrounds the golf ball model;
(B) segmenting the air current virtual region into a large number of lattice segments such that the volume of the lattice segment gradually increases in a direction away from the ball surface of the golf ball model;
(C) setting a state wherein the golf ball model rotates at a predetermined number of rotations and an air current of a predetermined speed flows from forwardly of the golf ball model into the air current virtual region for a very short period of time and using the set state as a state wherein the golf ball rotates at the predetermined number of rotations and flies at the predetermined speed in the atmospheric air for the very short period of time to calculate the speed, direction and pressure of the air current formed in the air current virtual region for each of the lattice segments;
(D) integrating the speeds, directions and pressures of the air current calculated for the individual lattice segments to calculate a lift coefficient and a drag coefficient of the golf ball in the air current virtual region in which the air current is generated;
(E) calculating the flight distance, variation in height and speed of the ball after the golf ball flies for the very short period of time under the gravity from the lift coefficient and the drag coefficient and calculating the number of rotations of the ball after the flight for the very short period of time; and
(F) setting the calculated number of rotations and the calculated speed as the number of rotations and the speed after lapse of the very short period of time, respectively;
the operations of (C), (D), (E) and (F) being repeated so that the flight distance and the height of the ball after every lapse of the very short period of time after the ball is hit to fly until the ball drops to the ground are successively calculated to estimate the ballistic trajectory.
1 Assignment
0 Petitions
Accused Products
Abstract
A ballistic trajectory method for a golf ball is disclosed wherein a ballistic trajectory of a golf ball having a plurality of dimples formed on the surface thereof when the golf ball is hit to fly at an arbitrary number of rotations and an arbitrary initial speed can be estimated and ballistic trajectory and flight characteristics of the golf ball can be evaluated without depending upon experimental evaluation which is based on an actual model thereby to allow a golf ball to be developed efficiently. The ballistic trajectory of the golf ball when the golf ball is hit to fly is estimated by successively calculating the flight distance and the height of the ball after every lapse of a very short period of time after the ball is hit to fly until it drops to the ground making use of arithmetic operation by a computer.
-
Citations
12 Claims
-
1. A ballistic trajectory simulation method for analyzing a ballistic trajectory when a golf ball having a plurality of dimples formed on the surface thereof is hit to fly making use of arithmetic operation by a computer, comprising the steps of:
-
(A) setting, in a virtual space set by said computer, a golf ball model of a substantially spherical shape having a plurality of dimples formed on the surface thereof and an air current virtual region which surrounds the golf ball model; (B) segmenting the air current virtual region into a large number of lattice segments such that the volume of the lattice segment gradually increases in a direction away from the ball surface of the golf ball model; (C) setting a state wherein the golf ball model rotates at a predetermined number of rotations and an air current of a predetermined speed flows from forwardly of the golf ball model into the air current virtual region for a very short period of time and using the set state as a state wherein the golf ball rotates at the predetermined number of rotations and flies at the predetermined speed in the atmospheric air for the very short period of time to calculate the speed, direction and pressure of the air current formed in the air current virtual region for each of the lattice segments; (D) integrating the speeds, directions and pressures of the air current calculated for the individual lattice segments to calculate a lift coefficient and a drag coefficient of the golf ball in the air current virtual region in which the air current is generated; (E) calculating the flight distance, variation in height and speed of the ball after the golf ball flies for the very short period of time under the gravity from the lift coefficient and the drag coefficient and calculating the number of rotations of the ball after the flight for the very short period of time; and (F) setting the calculated number of rotations and the calculated speed as the number of rotations and the speed after lapse of the very short period of time, respectively; the operations of (C), (D), (E) and (F) being repeated so that the flight distance and the height of the ball after every lapse of the very short period of time after the ball is hit to fly until the ball drops to the ground are successively calculated to estimate the ballistic trajectory. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. A ballistic trajectory simulation method for analyzing a ballistic trajectory when a golf ball having a plurality of dimples formed on the surface thereof is hit to fly making use of arithmetic operation by a computer, comprising the steps of:
-
(A) setting, in a virtual space set by said computer, a golf ball model of a substantially spherical shape having a plurality of dimples formed on the surface thereof and an air current virtual region which surrounds the golf ball model; (B) segmenting the air current virtual region into a large number of lattice segments such that the volume of the lattice segment gradually increases in a direction away from the ball surface of the golf ball model; (C) setting a state wherein the golf ball model rotates at a predetermined number of rotations and an air current of a predetermined speed flows from forwardly of the golf ball model into the air current virtual region for a very short period of time and using the set state as a state wherein the golf ball rotates at the predetermined number of rotations and flies at the predetermined speed in the atmospheric air for the very short period of time to calculate the speed, direction and pressure of the air current formed in the air current virtual region for each of the lattice segments; (D) integrating the speeds, directions and pressures of the air current calculated for the individual lattice segments to calculate a lift coefficient and a drag coefficient of the golf ball in the air current virtual region in which the air current is generated; (D-1) repetitively carrying out the operations of (A) to (D) changing the number of rotations of the ball and the speed of the air current and mapping lift coefficients and drag coefficients of the golf ball at the number of rotations of the ball and the speeds of the air current obtained thereby to produce a reference map in advance; (D-2) deciding the lift coefficient and the drag coefficient at a predetermined number of rotations and a predetermined speed from the reference map; (E) calculating the flight distance, variation in height and speed of the ball after the golf ball flies for the very short period of time under the gravity from the lift coefficient and the drag coefficient and calculating the number of rotations of the ball after the flight for the very short period of time; and (F-1) setting the calculated number of rotations and the calculated speed as the speed of rotation and the speed after lapse of the very short period of time; the operations of (D-2), (E) and (F-1) being repeated so that the flight distance and the height of the ball after every lapse of the very short period of time after the ball is hit to fly until the ball drops to the ground are successively calculated to estimate the ballistic trajectory. - View Dependent Claims (8, 9, 10, 11)
-
-
12. A method of producing a reference map for use in a ballistic trajectory simulation method for analyzing a ballistic trajectory when a golf ball having a plurality of dimples formed on the surface thereof is hit to fly making use of arithmetic operation by a computer, the producing the reference map comprising the steps of:
-
calculating a lift coefficient and a drag coefficient corresponding to a speed and a rotational speed at each of a plurality of points at which the speed and the rotational speed are changed within a necessary range in advance with regard to the speed and a number of rotations of the golf ball necessary to simulate the ballistic trajectory of the ball; and mapping the lift coefficient and the drag coefficient of the golf ball at each of the numbers of rotations of the ball and each of the speeds of the air current determined by a calculation in a space which has an X axis of the speed, a Y axis of the number of rotations and a Z axis of at least one of the lift coefficient and the drag coefficient.
-
Specification