In this blog post, we will look at the principles of the flight of a golf ball from a scientific perspective and find out why flow control and Bernoulli’s theorem are important.
The secrets of a golf ball
If you look closely at a golf ball, you will see that it is not a smooth sphere, but that it is surrounded by small grooves. These are called dimples. Many people know that dimples help golf balls fly farther. However, the scientific principles behind how dimples affect the flight of a ball may be unclear. To understand this, we must first learn about the academic concept of flow control. Flow control is the study of how to regulate and control the flow of fluids, and its principles can be found in our daily lives through various engineering applications.
What is flow?
First, it is necessary to explain the word “flow.” The state of matter can be divided into solid, liquid, and gas, and among these, fluid refers to liquid and gas. Flow refers to the phenomenon of these fluids flowing. While solids have fixed shapes and forms, fluids flow freely and do not have a constant shape. To make it easier to understand, let’s think of the students on the playground. Solids maintain a fixed shape, like the students standing in a row, while liquids are like the students who move freely around the playground. Gases flow freely and are almost invisible, like the students who quickly leave the playground after school.
After understanding the state of the fluid, we can think about how to control the flow of the fluid. While the movement of solids can be easily seen with the naked eye, the flow of liquids or gases cannot. In particular, it is difficult to directly observe the flow of gases because they are invisible to the naked eye. The key to flow control is to study the movement, shape, and characteristics of these invisible fluids and to consider how to use them in real life.
Control of the flow of a golf ball and the role of dimples
When a golfer hits a golf ball with a driver and the ball flies into the air, various physical forces begin to act. Gravity acts in the direction of the ground, and air resistance acts in the opposite direction to the direction the ball is flying. What is important here is that the ball does not simply fly in a straight line, but that it is given a spin. In particular, a golf ball hit with a driver is given a spin called “backspin,” which greatly affects the ball’s flight trajectory.
A golf ball with backspin interacts with the air depending on the direction of the spin. Due to the viscosity of the air, the air flowing around the ball is subjected to a force in the same direction as the direction of rotation. The viscosity of the air is very weak, but when the ball rotates quickly, the effect becomes large enough to change the trajectory of the ball. Like a baseball changeup or a banana kick in soccer, golf balls are also used to fly far using the physical principle of this rotation.
Bernoulli’s theorem and the flight of a golf ball
The backspin on a golf ball causes different air currents on the bottom and top of the ball. On the bottom, air is pushed in the same direction as the ball’s movement, while on the top, it is pushed in the opposite direction. This difference causes the bottom of the ball to slow down and increase in pressure, while the top of the ball speeds up and decreases in pressure. This pressure difference causes the golf ball to receive lift force and stay in the air longer. This is one of the important reasons why golf balls can fly farther.
Bernoulli’s theorem is the physical law that explains this phenomenon. This theorem shows the relationship between the flow velocity, pressure, and potential energy of a fluid, and it shows that the faster the flow, the lower the pressure, and the slower the flow, the higher the pressure. Simply put, when a car suddenly slows down on the road, the distance between cars narrows and the pressure increases, and the same is true for fluids: when the velocity decreases, the pressure increases.
Engineering effects of dimples
Now let’s take a look at why dimples play an important role in sending golf balls far. A ball with dimples is more likely to receive stronger backspin than a smooth ball without dimples, and as a result, it can generate greater lift. Dimples reduce friction with the air and help to change the airflow around the ball to maximize lift. Therefore, dimpled golf balls can stay in the air longer, which increases the distance they can travel.
The flight characteristics of the ball can vary depending on the shape, size, and arrangement of the dimples. According to research to date, the ideal structure of dimples has not yet been fully elucidated, but research on flow control to optimize them is ongoing. Such research is playing an important role in improving aerodynamic performance in various fields, such as aircraft, ships, and automobiles, as well as golf balls.
The future of flow control and its engineering applications
Flow control is not limited to golf balls. Flow control technology has a significant impact on various industries, including the efficient flight of aircraft, fuel savings for ships, and noise reduction for automobiles. In particular, in the aerospace industry, flow control is contributing greatly to maximizing aircraft performance and reducing fuel consumption. This development of flow control will play an important role in helping us develop better technology and enable efficient use of resources.
In the future, flow control will lead to more scientific discoveries and engineering innovations, and will make our lives more convenient through various applications, not only in sports equipment such as golf balls, but also in our daily lives. Understanding and controlling the flow of air and fluids is one of the most important academic challenges for human creativity and technological development.
