Throwing flat pebbles on the surface of the water looks like child's play only at first glance. Researchers at the University of Utah tried to understand the scientific background of this entertainment. As a result, they identified several physical patterns in the interaction of water with various objects, which can find application in the field of marine technology.
Back in the 18th century, the famous English admiral Nelson discovered that artillery shells "jumping" on water fly much farther. A more famous case is associated with the time of the Second World War, when the bouncing bomb was invented by engineer Barnes Wallace, with which the British Air Force destroyed dams in Germany.
At first glance, the intermittent movement of an object on the surface of the water seems to be quite simple. However, in reality we are talking about the complex interaction of the aquatic environment with the shape of an object, its size, material, surface texture, friction, hydro-aerodynamics and rotation. Changing any of these factors affects the entire process.
Associate professor of mechanical engineering at Tedd Truscott University, along with colleagues from the Naval Center for Underwater Research and Brown University, studied how an object deforms when it interacts with water.
Truscott and his team experimented with spherical objects made from various materials in a special reservoir, recording the results using high-speed cameras. They found that elastic balls behave in much the same way as thrown flat stones, that is, the more elastic an object is, the more lifting force occurs when it comes into contact with water. In addition, scientists have studied the essence of the physical processes occurring behind the object jumping on the water.
The results obtained will help to increase the efficiency of devices that move like a jumping bomb and to understand the principle of movement on water of some animals such as the basilisk lizard.