Bouncing of Leidenfrost steel balls on water surface

A steel ball with a density higher than that of water can bounce on a water surface when heated to a temperature well above the Leidenfrost point. In this letter, an experiment is conducted where heated steel balls are released onto a water surface. The heated steel ball descends into the liquid, thus causing the liquid to evaporate and form a vapor cushion with an upward force that lifts the steel ball. Subsequently, the steel ball bounces off the water surface, like a solid ball bouncing off an elastic surface without sinking into the water. This phenomenon is known as the inverse Leidenfrost effect. In this letter, we evaluate the various motion behaviors of spheres at different Reynolds numbers and temperatures. Additionally, we analyze the bouncing behavior of solid spheres on a free liquid surface and examine the various force components.