Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : September 03, 2023 - September 06, 2023
In our laboratory, the self-running mechanism of Leidenfrost-state droplets on a substrate with a sawteeth have been investigated, for the purpose of developing a new power source. In this presentation, the modification of the experimental system will be introduced. And consideration of the mechanism by which the thermal energy supplied to the droplets from the substrate drives the droplet, as described below, will be reported. First, it is assumed that the velocity of the droplet running on the sawteeth substrate becomes constant because the shear stress exerted by the vapor on the bottom surface of the droplets is balanced with the air resistance acting on the front surface of the droplet in the traveling direction, and the velocity (ut) of the vapor that blows off the surface of the droplet in the direction of travel of the droplet was obtained. Comparing with the vapor velocity (us) ejected from the stationary Leidenfrost state droplet surface on a flat substrate, it was found that ut is only about 1% of us at most. In other words, it was found that most of the steam spewed out in a direction that had nothing to do with the direction in which the droplet traveled.
