High Speed Visualization and Analysis of Maximum Spreading of Water Droplet during Impact on Hot Horizontal Surface

摘要

This paper discusses about droplet spreading phenomena during impact with hot surface in the film boiling region. In this experiment, aluminum material was selected as a test surface. Degassed and distilled water was used as the test liquid. The water droplet diameter, D_o was 4.0 mm and the droplet temperature was fixed at 16.0℃. The droplet falling height was 65.0 mm corresponding to droplet impact velocity, v of 1.129 m/s. This unique droplet impact phenomenon was recorded at 10,000 frames per second (fps) by using a high speed camera. Results show that variation in surface temperature does not affect the spreading dynamics of water droplet in the film boiling region. The measured residence time also agrees closely with the theoretical calculation.