Capillary Wave and Initial Spreading Velocity at Impact of Drop onto a Surface

• Main Authors: P. F. Li, S. F. Wang, W. L. Dong
• Format: Article
• Language: English
• Published: Isfahan University of Technology 2019-01-01
• Series: Journal of Applied Fluid Mechanics
• Subjects: Drop impact; Capillary wave; initial spreading velocity; Impact velocity; Contact line.
• Online Access: http://jafmonline.net/JournalArchive/download?file_ID=49406&issue_ID=1001

The capillary wave and initial spreading velocity in the spreading phase of drop impacting on a glass surface are studied experimentally, while the drop photos are obtained by using a high-speed video camera, which can catch up to 9000 images per second with an exposure time of 4 µs. A wide range of impact velocities are studied by varying the fall height, showing different capillary waves. All attention is given to the capillary wave and initial spreading velocity of drop. A non-linear relation between the wavelength and the impact velocity is found experimentally. Combined with the minimum spreading radius theory, a linear relation between the initial spreading velocity and the impact velocity is acquired.