Abstracts Engineering

Gravity and surface tension-driven waves

by Albin Hedblom

In this thesis, gravity and surface tension-driven water waves are investigated by designing an experimental setup to track wave patterns using a 300 fps high speed camera. This is done to reproduce the theoretical diagram of the dispersion relation for surface waves in different teaching contexts. Surface waves are dispersive, i.e. the phase speed depends on the wavelength.Initially, the background theory for surface waves is presented and the differences between gravity and surface tension-driven waves are described. The conditions for deep and shallow water are also studied. Thereafter, a literature study is conducted to study similar experiments. Test experiments are then carried out where both direct and indirect methods of observing the waves are examined to determine which method generates the best images.The water waves in the experiment are generated by dropping a 1.6 cm marble and a 4 mm water droplet into a 35 cm diameter hexagonal tank filled with 1–10 cm deep water. The waves are recorded from above and illuminated by backlighting with a 10 W LED panel. The experimental results show that a 1.6 cm marble generates wavelengths in the 0.4–3.5 cm range. Moreover, for a 4 mm water droplet, wavelengths in the range of 0.4–2.5 cm are generated.