Abstract
Some peculiar characteristics of whistling sand from Kotobiki beach, Kakezu seashore in Kyoto Pref., which emits a squeak when walked on, has been studied from the view point of powder technology.
Examination with a optical microscope revealed that the particles were blocky with rounded and well polished edges. In comparison with usual silent sand, the whistling sand has very low compressibility when packed in a container with vibration, and then the mean coordination number, number of particles touched with neighboring of a particle, was about nine to ten.
Also cleanliness of particle surface and low moisture content were important factors for whistling phenomena.
Natural conditions of surface wearing was reproduced experimentally by ball mill grinding, and artificially abraded whistling sand, which shows features similar to those described, was successfully prepared.
