Several Interesting Characters of Capillary-Gravity Wave

At the liquid-air interface, if there exist any moving disturbances, like a water-walking insect or just a simple pressure source, it will generate capillary-gravity waves [1-4]. The restoring force in this picture is a combination of the gravity and surface tension. And since the disturbance expends a power to generate these waves, it will experience a drag, known as the wave resistance [5]. Such resistance is equally important in both the large scale hydro-phenomenon, such as ship wave resistance [6], and the small scale, such as the insect eco-locomotion [7-9]. And in these two cases, the effects of the gravity and surface tension will play different roles, since they dominate the phenomena in different regions, owing to its complex dispersion relationship [10, 11].