Fig. 2.

(a) The theoretical calculations of capillary waves and gravity waves in deep water and shallow water. The critical wavelength ${\lambda }_c$ is found to be 17.25 mm and the associated minimum phase velocity $C_{p(min)}$ is 0.231 m/s. The blue line and black line are waves in deep water and in shallow water, respectively. (b) The critical wavelengths ${\lambda }_c$ in three fluids, water, plasma and whole blood, were calculated.