Fluid dynamics is the study of the motion of liquids, gases and plasmas. Flow is dependent on the intrinsic properties of the matter itself, such as compressibility, viscosity and density.

Six basic taste stimuli were used: sucrose, NaCl, citric acid, QHCl, MSG (all Kanto Chemical), and Intralipos (a parenteral-stable soybean oil emulsion; Otsuka Pharmaceutical Factory, Tokyo, Japan).