Fig. 2: Modeling the perceived thickness of liquid bouillons.
From: Predicting thickness perception of liquid food products from their non-Newtonian rheology
A Assessing the thickness of a liquid involves two organs (top): the palate and the tongue. In our approach, we consider that the liquid bouillon covers a circular area of radius R on the tongue (bottom). B The maximum radius of coverage R is determined by licking a piece of paper. C To determine the wetting properties of the liquid bouillons, small droplets are deposited onto paper and the resulting contact angle θ is measured. D Sketch of the geometry used to model fluid deformation in the mouth (i). Because of the softness and deformability of the tongue compared to the palate (ii), the two organs can be approximated as two parallel plates separated by a distance h and pressed together with a constant force FN (iii). The bottom plate (tongue) moves at a speed V relative to the top (palate) to deform the trapped liquid, squeezing out the fluid from the (bucal) cavity. ux stands for the velocity component along x, which here varies with height z.
