Figure 7
From: Bubble cascade in Guinness beer is caused by gravity current instability
Falling fluid film model for texture-formation. (a) Particle separation in the wall vicinity. The fluid can be divided into a clear-fluid region with a density of ρ0 (above the inclined wall) and a suspension region with a density of ρs = (1 − α) ρ0 + α ρ1, where α and ρ1 are the volume concentrations of the dispersed phase and the density, respectively. (b) Time-averaged velocity along the wall \({\bar{u}}_{x}\) (upper), and root-mean-square value of the fluctuation component \({u}_{x}^{^{\prime} }\) (lower) versus wall-normal distance y. (c) Scaled velocity fluctuation for various experimental conditions as a function of Reynolds number (left) and Froude number (right). The experimental data are plotted 10 seconds after pouring the fluid and are averaged over 10 seconds at several instants, where error bars indicate resolutions in the measurements.
