Numerical Investigation of Roll Wave in Guinness Beer

Abstract

To gain insight into the mechanism of texture formation of bubbles in a glass of Guinness beer, a numerical simulation of an unsteady flow in an inclined vessel is performed using Eulerian-Lagrangian approach with discrete element method. The texture formation can be reproduced by quasi-two-dimensional simulation. The velocity fluctuation is enhanced with increasing the initial particle volume fraction and with decreasing container inclination angle. Arranged using the Froude number Fr and the inverse resolution of concentration interface H, the numerical results of the velocity fluctuation magnitude strengthen the experimentally inferred argument that the texture formation is caused by a roll wave instability in the pure fluid layer, which postulates fluid-like behavior of the dispersed phase.