Interfacial instabilities in periodically driven Hele-Shaw flows.
We consider flow in a Hele-Shaw cell for which the upper plate moves up and down, making the fluid-fluid interface be driven periodically. To study such a flow we employ a mode-coupling approach, which allows the analytical assessment of important aspects about the stability and morphology of the evolving interface. At the linear level, it is shown that both the amplitude and the frequency of the drive have a significant role in determining the ultimate number of fingers formed. The influence of these factors on the mechanisms of finger competition and finger tip behavior at the onset of nonlinear effects is also studied.
Departamento de Física, LFTC, Universidade Federal de Pernambuco, Recife, Pernambuco 50670-901, PE, Brazil.
Eduardo O
EO
Dias
José A
JA
Miranda