Vibration controlled foam yielding

Tutkimustuotos: LehtiartikkeliArticleScientificvertaisarvioitu

24 Lataukset (Pure)

Abstrakti

In rheological terms, foams are time independent yield stress fluids, displaying properties of both solid and liquid materials. Here we measure the propagation of a 2D dry foam in a radially symmetric Hele-Shaw cell forcing local yielding. The yield rate is manipulated by mechanical vibration with frequencies from 0 to 150 Hz. The flow speed is then extracted from the video stream and analyzed using digital image correlation software. The data are modeled analytically by a Guzman–Arrhenius type of energy landscape where the local yielding of foam correlates with the number of oscillations, i.e. attempts to cross the energy barrier. The model is confirmed in an auxiliary experiment where the vibrated foam stays in its flowing state at the same small driving pressures, where the flow of the unvibrated foam ceases. We conclude that the yield stress behaviour of foams under an external perturbation can be summarized using a simple energy landscape model. The vibration affects the films causing the stress to occasionally and locally exceed the yield threshold. This, thus, prevents the foam from jamming as in a static configuration even when the global driving is below the yield point of the foam.
AlkuperäiskieliEnglanti
Sivut9028-9034
Sivumäärä7
JulkaisuSoft Matter
Vuosikerta16
Numero39
DOI - pysyväislinkit
TilaJulkaistu - 21 lokak. 2020
OKM-julkaisutyyppiA1 Julkaistu artikkeli, soviteltu

Sormenjälki

Sukella tutkimusaiheisiin 'Vibration controlled foam yielding'. Ne muodostavat yhdessä ainutlaatuisen sormenjäljen.

Siteeraa tätä