A single parameter can predict surfactant impairment of superhydrophobic drag reduction.

ABSTRACT: Recent experimental and computational investigations have shown that trace amounts of surfactants, unavoidable in practice, can critically impair the drag reduction of superhydrophobic surfaces (SHSs), by inducing Marangoni stresses at the air-liquid interface. However, predictive models for realistic SHS geometries do not yet exist, which has limited the understanding and mitigation of these adverse surfactant effects. To address this issue, we derive a model for laminar, three-dimensional flow over SHS gratings as a function of geometry and soluble surfactant properties, which together encompass 10 dimensionless groups. We establish that the grating length g is the key geometric parameter and predict that the ratio between actual and surfactant-free slip increases with g

SUBMITTER: Temprano-Coleto F 

PROVIDER: S-EPMC9934013 | biostudies-literature | 2023 Jan

REPOSITORIES: biostudies-literature