Off-centre impact on a horizontal fibre

Abstract

Fibre filters that consist of a network of randomly oriented thin fibres are commonly used to recover the liquid phase from an aerosol. During the filtration process, drops of the aerosol impact the solid fibres of the filter. If the impact velocity is smaller than a threshold velocity V_c, the drop is entirely captured by the fibre whereas if the velocity is larger than V_c, only a small portion of fluid remains trapped on the solid fibre. While this threshold velocity has been determined when the impact is centred – i.e. when the trajectory of the drop and the axis of the fibre do intersect – fewer studies are related to off-centre impact. Here, we focus on the influence of the relative position of the drop and the fibre on the impact. For velocity larger than V_c, we vary the eccentricity and measure the ability of the fibre to retain the liquid phase. Quite surprisingly, we show that off-centre impact situation enhances the ability of the fibre to capture a portion of the drop.