71th Annual Meeting of the APS Division of Fluid Dynamics (November 18, 2018 — November 20, 2018)

V0072: Impact of a linear array of hydrophilic and superhydrophobic spheres on water pool

Authors

• Guang Yang, Institute of Aerospace Thermodynamics, University of Stuttgart
• Visakh Vaikuntanathan, Institute of Aerospace Thermodynamics, University of Stuttgart
• Alexandros Terzis, Institute of Aerospace Thermodynamics, University of Stuttgart
• Bernhard Weigand, Institute of Aerospace Thermodynamics, University of Stuttgart
• Rainer Helmig, Institute for Modelling Hydraulic and Environmental Systems, University of Stuttgart

DOI: https://doi.org/10.1103/APS.DFD.2018.GFM.V0072

It is quite well-known that by altering the surface wetting characteristics of a solid sphere impacting on a deep water pool, the formation and evolution of underwater cavity in its wake can be controlled. The video shows the results from a preliminary study on impact of a linear array of hydrophilic (H) and superhydrophobic (SH) spheres on a deep water pool. The current study is aimed at introducing an additional parameter, namely the position of the first SH sphere in the array, in governing the evolution of underwater cavity. We show that as the first SH sphere is placed farther away from the leading edge of the array, the cavity formation becomes less pronounced. In addition, we show that the wake cavity behind the trailing edge of the linear array can be controlled by tuning the wetting characteristics of the leading and trailing surfaces in the array.