Leidenfrost gas ratchets driven by thermal creep

Alois Würger (1)

1 LOMA - Laboratoire Ondes et Matière d'Aquitaine

We show that thermal creep is at the origin of the recently discovered Leidenfrost ratchet, where liquid droplets float on a vapor layer along a heated saw-tooth surface and accelerate to velocities of up to 40 cm/s. As the active element, the asymmetric temperature profile at each ratchet summit rectifies the vapor flow in the boundary layer. This mechanism works at low Reynolds number and provides a novel tool for controlling gas flow at nanostructured surfaces.

Domaines: Matière Molle [cond-mat.soft]; Mécanique des fluides [physics.class-ph]; Mécanique des fluides [physics.class-ph]

Alois Würger. Leidenfrost gas ratchets driven by thermal creep. Physical Review Letters, 2011, 107, pp.164502 (4). ⟨10.1103/PhysRevLett.107.164502⟩. ⟨hal-00632232v1⟩