Abstract:
Several methods and apparatus for transferring heat, mass and momentum between a fluid and a surface are disclosed wherein the fluid is separated into a multiplicity of tiny jets that impinge upon a surface to be treated and flow across it for very short distances before reforming jets that leave the surface. While in contact with the surface, the fluid flow is laminar and the boundary layer that resists transfer of heat, mass and momentum is extremely thin. Hence, heat, mass and momentum transfer coefficients are large and predictable from first principles of physics. The pressure drop and fan power required to form these jets are generally less than that required to drive the flow parallel to the surface for long distances, where the boundary layer grows much thicker. Several examples and applications describe the versatility and increased effectiveness of the present method including fluid/surface heat transfer, fluid/fluid heat transfer, surface propulsion, surface levitation, surface skin drag and skin heating reduction, surface drying, surface cleaning, hair drying, ice melting, surface coating, surface chemical reactions, surface phase-change reactions, clean efficient coal combustion, air pollution control, and particle separation from fluids.