Abstract: An apparatus and method for reducing surface friction drag on the hull of a surface vessel by entraining air into water flowing in the boundary layer flow along the hull. The apparatus creates a reduced pressure region by diverting a first portion of the flow away from the surface of the hull. An air pocket is formed in the reduced pressure region and a second portion of the flow is directed through the air pocket by nozzles, which acts as a plunging jet and entrains air into the boundary layer.

Abstract: An apparatus and method for reducing surface friction drag on the hull of a surface vessel by entraining air into water flowing in the boundary layer flow along the hull. A hemispherical protrusion creates flow separation by diverting a portion of the water flow away from the surface of the hull, which results in a reduced pressure region downstream from the protrusion. A vent located on the protrusion allow air to flow into the reduced pressure region. The air in the reduced pressure region is entrained into the water due to turbulent mixing from vortices shed on to the rear of the protrusion.

Abstract: An apparatus and method for reducing surface friction drag on the hull of a surface vessel by entraining air into water flowing in the boundary layer flow along the hull. The apparatus creates a reduced pressure region by diverting a first portion of the flow away from the surface of the hull. An air pocket is formed in the reduced pressure region and a second portion of the flow is directed through the air pocket by nozzles, which acts as a plunging jet and entrains air into the boundary layer.

Abstract: A support structure for a shoe includes a bladder arrangement having at least one (and preferably two) fluid-filled chamber arranged in a heel region of the sole of the shoe. The fluid-filled chamber has outer walls with a pressurized fluid disposed therein. The fluid-filled chamber is configured to be compressively deformed when an external pressure is applied thereto, such as the pressure exerted by a wearer's foot. The support structure also includes at least one pillar disposed in the fluid-filled chamber. The pillars are configured to decrease the amount by which the fluid-filled chamber is compressively deformed when the external pressure is applied thereto, while still permitting the fluid-filled chambers to be deformed sufficiently to provide adequate protection against the force of impact during use.

Abstract: A support structure for a shoe includes a bladder arrangement having at least one (and preferably two) fluid-filled chamber arranged in a heel region of the sole of the shoe. The fluid-filled chamber has outer walls with a pressurized fluid disposed therein. The fluid-filled chamber is configured to be compressively deformed when an external pressure is applied thereto, such as the pressure exerted by a wearer's foot. The support structure also includes at least one pillar disposed in the fluid-filled chamber. The pillars are configured to decrease the amount by which the fluid-filled chamber is compressively deformed when the external pressure is applied thereto, while still permitting the fluid-filled chambers to be deformed sufficiently to provide-adequate protection against the force of impact during use.

Abstract: A cushioning device that imparts both stability and cushioning to the midsole of an athletic shoe. The cushioning device includes a bladder that has a plurality of separate fluid chambers positioned around a perimeter. The chambers define an open central portion of the bladder arrangement. Each of the chambers has an inner side, an outer side and a height that increases from a minimum adjacent the inner side to a maximum toward the outer side thereof.

Abstract: A support structure for a shoe includes a bladder arrangement having at least one (and preferably two) fluid-filled chamber arranged in a heel region of the sole of the shoe. The fluid-filled chamber has outer walls with a pressurized fluid disposed therein. The fluid-filled chamber is configured to be compressively deformed when an external pressure is applied thereto, such as the pressure exerted by a wearer's foot. The support structure also includes at least one pillar disposed in the fluid-filled chamber. The pillars are configured to decrease the amount by which the fluid-filled chamber is compressively deformed when the external pressure is applied thereto, while still permitting the fluid-filled chambers to be deformed sufficiently to provide-adequate protection against the force of impact during use.

Abstract: A cushioning device that imparts both stability and cushioning to the midsole of an athletic shoe. The cushioning device includes a bladder that has a plurality of separate fluid chambers positioned around a perimeter. The chambers define an open central portion of the bladder arrangement. Each of the chambers has an inner side, an outer side and a height that increases from a minimum adjacent the inner side to a maximum toward the outer side thereof.