An apparatus including a controllable fluid-contacting surface is provided. In another aspect, the present apparatus includes a flexible membrane and multiple actuators each having an output shaft or activation member coupled to a water-contacting membrane, with the shafts extending in a direction offset from the nominal outer surface of the membrane. A further aspect of the present apparatus includes an underwater vessel including a propulsion source, a flexible membrane having a water-contacting outer surface and an electronic controller including programmable software for actuating the actuators.

A ground effect craft having a ground effect wing, a plurality of sponsons, and a control system is disclosed. The ground effect wing may include a fore ground effect wing and an aft ground effect wing. The ground effect wing may generate a stabilizing moment on at least one sponson to stabilize the ground effect craft. The plurality of sponsons may be dynamically coupled to the body. The plurality of sponsons may be dynamically coupled to each other. The dynamic coupling may permit the sponsons to move relatively independent of the body and each other, thereby stabilizing the ground effect craft. The ground effect craft may include a stabilizing wing.

A personal watercraft hull has a bow, a keel, starboard and port upper edges, a starboard portion extending between the keel and the starboard upper edge, a port portion extending between the keel and the starboard upper edge, and a transom. The starboard portion has a starboard row of grooves. The port portion has a port row of grooves. The rows of grooves extend in a longitudinal direction and are laterally offset from the longitudinal centerline and from their corresponding upper edge. The grooves of the rows of grooves define recesses in an outer surface of the hull. A personal watercraft having the personal watercraft hull is also disclosed.

A profiled element used is disclosed for generating a force, the profiled element comprising a material having an active surface; a plurality of cavities located on the active surface of the material, the plurality of cavities comprising pin holes, each pin hole having an opening of a micrometric size on the active surface and a depth of a micrometric size greater than its diameter; wherein each pin hole is hermetically sealed on the opposite side of the cavity; and further wherein an airflow circulation against the active surface of the material causes a pressure change on the active surface and inside each of the plurality of cavities thereby generating a force.

A novel mechanism for reducing boundary layer friction and inhibiting the effects of uncontrolled fluid turbulence and turbulent layer separation, thus reducing the body drag, kinetic energy losses and lowering engine and pump fuel consumption is proposed. It steps on the type of turbulence observed in the so-called in fluid dynamics “drag crisis”. Plurality of device shapes and plurality of devices producing the wanted pure form of even plurality of counter-rotating vortices extending into the flow, i.e. tubes, are presented and discussed in detail, contrasting with the prior art. Configurations of multiple devices for the purposes of drag and fuel reduction, including their simulations and experimental results are put forward. Additional embodiments of the resulting tubes disclose use on aircraft or vessel control surfaces as stall inhibitors, use in wind turbines as dynamic range extenders, as well as use in turbines in efficient cooling mechanisms.

A novel mechanism for reducing boundary layer friction and inhibiting the effects of uncontrolled fluid turbulence and turbulent layer separation, thus reducing the body drag, kinetic energy losses and lowering engine and pump fuel consumption is proposed. It steps on the type of turbulence observed in the so-called in fluid dynamics “drag crisis”. Plurality of device shapes and plurality of devices producing the wanted pure form of even plurality of counter-rotating vortices extending into the flow, i.e. tubes, are presented and discussed in detail, contrasting with the prior art. Configurations of multiple devices for the purposes of drag and fuel reduction, including their simulations and experimental results are put forward. Additional embodiments of the resulting tubes disclose use on aircraft or vessel control surfaces as stall inhibitors, use in wind turbines as dynamic range extenders, as well as use in turbines in efficient cooling mechanisms.

A vehicle includes a surface for contacting a fluid medium through which the vehicle is propelled. The vehicle also includes an array of transducers and a controller. The transducers in the array are arranged across the vehicle's surface for generating pressure waves in the fluid medium. Each transducer in the array is arranged to vibrate for generating a respective pressure wave, which propagates away from the surface in the fluid medium. The controller vibrates the transducers in the array so that the pressure waves control the drag of the vehicle from the fluid medium.

A ground effect craft having a ground effect wing, a plurality of sponsons, and a control system is disclosed. The ground effect wing may include a fore ground effect wing and an aft ground effect wing. The ground effect wing may generate a stabilizing moment on at least one sponson to stabilize the ground effect craft. The plurality of sponsons may be dynamically coupled to the body. The plurality of sponsons may be dynamically coupled to each other. The dynamic coupling may permit the sponsons to move relatively independent of the body and each other, thereby stabilizing the ground effect craft. The ground effect craft may include a stabilizing wing.

A ground effect craft having a ground effect wing, a plurality of sponsons, and a control system is disclosed. The ground effect wing may include a fore ground effect wing and an aft ground effect wing. The ground effect wing may generate a stabilizing moment on at least one sponson to stabilize the around effect craft. The plurality of sponsons may be dynamically coupled to the body. The plurality of sponsons may be dynamically coupled to each other. The dynamic coupling may permit the sponsons to move relatively independent of the body and each other, thereby stabilizing the ground effect craft. The ground effect craft may include a stabilizing wing.

The novel bladder systems and tie down systems set forth herein provide systems and apparatuses that mitigate or prevent damage, such as tipping over/capsizing, of a watercraft stored on shore or an aircraft secured to a ground surface during adverse wind, rising water, or storm events. Further, novel apparatuses and methods for storing a watercraft using the bladders as cushioning or holding devices when installed within a cavity, whether the cavity is created by digging a hole or building an enclosing berm, provides additional stability and security for the watercraft during adverse wind, rising water, or storm events.