The present invention relates to a fluid resistance reduction apparatus for a ship, and more particularly, to an apparatus for reducing fluid resistance of a ship, the apparatus capable of significantly reducing wave-making resistance as well as frictional resistance caused by seawater during navigation of a ship, thus improving the speed, allowing stable navigation, and saving fuel, wherein the fluid resistance reduction apparatus is disposed below the draft line of the hull and allows the ship to proceed while seawater is introduced through the bow due to rotation of a propeller disposed on the hull and is discharged through the back of the stern, thereby significantly reducing frictional resistance and wave-making resistance of seawater.

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.

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.

Wakeboat hull control systems and methods are provided to permit the accurate reproduction of a wake behind a wakeboat. The onboard wake control system receives data from a draft measuring system. Incorporation of the data from the draft measuring system permits accurate reproduction of a wake behind the wakeboat after a change in an onboard variable such as the number, weight or position of passengers, the weight or position of cargo and the position of trim tabs or amount/location of ballast.

Wakeboat hull control systems and methods are provided to permit the accurate reproduction of a wake behind a wakeboat. The onboard wake control system receives data from a draft measuring system. Incorporation of the data from the draft measuring system permits accurate reproduction of a wake behind the wakeboat after a change in an onboard variable such as the number, weight or position of passengers, the weight or position of cargo and the position of trim tabs or amount/location of ballast.

To provide an amphibious vehicle that can reduce wave drag at the time of hydroplaning and can improve propulsion performance of the vehicle body. An amphibious vehicle according to the present invention includes a vehicle body capable of moving on water and on land, a front flap with a rear end being fixed to a lower end of the vehicle body, a rear flap with a front end being fixed to a rear part of the vehicle body, and a pair of keels provided along a travel device provided on both sides of the vehicle body on a bottom surface of the vehicle body.

A method and apparatus for controlling an airflow. The method draws air through a group of inlets. The group of inlets is located in a group of locations on the vehicle such that the group of inlets actively controls the airflow relative to an aircraft when drawing the air. The method compresses the air drawn by the group of inlets in a group of air compressor units located in an aircraft structure to form pressurized air. Further, the method sends the pressurized air through a group of exit ports in the aircraft structure. The pressurized air flowing out of the group of exit ports actively controls the airflow for an aircraft, enabling an improved performance of the aircraft.

A method and apparatus for controlling an airflow. The method draws air through a group of inlets. The group of inlets is located in a group of locations on the vehicle such that the group of inlets actively controls the airflow relative to an aircraft when drawing the air. The method compresses the air drawn by the group of inlets in a group of air compressor units located in an aircraft structure to form pressurized air. Further, the method sends the pressurized air through a group of exit ports in the aircraft structure. The pressurized air flowing out of the group of exit ports actively controls the airflow for an aircraft, enabling an improved performance of the aircraft.

A wake control system aft of the driveshaft, propeller, and rudder of a vessel includes a fin base and at least one fin slidingly engaged with the fin base. The fin(s) are vertically oriented and extend down into the water surface. The fins are transversely adjustable along the fin base to redirect a wake generated by the boat. In other embodiments, the control system comprises a starboard fin tab adjacent to a port fin tab, each of the independent fin tabs hingeably attached to the aft section of the hull, at the transom. Each fin tab includes at least one extending fin. Fin tabs are selectively deployable and retractable into and out of the water surface to redirect a wake generated by the vessel from one side to the other. A novel underwater exhaust system redirects exhaust depending on speed of the vessel and complements the wake control system.

A wake control system aft of the driveshaft, propeller, and rudder of a vessel includes a fin base and at least one fin slidingly engaged with the fin base. The fin(s) are vertically oriented and extend down into the water surface. The fins are transversely adjustable along the fin base to redirect a wake generated by the boat. In other embodiments, the control system comprises a starboard fin tab adjacent to a port fin tab, each of the independent fin tabs hingeably attached to the aft section of the hull, at the transom. Each fin tab includes at least one extending fin. Fin tabs are selectively deployable and retractable into and out of the water surface to redirect a wake generated by the vessel from one side to the other. A novel underwater exhaust system redirects exhaust depending on speed of the vessel and complements the wake control system.