Abstract: A test rig for measuring wear on flexible membrane material used as seal gers on air cushion vehicles includes a pump and nozzle for producing a shallow, high speed water flow and hydraulic actuators for moving the seal fingers into the flow. The fingers are moved into and out of the flow to simulate the effect of the ship crossing waves at high speed. A fan and air plenum inflate the seal fingers in a manner similar to normal operation.

Abstract: The purpose of this invention is to improve the life of transversely stiffened membrane (TSM) seals. To this end the inventors have introduced a segmented glass reinforced plastic (GRP) plank into the lower stiffened lobe portion, which is positioned beneath the bag segments of the TSM seal. The segmented (GRP) planks consist of planks separated by rubber spacers and sandwiched between two sheets of rubber coated nylon fabric.

Abstract: A seal structure for an air cushion vessel includes an inflatable bag secured to the hull and a transversely stiffened lobe portion maintained therebeneath. The stiffened lobe portion consists of a membrane with an array of spaced, transverse stiffener members connected thereto. The colinear stiffener members are interconnected in end-to-end relationship. According to one embodiment, the end portions of the stiffener members are connected to support stays which are connected either to the bag structure or to the forward portion of the hull. The support stays may comprise cable elements or membranes which form continuations of the stiffened lobe membrane. Additional support for the stiffened lobe portion is provided in the form of a plurality of rear support elements which set the orientation and configuration of the stiffened lobe portion and limit the downward deflection of the stiffened lobe portion.

Abstract: A seal structure for an air cushion vessel includes an inflatable bag secd to the hull and a transversely stiffened lobe portion maintained therebeneath. The stiffened lobe portion consists of a membrane with an array of spaced, transverse stiffener members connected thereto. The colinear stiffener members are interconnected in end-to-end relationship.Generally, the end portions of the stiffener members are connected to support stays which are connected either to the bag structure or to the forward portion of the hull. The support stays may comprise cable elements or membranes which form continuations of the stiffened lobe membrane.Additional support for the stiffened lobe portion is provided in the form of a plurality of rear support elements which set the orientation and configuration of the stiffened lobe portion and limit the downward deflection of the stiffened lobe portion.

Abstract: A seal structure for an air cushion vessel includes an inflatable bag secd to the hull and a plurality of juxtaposed, interconnected planer members maintained in operative position beneath the bag by a plurality of support straps. Each planer member includes a transversely reinforced shell portion and a flexible, resilient membrane secured to the longitudinal edge portions of the shell portion to form a flexible planing surface for the seal structure. The planer members may have tapered aft end portions and curved planing surfaces to provide a gradual change of the interface between the planer members and the water.

Abstract: An arrangement for controlling the apparent curvature of diffuser vanes of turbine fan to reduce stalling of the vanes and increase efficiency of the fan output over a wider range of flow demand. Sensors responsive to pressure on opposite sides of the vanes selectively control the discharge of pressurized fluid from the diffuser vanes to effect their apparent curvature changes. The arrangement has particular use in a ride control system for surface effect ships.

Abstract: A variable flow diffuser for use in air cushion vehicles to convert the ktic energy of the moving air from the main fan into potential energy of air pressure. The conversion is accomplished by passing the air flow from the fan through a flow splitter and diverting it radially outward in all directions along a plane perpendicular to the initial direction of the air flow. The volume of air passing through the diffuser is controlled by placing control vanes around the flow splitter or by moving the flow splitter and a back plate in and out of the air channel.