Abstract: A torque sensing device includes a rotating component configured to rotate about an axis of rotation and a first sensor positioned adjacent to the rotating component to sense instantaneous angular position of the rotating component at a first location. A second sensor is positioned adjacent to the rotating component radially inboard of the first sensor to sense instantaneous angular position of the rotating component at a second location. A controller is operably coupled to the first sensor and the second sensor. The controller determines a relative phase shift between a first signal generated by the first sensor and a second signal generated by the second sensor to calculate an output proportional to a torque applied to the rotating component.

Abstract: A torque sensing device includes a rotating component configured to rotate about an axis of rotation and a first sensor positioned adjacent to the rotating component to sense instantaneous angular position of the rotating component at a first location. A second sensor is positioned adjacent to the rotating component radially inboard of the first sensor to sense instantaneous angular position of the rotating component at a second location. A controller is operably coupled to the first sensor and the second sensor. The controller determines a relative phase shift between a first signal generated by the first sensor and a second signal generated by the second sensor to calculate an output proportional to a torque applied to the rotating component.

Abstract: A composition for reducing vibrations, including both damping structureborne vibrations and reducing radiated airborne noise. The composition is either a mixture of at least two different granular materials, or is a granular material having a bulk sound speed of less than 90 m/s. The damping properties of a mixture can be calculated from the bulk densities and stiffnesses of its individual components.

Abstract: The invention relates to the use of low-density granular fill with a specific gravity less than 1.5, placed in hollow cavities built into turbomachinery blades, vanes, and shafts. The granular fill provides effective damping at lower frequencies than conventional passive damping treatment due to its low bulk compressional sound speed. Selected materials used for the granular fill treatment are chosen for specific turbomachinery needs, including temperature of operation. Rotation speed is also a factor because it induces on the granular material an apparent hydrostatic pressure associated with the centripetal acceleration, and sound speed in granular materials is a function of pressure raised to the power 1/n. Preferred designs for placement of low-density granular material in appendages and shafts are found using an iterative design tool based on the Direct Global Stiffness Matrix method.

Abstract: The damped structural member includes a structural member and granular material in intimate contact with the member. In one embodiment the granular material is lightweight and has a bulk specific gravity of less than 1.5. When low weight is important, the granular material has a bulk specific gravity of less than or equal to one. The particles of the granular material are also in intimate contact with one another. The granular material may be substantially non-viscoelastic. Preferred granular material is low density polyethylene and glass microspheres. The granular material fills hollow structural members or is placed into intimate contact with open structural members. The lightweight fill effectively damps vibrational modes without excessively increasing the weight of the structural member.

Abstract: The following relates to the use of low-density granular fill with a specific gravity less than 1.5, placed in hollow cavities built into turbomachinery blades, vanes, and shafts. The granular fill provides effective damping at lower frequencies than conventional passive damping treatment due to its low bulk compressional sound speed. Selected materials used for the granular fill treatment are chosen for specific turbomachinery needs, including temperature of operation. Rotation speed is also a factor because it induces on the granular material an apparent hydrostatic pressure associated with the centripetal acceleration, and sound speed in granular materials is a function of pressure raised to the power 1/n. Preferred designs for placement of low-density granular material in appendages and shafts are found using an iterative design tool based on the Direct Global Stiffness Matrix method.

Abstract: The damped structural member includes a structural member and granular material in intimate contact with the member. In one embodiment the granular material is lightweight and has a bulk specific gravity of less than 1.5. When low weight is important, the granular material has a bulk specific gravity of less than or equal to one. The particles of the granular material are also in intimate contact with one another. The granular material may be substantially non-viscoelastic. Preferred granular material is low density polyethylene and glass microspheres. The granular material fills hollow structural members or is placed into intimate contact with open structural members. The lightweight fill effectively damps vibrational modes without excessively increasing the weight of the structural member.

Abstract: Oxygen and propane are supplied to the combustion chamber of a marine seismic gas exploder from a pair of pressure regulated gas charging cylinders. Ignition of the resultant explosive gas mixture drives a piston connected with means for creating an acoustic disturbance in the water. The outputs from the charging cylinders are fed simultaneously to a mixing manifold connected to a large orifice communicating with the combustion chamber.The ratio of gases in the resultant mixture is automatically determined by the relative volumes and pressures of the charging cylinders, which may be precisely regulated by adjustment of pistons movable within such cylinders and by gas pressure regulation. To safeguard against too rapid voiding of a small volume charging cylinder, voiding of the larger volume cylinder may be initiated first with the aid of a choke downstream of the manifold. This will create an artificial back pressure in the distribution system.