Abstract: A method is disclosed of generating a predetermined field of cavitation around a remote target in an underwater environment. The method includes the steps of identifying a remote target location, generating at least two acoustic beams, each at a high power output, from an underwater acoustic source, and controlling the generated acoustic beams to intersect with each other at the remote target location and thereby create a destructive cavitation field at the intersection of the beams. The acoustic source and target can be located in unconfined underwater space and at a distance of at least 100 m apart.

Abstract: A boundary layer control device for a surface which reduces turbulence by oviding forces which counteract microturbulent events occurring at the surface. The microturbulent events occur periodically with a known topography and include liftup and ejection, bursting, low-speed streak and sweep topography. The device has an array of magnet and electrode cells which are arranged to correspond with the topography arrangement of the microturbulent events. The interaction of the magnetic and electric fields within the cells generate a Lorentz force which can be directed into or out of the surface depending on the relative directions of the magnetic and electric fields. Sensors on the surface determine which cells to activate and in what direction to apply the Lorentz force to precisely counteract the microturbulent events occurring at the surface. A force directed away from the surface is used to counteract a sweep event and a force directed towards the surface counteracts a liftup event.

Abstract: A method for controlling microturbulence in a medium flowing near a surface s disclosed. The method includes the steps of measuring the forces acting near or on the surface and using those measurements to determine the state probabilities for the microturbulent events occurring at the surface. The control method then activates selective cells in an array of cells to apply forces at the surface to counteract the microturbulent events and thus reduce turbulence. Each cell has a pair of electrodes and opposing magnetic poles such that when the control method activates a cell, the interaction of the electric field and the magnetic field at the cell creates a Lorentz force normal to the surface.

Abstract: A magnetohydrodynamic test facility using a superconducting electromagnet drive a hydrodynamic test loop is disclosed. The test facility has a pretreatment section for adjusting the salinity of seawater to be used in the flow loop a flow loop section having a test section, a magnetohydrodynamic pump, and a gas trap assembly to capture any gasses evolved from the seawater. A post-treatment section neutralizes evolved chlorine gasses.

Abstract: Electrodes and magnets are disposed in alternating relation on confronting urfaces of microgrooves that respectively produce electric and magnetic fields that are cooperative to provide a force that acts along a flow direction defined between a vessel and a relatively moving medium to controllably diminish turbulence generation in seawater.

Abstract: An electromagnetic thruster for marine vehicles using a jet of water driven by the interaction of a mutually perpendicular intensified magnetic field and an intensified electric field is disclosed. The intensified magnetic field is produced by superconducting coils cooled by a coolant such as liquid helium. An intensified electric field is produced by passing high amperage current across the seawater jet. These interacting fields produce a Lorentz force perpendicular to mutually perpendicular electric and magnetic field vectors which is used to drive the seawater jet. In some embodiments, the force may also be used to draw water into the jet from the boundary layer flow around the vehicle thereby reducing boundary layer turbulence and associated radiated noise.

Abstract: A torpedo launching system with a magnetohydrodynamic (MHD) pump for torp launches is disclosed. The system comprises a sea chamber, impulse tank and launch tube. The impulse tank has a magnetohydrodynamic pump which provides a Lorentz force to the seawater within the impulse tank thereby launching the torpedo. The MHD pump comprises supercooled superconducting electromagnets and seawater electrodes set up to provide perpendicular electric and magnetic fields.

Abstract: An active boundary layer control system for marine vehicles is disclosed. e boundary layer control system comprises a plurality of magnets and seawater electrodes placed in circumferential rows around the beam of the hull. The magnets and electrodes are positioned so that a Lorentz force generated by the interacting magnetic and electric fields will drive the boundary layer flow in an axial direction toward the aft end of the hull. The boundary control system reduces turbulence and may relaminarize boundary layer flow, thereby reducing radiated noise.