Abstract: A non-destructive evaluation technique particularly suited for in situ testing utilizes significant changes in internal friction damping (IFD) as an indicating factor. A baseline for the specific damping capacity of an object is determined and a tolerance range is established from the baseline. Measurements of the specific damping capacity are periodically made and checked to see if they are within the tolerance range. Unexpected changes in specific damping capacity indicate the presence of an incipient flaw in the object. The evaluation technique can also be used to locate flaws, monitor crack growth and predict useful life. Apparatus for measuring specific damping capacity is also disclosed.

Abstract: A process and apparatus for high speed material removal with relatively low specific energy input requirements are disclosed. The apparatus includes a system for supplying pressurized fluid at a predetermined flow rate and pressure to an orifice of predetermined diameter. The system establishes a fluid flow to an environment in which there exists cavitation downstream of the orifice. The orifice size, position relative to the surface being treated, the fluid velocity and fluid pressure are determined with reference to the erosion strength of the particular parent material to be removed so as to effect highly efficient rapid cutting, drilling, cleaning and the like. The process includes the generation of a cavitation-free fluid flow through the orifice such that a submerged cavitating flow field is established downstream of that orifice. The velocity of fluid flowing through the orifice is selected to provide a cavitation intensity which exceeds the threshold erosion intensity of the material to be removed.

Abstract: A method and apparatus are disclosed for the homogenization of a multicomponent stream including a liquid and a substantially insoluble component, which may be either a liquid or a finely divided solid. The homogenization process is effected by passing the multicomponent, fluid stream through a turbulent shear layer having a substantial velocity gradient there-across and designed such that turbulent vortical eddies generate a cavitating flow regime. The cavitating flow regime allows the generation of vapor bubbles which move downstream into a region of pressure and violently collapse. The violent bubble collapse creates intense pressure pulses which cause the intimate intermixing of the liquid and the substantially insoluble component such that the effluent, a resulting emulsion, has an exceptionally long separation half-life with a very high emulsification coefficient.