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Cavitation is usually divided into two classes of behavior. Inertial (or transient) cavitation is the process in which a void or bubble in a liquid rapidly collapses, producing a shock wave. It occurs in nature in the strikes of mantis shrimp and pistol shrimp, as well as in the vascular tissues of plants.
A simple hydraulic pumping circuit. Point O is the free suction surface, and point i is the inlet of the impeller. In a pump, cavitation will first occur at the inlet of the impeller. [1] Denoting the inlet by i, the NPSH A at this point is defined as:
The cavitation number (Ca) can be used to predict hydrodynamic cavitation.It has a similar structure as the Euler number, but a different meaning and use: . The cavitation number expresses the relationship between the difference of a local absolute pressure from the vapor pressure and the kinetic energy per volume, and is used to characterize the potential of the flow to cavitate.
Supercavitation is the use of a cavitation bubble to reduce skin friction drag on a submerged object and enable high speeds. Applications include torpedoes and propellers , but in theory, the technique could be extended to an entire underwater vessel.
There were several hypotheses to explain the cracking of joints. Synovial fluid cavitation has some evidence to support it. [9] When a spinal manipulation is performed, the applied force separates the articular surfaces of a fully encapsulated synovial joint, which in turn creates a reduction in pressure within the joint cavity.
The Rayleigh–Plesset equation is often applied to the study of cavitation bubbles, shown here forming behind a propeller.. In fluid mechanics, the Rayleigh–Plesset equation or Besant–Rayleigh–Plesset equation is a nonlinear ordinary differential equation which governs the dynamics of a spherical bubble in an infinite body of incompressible fluid.
Its blades are wedge-shaped to force cavitation at the leading edge and to avoid water skin friction along the whole forward face. As the cavity collapses well behind the blade, the supercavitating propeller avoids the spalling damage due to cavitation that is a problem with conventional propellers.
In addition to chemical and physical weathering of hydraulic action, freeze-thaw cycles, and more, there is a suite of processes which have long been considered to contribute significantly to bedrock channel erosion include plucking, abrasion (due to both bedload and suspended load), solution, and cavitation.