Acoustic Radiation Pressure

	Acoustic Radiation Pressure Acoustic radiation pressure is the apparent pressure difference between the average pressure at a surface moving with the displacement of the wave propagation (the Lagrangian pressure) and the pressure that would have existed in the fluid of the same mean density when at rest. Numerous authors make a distinction between the phenomena of Rayleigh radiation pressure and Langevin radiation pressure. See also * Radiation pressure * Acoustic levitation * Acoustic radiation force Acoustic radiation force (ARF) is a physical phenomenon resulting from the interaction of an acoustic wave with an obstacle placed along its path. Generally, the force exerted on the obstacle is evaluated by integrating the acoustic radiation pressu ... References * * * * External links Tokyo University Researchers Using Ultrasound Technology to Enable Touchable Holograms Acoustics {{acoustics-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Wave Propagation Wave propagation is any of the ways in which waves travel. Single wave propagation can be calculated by 2nd order wave equation ( standing wavefield) or 1st order one-way wave equation. With respect to the direction of the oscillation relative to the propagation direction, we can distinguish between longitudinal wave and transverse waves. For electromagnetic waves, propagation may occur in a vacuum as well as in the material medium. Other wave types cannot propagate through a vacuum and need a transmission medium to exist. Reflection of plane waves in a half-space The propagation and reflection of plane waves—e.g. Pressure waves (P-wave) or Shear waves (SH or SV-waves) are phenomena that were first characterized within the field of classical seismology, and are now considered fundamental concepts in modern seismic tomography. The analytical solution to this problem exists and is well known. The frequency domain solution can be obtained by first finding the Helmholtz deco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Lagrangian Pressure Lagrangian may refer to: Mathematics * Lagrangian function, used to solve constrained minimization problems in optimization theory; see Lagrange multiplier Lagrangian relaxation, the method of approximating a difficult constrained problem with an easier problem having an enlarged feasible set Lagrangian dual problem, the problem of maximizing the value of the Lagrangian function, in terms of the Lagrange-multiplier variable; See Dual problem * Lagrangian, a functional whose extrema are to be determined in the calculus of variations * Lagrangian submanifold, a class of submanifolds in symplectic geometry * Lagrangian system, a pair consisting of a smooth fiber bundle and a Lagrangian density Physics * Lagrangian mechanics, a reformulation of classical mechanics * Lagrangian (field theory), a formalism in classical field theory * Lagrangian point, a position in an orbital configuration of two large bodies * Lagrangian coordinates, a way of describing the motions of particles ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Rayleigh Radiation Pressure Rayleigh may refer to: Science * Rayleigh scattering * Rayleigh–Jeans law * Rayleigh waves Rayleigh (unit), a unit of photon flux named after the 4th Baron Rayleigh Rayl, rayl or Rayleigh, two units of specific acoustic impedance and characteristic acoustic impedance, named after the 3rd Baron Rayleigh Rayleigh criterion in angular resolution Rayleigh distribution Rayleigh fading Rayleigh law on low-field magnetization Rayleigh length Rayleigh number, a dimensionless number for a fluid associated with buoyancy driven flow Rayleigh quotient Rayleigh–Ritz method * Plateau–Rayleigh instability explains why a falling stream of fluid breaks up into smaller packets * Rayleigh–Taylor instability an instability of an interface between two fluids Title of nobility * Baron Rayleigh Charlotte Mary Gertrude Strutt, 1st Baroness Rayleigh John William Strutt, 3rd Baron Rayleigh, physicist, winner of a Nobel Prize in 1904 Robert John Strutt, 4th Baron Rayleigh, physi ... [...More Info...] [...Related Items...] OR:** [Wikipedia] [Google] [Baidu]
	Langevin Radiation Pressure Langevin may refer to: * Langevin (surname) * 5290 Langevin, an asteroid * Langevin (crater) on the Moon See also * Institut Laue–Langevin, scientific facility in Grenoble, France * Office of the Prime Minister and Privy Council, a government office building in Ottawa, Canada formerly called Langevin Block * Physics and mathematics (named for Paul Langevin): Langevin's function (and its relation to Brillouin's) Langevin dynamics Langevin equation In physics, a Langevin equation (named after Paul Langevin) is a stochastic differential equation describing how a system evolves when subjected to a combination of deterministic and fluctuating ("random") forces. The dependent variables in a Lange ... {{Disambig ... [...More Info...] [...Related Items...] OR:** [Wikipedia] [Google] [Baidu]
picture info	Radiation Pressure Radiation pressure is the mechanical pressure exerted upon any surface due to the exchange of momentum between the object and the electromagnetic field. This includes the momentum of light or electromagnetic radiation of any wavelength that is absorbed, reflected, or otherwise emitted (e.g. black-body radiation) by matter on any scale (from macroscopic objects to dust particles to gas molecules). The associated force is called the radiation pressure force, or sometimes just the force of light. The forces generated by radiation pressure are generally too small to be noticed under everyday circumstances; however, they are important in some physical processes and technologies. This particularly includes objects in outer space, where it is usually the main force acting on objects besides gravity, and where the net effect of a tiny force may have a large cumulative effect over long periods of time. For example, had the effects of the Sun's radiation pressure on the spacecraft of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Acoustic Levitation Acoustic levitation is a method for suspending matter in air against gravity using acoustic radiation pressure from high intensity sound waves. It works on the same principles as acoustic tweezers by harnessing acoustic radiation forces. However acoustic tweezers are generally small scale devices which operate in a fluid medium and are less affected by gravity, whereas acoustic levitation is primarily concerned with overcoming gravity. Technically dynamic acoustic levitation is a form of acoustophoresis, though this term is more commonly associated with small scale acoustic tweezers. Typically sound waves at ultrasonic frequencies are used thus creating no sound audible to humans. This is primarily due to the high intensity of sound required to counteract gravity. However, there have been cases of audible frequencies being used. There are various techniques for generating the sound, but the most common is the use of piezoelectric transducers which can efficiently generate high amp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Acoustic Radiation Force Acoustic radiation force (ARF) is a physical phenomenon resulting from the interaction of an acoustic wave with an obstacle placed along its path. Generally, the force exerted on the obstacle is evaluated by integrating the acoustic radiation pressure (due to the presence of the sonic wave) over its time-varying surface. The magnitude of the force exerted by an acoustic plane wave at any given location can be calculated as: : , F^, = \frac where :, F^, is a force per unit volume, here expressed in kg/(s2cm2); :\alpha is the absorption coefficient in Np/cm (Neper/cm); :I is the temporal average intensity of the acoustic wave at the given location in W/cm2; and :c is the speed of sound in the medium in cm/s. The effect of frequency on acoustic radiation force is taken into account via intensity (higher pressures are more difficult to attain at higher frequencies) and absorption (higher frequencies have a higher absorption rate). As a reference, water has an acoustic absorp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]