Longitudinal acoustic wave

The propagation of longitudinal acoustic waves in choked nozzles has been analyzed on the basis of the one-dimensional, time-dependent forms of equations (4-45) and (4-46) by introducing linearizations of the previously indicated type (for example, p = p(l + p )] for the stream wise velocity v as well—that is, v — v(l + i )—and by allowing the mean quantities p, p, and V to vary with the streamwise distance z through the nozzle, in a manner presumed known from a quasi-one-dimensional, steady-flow nozzle analysis [20]. The perturbation equations... 

LA longitudinal acoustic (wave) MOeVD metal-organic chemical vapor... 

When air in a room is disturbed by a person speaking the molecules of the air have movements that are along the path of the wave. If you were to draw a line from the speaker s mouth to your ear, the movement of the molecules would be along this line. This type of wave, called an acoustical wave, is said to be longitudinal. The pleasant sounds of music are produced by acoustical waves. On the other hand, destruction by a bomb blast also is caused by acoustical waves. Instead of oscillating up and down, molecules in the acoustical (or compression) wave bunch together as the wave passes. It is not a transverse wave. 

In a homogeneous isotropic elastic medium it is possible to split acoustic waves in independent longitudinal and transverse waves, each travelling at a speed cL and cT, respectively. As 2 is greater than or equal to zero, cT is lower than or equal to cl/ J2. 

Chan, K. H. and Bertoni, H. L. (1991). Ray representation of longitudinal lateral waves in acoustic microscopy. IEEE Trans. UFFC 38,27-34. [118,119]... 

DEBYE-SEARS EFFECT. A piezoelectric crystal vibrating in a longitudinal mode in a liquid sets up acoustic waves consisting of regions of compression and regions of rarefaction in the liquid, which alternate at... 

According to Eq. (II.7), co = 0 for k = 0 in the center of BZ 1. With these values Eqs. (II. 1)—(II.3) lead to the relation UA = UB. This means that both sets of atoms vibrate with the same amplitude and in phase (because they have the same sign). A translation of the whole chain results which corresponds to an acoustical wave with X = °°. This is called a longitudinal acoustical branch (LA). 

As shown in Fig. 4.19, in anisotropic medium, a surface acoustic wave represents a combined longitudinal (4.19a) and shear (4.19b) motion of the lattice in the y-(0)-z plane this is the saggital plane. In anisotropic media, in certain multilayer structures and at some interfaces, the surface wave velocity exceeds the velocity of the shear wave and the energy continuously leaks from the surface to the bulk of the material. In such cases, we talk about pseudo- or leaky waves. Various energy-loss... 

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