|
Rayleigh Criterion
Rayleigh criterion may refer to: * , optical angular resolution * , instability criterion in Taylor–Couette flow * Rayleigh roughness criterion, surface roughness criterion in optics * Rayleigh criterion (thermo-acoustic instability), criterion for thermo-acoustic instability * Rayleigh–Kuo criterion {{Disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rayleigh Roughness Criterion
Gloss is an optical property which indicates how well a surface reflects light in a specular (mirror-like) direction. It is one of the important parameters that are used to describe the visual appearance of an object. Other categories of visual appearance related to the perception of regular or diffuse reflection and transmission of light have been organized under the concept of '' cesia'' in an order system with three variables, including gloss among the involved aspects. The factors that affect gloss are the refractive index of the material, the angle of incident light and the surface texture. Apparent gloss depends on the amount of ''specular'' reflection – light reflected from the surface in an equal amount and the symmetrical angle to the one of incoming light – in comparison with ''diffuse'' reflection – the amount of light scattered into other directions. Theory When light illuminates an object, it interacts with it in a number of ways: * Absorbed within it (large ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rayleigh Criterion (thermo-acoustic Instability)
Thermo-acoustic instability refers to an instabiltiy arising due to acoustics field and unsteady heat release process. This instability is very relevant in combustion instabilities in systems such as rocket engines, etc.Williams, F. A. (2018). Combustion theory. CRC Press. Rayleigh criterion A very simple mechanism of acoustic amplification was first identified by Lord Rayleigh in 1878.Rayleigh, J. W. S. B. (1896). The theory of sound (Vol. 2). Macmillan. In simple terms, Rayleigh criterion states that ''amplification results if, on the average, heat addition occurs in phase with the pressure increases during the oscillation''.. That is, if p' is the pressure perturbation (with respect to its mean value \langle p\rangle) and \dot q' is the rate of heat release per unit volume (with respect to its mean value \langle \dot q\rangle), then the Rayleigh criterion says that acoustic amplification occurs if \langle p' \dot q' \rangle >0. Rayleigh criterion is used to many explain pheno ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
