Search results
Results from the WOW.Com Content Network
The collision cross section per volume or collision cross section density is , and it is related to the mean free path by l = 1 2 C σ {\displaystyle l={\frac {1}{{\sqrt {2}}C\sigma }}} Combining the kinetic equations for molecular motion with the defining equation of shear viscosity gives the well known equation for shear viscosity for dilute ...
In physics, and especially scattering theory, the momentum-transfer cross section (sometimes known as the momentum-transport cross section [1]) is an effective scattering cross section useful for describing the average momentum transferred from a particle when it collides with a target. Essentially, it contains all the information about a ...
The r* cross-correlation metric is based on the variance metrics of SSIM. It's defined as r*(x, y) = σ xy / σ x σ y when σ x σ y ≠ 0, 1 when both standard deviations are zero, and 0 when only one is zero. It has found use in analyzing human response to contrast-detail phantoms. [18] SSIM has also been used on the gradient of ...
Favre averaging is the density-weighted averaging method, used in variable density or compressible turbulent flows, in place of the Reynolds averaging.The method was introduced formally by the French physicist Alexandre Favre in 1965, [1] [2] although Osborne Reynolds had also already introduced the density-weighted averaging in 1895. [3]
In general, the scattering cross section is different from the geometrical cross section of a particle, as it depends upon the wavelength of light and the permittivity in addition to the shape and size of the particle. The total amount of scattering in a sparse medium is determined by the product of the scattering cross section and the number ...
Sometimes different reference areas are given for the same object in which case a drag coefficient corresponding to each of these different areas must be given. For sharp-cornered bluff bodies , like square cylinders and plates held transverse to the flow direction, this equation is applicable with the drag coefficient as a constant value when ...
The TKE can be defined to be half the sum of the variances σ² (square of standard deviations σ) of the fluctuating velocity components: = (+ +) = ((′) ¯ + (′) ¯ + (′) ¯), where each turbulent velocity component is the difference between the instantaneous and the average velocity: ′ = ¯ (Reynolds decomposition).
where is the volume fraction of the fibers in the composite (and is the volume fraction of the matrix).. If it is assumed that the composite material behaves as a linear-elastic material, i.e., abiding Hooke's law = for some elastic modulus of the composite and some strain of the composite , then equations 1 and 2 can be combined to give