Low-Frequency Scattering by Correlated Distributions of Randomly Oriented Particles
Low-Frequency Scattering by Correlated Distributions of Randomly Oriented Particles
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随机定向粒子相关分布的低频散射
DOI：
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发表时间：
1987
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通讯作者：
V. Twersky
中科院分区：
文献类型：
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作者：
V. Twersky
考虑了在取向上平均的相关散射体的随机分布，对应于统计力学粒子的各向同性流体（具有体积v，数浓度ρ和体积分数w = ρ v）。对于与波长和接近嵌入介质的声学粒子参数相比小的中心的最小分离，来自单位体积的非相干微分散射和相应的衰减系数与数量浓度的波动（方差）成比例。对于任意凸形硬颗粒（例如，椭圆形或简单多面体，在接触处排斥），其形状参数c ≥ 3，方差用w中多项式的商S（c; w）表示，其在w（c）处具有最大值S（c）。之前考虑了球体（c = 3）。当c> 3时，涨落以及S ■和w ■都比球面小;当c <3时（我们正式考虑），它们都比球面大。结果解释比较领先的条款与第二维里系数。
Random distributions of correlated scatterers averaged over orientation are considered, corresponding to isotropic fluids of statistical mechanics particles (with volume v, number concentration ρ, and volume fraction w=ρv). For minimum separation of centers small compared to wavelength and acoustic particle parameters close to the embedding medium’s, the incoherent differential scattering from unit volume and the corresponding attenuation coefficient are proportional to the fluctuations (variance) in number concentration. For arbitrary convex hard particles (e.g., ovals or simple polyhedra, repulsive at contact) with shape parameter c≥3, the variance is expressed in terms of a quotient S(c;w) of polynomials in w that has a maximum S■(c) at w■(c). Spheres (c=3) were considered earlier. For c>3, the fluctuations and S■ and w■ are smaller than for spheres; for c<3 (which we consider formally), they are larger than for spheres. The results are interpreted by comparing leading terms with the second virial coef...