Some approximations of use in predicting the behavior of a PCM cylinder array

Fully anisotropic problems are found where the radiative interaction is due to small-scale elements that lack spherical symmetry, for example: fibrous insulation, finned heat sinks, plant canopies, and some solar energy absorbers. We present the effective bulk optical properties of a PM composed of small-scale opaque cylinders. The properties are derived from data generated by detailed Monte-Carlo numerical experiments. The data reduction procedure is relatively simple and does not require a full solution and optimization of the Radiative Transfer Equation. Benchmark cases are presented, comparing an exact solution (with geometric detail of the cylinder array) and an approximate solution using a continuous PM model with the effective volumetric properties.

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Envelope grinding of micro-cylinder array lenses using a near arc-profile wheel without on-machine precision truing

Journal of Materials Processing Technology ◽

10.1016/j.jmatprotec.2020.116927 ◽

2021 ◽

Vol 289 ◽

pp. 116927

Author(s):

Wei Wang ◽

Zhen Zhang ◽

Peng Yao ◽

Xiangyu Wang ◽

Zongbo Zhang ◽

...

Keyword(s):

Machine Precision ◽

Cylinder Array

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Nonlinear Wave Loads Acting on Cylinder Array Slowly Oscillating in Diffraction and Radiation Wave Fields

24th International Conference on Offshore Mechanics and Arctic Engineering: Volume 1, Parts A and B ◽

10.1115/omae2005-67363 ◽

2005 ◽

Author(s):

Weiguang Bao ◽

Takeshi Kinoshita ◽

Motoki Yoshida

Keyword(s):

Nonlinear Wave ◽

Perturbation Expansion ◽

Low Frequency ◽

Added Mass ◽

Wave Loads ◽

Wave Fields ◽

Wave Drift ◽

Cylinder Array ◽

Radiation Wave ◽

Low Frequency Motion

The problem of a circular cylinder array slowly oscillating in both diffraction and radiation wave fields is considered in the present work. As a result of the interaction between the wave fields and the low-frequency motion, nonlinear wave loads may be separated into the so-called wave-drift added mass and damping. They are force components proportional to the square of the wave amplitude but in phase of the acceleration and velocity of the low-frequency motion respectively. The frequency of the slow oscillation is assumed to be much smaller than the wave frequency. Perturbation expansion based on two time scales and two small parameters is performed to the order to include the effects of the acceleration of the low-frequency motion. Solutions to these higher order potentials are suggested in the present work. Wave loads including the wave drift added mass and damping are evaluated by the integration of the hydrodynamic pressure over the instantaneous wetted body surface.

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