Total reflection coefficient in glancing incidence of a light beam on a scattering medium of finite thickness with large-scale inhomogeneities

1984 ◽  
Vol 5 (1) ◽  
pp. 93-95
Author(s):  
I. A. Kuzovlev ◽  
V. S. Remizovich
Keyword(s):  
Reflection Coefficient ◽  
Light Beam ◽  
Large Scale ◽  
Finite Thickness ◽  
Total Reflection ◽  
Scattering Medium

scholarly journals PORT RESONANCE MITIGATION MODELED INTRODUCING ARJ-R STRUCTURES

2020 ◽  
pp. 38
Author(s):  
Jose A. GONZALEZ-ESCRIVA ◽  
Josep R. MEDINA ◽  
Joaquin M. GARRIDO
Keyword(s):  
Reflection Coefficient ◽  
Physical Model ◽  
Large Scale ◽  
Low Frequency ◽  
Model Tests ◽  
Wave Interference ◽  
Low Frequency Oscillations ◽  
Physical Model Tests ◽  
Similar Cost ◽  
Interference Mechanism

ARJ-R caissons are based on the "long-circuit" concept (Medina et al, 2016) that allows the extension of the destructive wave interference mechanism to mitigate low frequency oscillations without enlarging the width of the caisson. The performance of the ARJ-R caissons is referred to its reflection coefficient (Cr) which was obtained through large-scale physical model tests (Gonzalez-Escriva et al, 2018). In this paper, the effectiveness of Anti-Reflective Jarlan-type structures for Port Resonance mitigation (ARJ-R) has been assessed numerically for the port of Denia (Spain). ARJ-R structures are constructible, with similar dimensions as conventional vertical quay caissons and with a similar cost (15percent more than conventional vertical caisson).Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/LomQEVpvjik

scholarly journals Characteristics of Large-Scale Structures in Supersonic Planar Mixing Layer with Finite Thickness

2014 ◽  
Vol 6 ◽  
pp. 878679
Author(s):  
Hailong Zhang ◽  
Jiping Wu ◽  
Jian Chen ◽  
Weidong Liu
Keyword(s):  
High Speed ◽  
Large Scale ◽  
Finite Thickness ◽  
Mixing Layer ◽  
Mixing Enhancement ◽  
Laser Scattering ◽  
Large Scale Structures ◽  
Eddy Simulation ◽  
Planar Laser ◽  
Scale Structures

Nanoparticle-based planar laser scattering (NPLS) experiments and large eddy simulation (LES) were launched to get the fine structure of the supersonic planar mixing layer with finite thickness in the present study. Different from the turbulent development of supersonic planar mixing layer with thin thickness, the development of supersonic planar mixing layer with finite thickness is rapidly. The large-scale structures of mixing layer that possess the characters of quick movement and slow changes transmit to downriver at invariable speed. The transverse results show that the mixing layer is strip of right and dim and possess 3D characteristics. Meanwhile the vortices roll up from two sides to the center. Results indicate that the higher the pressure of the high speed side is, the thicker the mixing layer is. The development of mixing layer is restrained when the pressure of lower speed side is higher. The momentum thickness goes higher with the increase of the clapboard thickness. Through increasing the temperature to change the compression can affect the development of the vortices. The present study can make a contribution to the mixing enhancement and provide initial data for the later investigations.

Light beam shifts in total reflection

2006 ◽  
Vol 266 (1) ◽  
pp. 336-341 ◽  
Author(s):  
Pierre Hillion
Keyword(s):  
Light Beam ◽  
Total Reflection

scholarly journals The behaviour of scattering media in fully diffused light

1918 ◽  
Vol 94 (659) ◽  
pp. 222-237 ◽  
Keyword(s):  
Experimental Data ◽  
Finite Thickness ◽  
Scattering Medium ◽  
Scattering Media ◽  
Present Communication ◽  
Practical Standpoint ◽  
The Subject ◽  
American Society ◽  
Diffused Light ◽  
Complex Subject

The present paper is the outcome of a discussion which arose between the authors after the publication of a paper by O. Bloch and F. F. Renwick,* which dealt with the subject of the opacity of diffusing media, chiefly from the practical standpoint, and included also lengthy extracts from the Reports of a Committee of the American Society of Illuminating Engineers. On finding that we were unable to reconcile the experimental data with the theory included in the above paper, we were gradually led into the attempt to find solutions of some of the problems involved in this complex subject, starting only with the indisputable fact that when light falls upon a finite thickness of a scattering medium, part is rejected, part extinguished, and part transmitted. In the present communication we have confined ourselves to a study of the action of such media upon light which is assumed to be already completely diffused.

scholarly journals About the modeling of light beam self-focusing in plasma at the irradiation of the target by power UV laser

2021 ◽  
Vol 9 (1) ◽  
pp. 79-86
Author(s):  
I. G. Lebo
Keyword(s):  
Laser Beam ◽  
Light Beam ◽  
Large Scale ◽  
Critical Density ◽  
Calculated Data ◽  
Aluminum Foil ◽  
Thermonuclear Fusion ◽  
Uv Laser ◽  
Focusing Effect ◽  
Self Focusing

The peculiarities of light beam expansion in plasma upon irradiation of condensed targets with a powerful UV laser pulse are studied with the help of mathematical modeling. Experiments were carried out at the Lebedev Physical Institute of the Russian Academy of Sciences with the use of GARPUN installation: a powerful KrF laser that irradiated two-layer targets consisting of aluminum foil and a plexiglass layer. Channels stretched along the direction of incidence of the laser beam were found at the bottom of the crater. It was shown on the basis of experimental and calculated data that selffocusing of the laser beam developed in the plasma. As a result, hot spots were produced in vicinity of the plasma critical density, and fast (superthermal) electron flows were generated. The electron flows could produce the channels in the plexiglas. In order to describe the self-focusing effect a physicalmathematical model was developed, and “FOCUS” program was created at the Russian Technological University (MIREA). Numerical simulations were carried out on the gas-dynamic profiles (linear and exponential). It was shown that thermal self-focusing could develop at the conditions of “GARPUN” experiments (~ 1 mm longitudinal plasma, moderate radiation intensity: 1011–1012(W/cm2) × µm2).  The parameters of dangerous modes of laser beam perturbations were estimated. The interest in the experimental and mathematical modelling results is related to the laser thermonuclear fusion (LTF) research. Although Nd glass lasers are the basic installations for LTF research, UV gas eximer lasers have some advantages as drivers for future thermonuclear fusion reactors. The interaction of UV laser radiation with plasma has some peculiarities. Thus, developing physical-mathematical models and creating new programs required for the interpretation of modern UV laser – plasma coupling experiments and for the design of large scale facilities based on eximer drivers is a topical problem.

scholarly journals Reflection of acoustic waves from the boundary or layer of two-phase medium

2018 ◽  
Vol 148 ◽  
pp. 15005
Author(s):  
D.A. Gubaidullin ◽  
D.D. Gubaidullina ◽  
Yu.V. Fedorov
Keyword(s):  
Reflection Coefficient ◽  
Acoustic Wave ◽  
Acoustic Waves ◽  
Finite Thickness ◽  
Low Frequency ◽  
Bubbly Liquid ◽  
Pure Liquid ◽  
Angle Of Incidence ◽  
Two Phase ◽  
Low Frequencies

The inclined incidence of the acoustic wave on a layer of gas-droplet mixture or bubbly liquid of finite thickness is theoretically investigated. In the case of the incidence of the low-frequency acoustic wave to interface between the pure gas and aerosol or to interface between pure liquid and bubbly liquid the basic laws of reflection and transmission of a wave are established. This circumstance allows us to evaluate the transmission and reflection coefficients, depending on the volume content of inclusions and the angle of incidence of the acoustic wave. In particular, for the interface between pure gas and aerosol analytical expressions of the critical angle of wave incidence at which reflection coefficient becomes zero are obtained, i.e. thus there is a complete passage of the acoustic wave through the interface. It is established that the increase of the angle of incidence of the acoustic wave on the boundary or layer of aerosol causes: first, either to increase or to decrease of the reflection coefficient at low frequencies, and second, to appearance of additional minima depending on the reflection coefficient from frequency of disturbances related to the difference of speed of sound and density of the medium.

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