Surface/interface effect on the propagation of high-frequency SH surface waves in an ultra-thin FGP over-layer bonded to a substrate

AbstractThe classical Schlichting boundary layer theory is extended to account for the excitation of generalized surface waves in the frequency and velocity amplitude range commonly used in microfluidic applications, including Rayleigh and Sezawa surface waves and Lamb, flexural and surface-skimming bulk waves. These waves possess longitudinal and transverse displacements of similar magnitude along the boundary, often spatiotemporally out of phase, giving rise to a periodic flow shown to consist of a superposition of classical Schlichting streaming and uniaxial flow that have no net influence on the flow over a long period of time. Correcting the velocity field for weak but significant inertial effects results in a non-vanishing steady component, a drift flow, itself sensitive to both the amplitude and phase (prograde or retrograde) of the surface acoustic wave propagating along the boundary. We validate the proposed theory with experimental observations of colloidal pattern assembly in microchannels filled with dilute particle suspensions to show the complexity of the boundary layer, and suggest an asymptotic slip boundary condition for bulk flow in microfluidic applications that are actuated by surface waves.

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Application Of Elastic Layers To Register Pressure Field On The Model Surface In Supersonic Flow

Siberian Journal of Physics ◽

10.54362/1818-7919-2016-11-1-23-33 ◽

2016 ◽

Vol 11 (1) ◽

pp. 23-33

Author(s):

Maxim Golubev ◽

Andrey Shmakov

Keyword(s):

Surface Waves ◽

High Frequency ◽

High Speed ◽

Pressure Pulsation ◽

Pressure Field ◽

Leading Edge ◽

Supersonic Wind Tunnel ◽

Register Pressure ◽

Elastic Layers ◽

Sharp Leading Edge

The work presents the results of application of panoramic interferential technique which is based on elastic layers (sensors) usage to obtain pressure distribution on the flat plate having sharp leading edge. Experiments were done in supersonic wind tunnel at Mach number M = 4. Sensitivity and response time are shown to be enough to register pressure pulsation against standing and traveling sensor surface waves. Applying high-frequency image acquiring is demonstrated to make possible to distinguish at visualization images high-speed disturbances propagating in the boundary layer from low-speed surface waves

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Seismic imaging at a mineral-deposit scale using high-frequency surface waves (0.5–24 Hz) in ambient noise wavefield

10.3997/2214-4609.202089007 ◽

2020 ◽

Author(s):

Y. Xu ◽

S. Lebedev ◽

R. Bonadio ◽

T. Meier ◽

C. Bean ◽

...

Keyword(s):

Surface Waves ◽

High Frequency ◽

Ambient Noise ◽

Seismic Imaging ◽

Mineral Deposit

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Fundamental properties of surface waves in lossless stratified structures

Proceedings of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rspa.2009.0664 ◽

2010 ◽

Vol 466 (2120) ◽

pp. 2447-2469 ◽

Cited By ~ 19

Author(s):

Guido Valerio ◽

David R. Jackson ◽

Alessandro Galli

Keyword(s):

Surface Waves ◽

Dispersion Equation ◽

High Frequency ◽

Low Frequency ◽

Layered Structures ◽

Graphical Solution ◽

Fundamental Properties ◽

The Past ◽

Permittivity And Permeability ◽

Constitutive Parameters

This paper is focused on dispersive properties of lossless planar layered structures with media having positive constitutive parameters (permittivity and permeability), possibly uniaxially anisotropic. Some of these properties have been derived in the past with reference to specific simple layered structures, and are here established with more general proofs, valid for arbitrary layered structures with positive parameters. As a first step, a simple application of the Smith chart to the relevant dispersion equation is used to prove that evanescent (or plasmonic-type) waves cannot be supported by layers with positive parameters. The main part of the paper is then focused on a generalization of a common graphical solution of the dispersion equation, in order to derive some general properties about the behaviour of the wavenumbers of surface waves as a function of frequency. The wavenumbers normalized with respect to frequency are shown to be always increasing with frequency, and at high frequency they tend to the highest refractive index in the layers. Moreover, two surface waves with the same polarization cannot have the same wavenumber at a given frequency. The low-frequency behaviours are also briefly addressed. The results are derived by means of a suitable application of Foster’s theorem.

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A 108km2 Compressive Sensing Processing Trial

10.2118/207599-ms ◽

2021 ◽

Author(s):

Dustin Blymyer ◽

Klaas Koster ◽

Graeme Warren

Keyword(s):

Compressive Sensing ◽

Surface Waves ◽

Seismic Data ◽

High Frequency ◽

Quality Data ◽

Low Velocity ◽

Conventional Design ◽

Seismic Acquisition ◽

Similar Cost ◽

Station Density

Abstract Summary Compressive sensing (CS) of seismic data is a new style of seismic acquisition whereby the data are recorded on a pseudorandom grid rather than along densely sampled lines in a conventional design. A CS design with a similar station density will generally yield better quality data at a similar cost compared to a conventional design, whereas a CS design with a lower station density will reduce costs while retaining quality. Previous authors (Mosher, 2014) have shown good results from CS surveys using proprietary methods for the design and processing. In this paper we show results obtained using commercially available services based on published algorithms (Lopez, 2016). This is a necessary requirement for adoption of CS by our industry. This report documents the results of a 108km2 CS acquisition and processing trial. The acquisition and processing were specifically designed to establish whether CS can be used for suppression of backscattered, low velocity, high frequency surface waves. We demonstrate that CS data can be reconstructed by a commercial contractor and that the suppression of backscattered surface waves is improved by using CS receiver gathers reconstructed to a dense shot grid. We also show that CS acquisition is a reliable alternative to conventional acquisition from which high-quality subsurface images can be formed.

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