Nonlinear Scaling Laws for Parametric Receiving Arrays. Part I. Theoretical Analysis

1976 ◽  
Author(s):  
F. H. Fenlon ◽  
J. W. Kesner
Keyword(s):  
Theoretical Analysis ◽  
Scaling Laws

scholarly journals On the Buoyancy Subrange in Stratified Turbulence

Atmosphere ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 659
Author(s):  
Victor Avsarkisov
Keyword(s):  
Energy Spectrum ◽  
Theoretical Analysis ◽  
Potential Energy ◽  
Froude Number ◽  
Scaling Laws ◽  
Turbulent Flux ◽  
Geophysical Flows ◽  
Energy Spectra ◽  
Stratified Turbulence ◽  
Buoyancy Subrange

This study is motivated by the importance of the stratified turbulence in geophysical flows. We present a theoretical analysis of the buoyancy subrange based on the theory of strongly stratified turbulence. Some important turbulent scales and their relations are explored. Scaling constants of the buoyancy subrange scaling laws for both kinetic and potential energy spectra are derived and analyzed. It is found that these constants are functions of the horizontal Froude number F r h . For the potential energy spectrum, the scaling constant also depends on the turbulent flux coefficient of Γ .

Shape and scaling of the mean-velocity profile in thermally-stratified plane-Couette flows

2021 ◽  
Author(s):  
Dongrong Zhang
Keyword(s):  
Theoretical Analysis ◽  
Velocity Profile ◽  
Turbulent Flows ◽  
Intermediate Layer ◽  
Scaling Laws ◽  
Similarity Theory ◽  
Constant Density ◽  
Mean Velocity ◽  
The Mean

Abstract It has long been known from measurements that buoyant motions cause the mean-velocity profile (MVP) in thermally-stratified, wall-bounded turbulent flows to significantly deviate from its constant-density counterpart. Theoretical analysis has restricted attention to an “intermediate layer” of the MVP, akin to the celebrated “log layer” in the constant-density case. Here, for thermally-stratified plane-Couette flows, we study the shape and scaling of the whole MVP. We elucidate the mechanisms that dictate the shape of the MVP by using the framework of the spectral link (Gioia et al.; 2010), and obtain scaling laws for the whole MVP by generalizing the Monin-Obukhov similarity theory.

Acoustically Generated Micromachined Jet Arrays for Micropropulsion Applications

2002 ◽  
Author(s):  
Michael O. Mu¨ller ◽  
Luis P. Bernal ◽  
Peter D. Washabaugh ◽  
Tsung-Kuan A. Chou ◽  
Hanseup S. Kim ◽  
...  
Keyword(s):  
Theoretical Analysis ◽  
Scaling Laws ◽  
Experimental Results ◽  
Sound Design ◽  
Mems Devices ◽  
Reduced Order ◽  
Manufacturing Method ◽  
Electrostatically Actuated ◽  
Geometric Size ◽  
Accurate Performance

Theory, manufacturing and experimental results of acoustically generated micromachined jet arrays for micropropulsion applications are presented. A reduced order theoretical analysis is found to be an accurate performance predictor. Scaling laws derived from the theory suggest the performance benefits derived by reducing the geometric size of the resonators, specifically the application of MEMS technologies. A novel manufacturing method is employed to construct the devices, incorporating an electrostatically actuated membrane to drive the acoustic jets. Experimental results of the MEMS devices demonstrate a structurally sound design, and a performance commensurate with expectations.

scholarly journals Chirality-induced bacterial rheotaxis in bulk shear flows

2020 ◽  
Vol 6 (28) ◽  
pp. eabb2012 ◽  
Author(s):  
Guangyin Jing ◽  
Andreas Zöttl ◽  
Éric Clément ◽  
Anke Lindner
Keyword(s):  
Theoretical Analysis ◽  
Scaling Laws ◽  
Shear Flows ◽  
Kinematic Model ◽  
Marginal Stability ◽  
Complex Environments ◽  
Shear Rates ◽  
Spatially Resolved ◽  
Swimming Bacteria ◽  
Reorientation Dynamics

Interaction of swimming bacteria with flows controls their ability to explore complex environments, crucial to many societal and environmental challenges and relevant for microfluidic applications such as cell sorting. Combining experimental, numerical, and theoretical analysis, we present a comprehensive study of the transport of motile bacteria in shear flows. Experimentally, we obtain with high accuracy and, for a large range of flow rates, the spatially resolved velocity and orientation distributions. They are in excellent agreement with the simulations of a kinematic model accounting for stochastic and microhydrodynamic properties and, in particular, the flagella chirality. Theoretical analysis reveals the scaling laws behind the average rheotactic velocity at moderate shear rates using a chirality parameter and explains the reorientation dynamics leading to saturation at large shear rates from the marginal stability of a fixed point. Our findings constitute a full understanding of the physical mechanisms and relevant parameters of bacteria bulk rheotaxis.

Siphon Flows in Stratified Coronal Loops

1994 ◽  
Vol 144 ◽  
pp. 185-187
Author(s):  
S. Orlando ◽  
G. Peres ◽  
S. Serio
Keyword(s):  
Heat Flux ◽  
Scaling Laws ◽  
Flow Model ◽  
Supersonic Flows ◽  
Coronal Loops ◽  
Characteristic Parameters

AbstractWe have developed a detailed siphon flow model for coronal loops. We find scaling laws relating the characteristic parameters of the loop, explore systematically the space of solutions and show that supersonic flows are impossible for realistic values of heat flux at the base of the upflowing leg.

Microdiffraction Patterns of Small Metallic Particles II; Theoretical Analysis

1982 ◽  
Vol 40 ◽  
pp. 668-669
Author(s):  
A. Gómez ◽  
P. Schabes-Retchkiman ◽  
M. José-Yacamán ◽  
T. Ocaña
Keyword(s):  
Experimental Data ◽  
Electron Diffraction ◽  
Theoretical Analysis ◽  
Size Range ◽  
Dynamical Theory ◽  
Metallic Particles ◽  
Splitting Effect

The splitting effect that is observed in microdiffraction pat-terns of small metallic particles in the size range 50-500 Å can be understood using the dynamical theory of electron diffraction for the case of a crystal containing a finite wedge. For the experimental data we refer to part I of this work in these proceedings.

Theoretical analysis of a monopole antenna with conducting flat disk above the earth

2001 ◽  
Vol 84 (7) ◽  
pp. 27-36
Author(s):  
Aki Yuasa ◽  
Daisuke Itatsu ◽  
Naoki Inagaki ◽  
Nobuyoshi Kikuma
Keyword(s):  
Theoretical Analysis ◽  
Monopole Antenna ◽  
The Earth ◽  
Flat Disk

Context Aversion, Pavlovian Conditioning, and the Psychological Side Effects of Chemotherapy

1997 ◽  
Vol 2 (2) ◽  
pp. 118-124
Author(s):  
Geoffrey Hall
Keyword(s):  
Animal Model ◽  
Side Effects ◽  
Theoretical Analysis ◽  
Conditioned Response ◽  
Behavioral Strategies ◽  
Contextual Cues ◽  
Anticipatory Nausea ◽  
Laboratory Rats ◽  
Anticipatory Nausea And Vomiting ◽  
Parallel Case

Patients who have undergone several sessions of chemotherapy for cancer will sometimes develop anticipatory nausea and vomiting (ANV), these unpleasant side effects occurring as the patients return to the clinic for a further session of treatment. Pavlov's analysis of learning allows that previously neutral cues, such as those that characterize a given place or context, can become associated with events that occur in that context. ANV could thus constitute an example of a conditioned response elicited by the contextual cues of the clinic. In order to investigate this proposal we have begun an experimental analysis of a parallel case in which laboratory rats are given a nausea-inducing treatment in a novel context. We have developed a robust procedure for assessing the acquisition of context aversion in rats given such training, a procedure that shows promise as a possible animal model of ANV. Theoretical analysis of the conditioning processes involved in the formation of context aversions in animals suggests possible behavioral strategies that might be used in the alleviation of ANV, and we report a preliminary experimental test of one of these.

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