A Viscoelastic Model for the Dynamic Behavior of Saturated Poroelastic Soils

1992 ◽  
Vol 59 (1) ◽  
pp. 128-135 ◽  
Author(s):  
J. P. Bardet
Keyword(s):  
Elastic Moduli ◽  
Viscoelastic Model ◽  
Degree Of Saturation ◽  
Biot Theory ◽  
One Dimensional ◽  
Poroelastic Materials ◽  
Proposed Model ◽  
Wide Range ◽  
Dynamic Loadings ◽  
The One

A viscoelastic model is proposed to describe the dynamic response of the saturated poroelastic materials that obey the Biot theory (1956). The viscoelastic model is defined from the velocity and attenuation of dilatational and distortional waves in poroelastic materials. Its material properties are defined in terms of the elastic moduli, porosity, specific gravity, degree of saturation, and permeability of the soils. The proposed model is tested by comparing its response with the one of poroelastic materials in the case of axial and lateral harmonic loadings of one-dimensional columns. The viscoelastic model is simpler to use than poroelastic materials but yields similar results for a wide range of soils and dynamic loadings.

scholarly journals Plane thermonuclear detonation waves initiated by proton beams and quasi-one-dimensional model of fast ignition

2014 ◽  
Vol 33 (1) ◽  
pp. 65-80 ◽  
Author(s):  
Alexander A. Charakhch'yan ◽  
Konstantin V. Khishchenko
Keyword(s):  
Detonation Wave ◽  
Fusion Reaction ◽  
Plasma Heating ◽  
Symmetry Plane ◽  
Detonation Waves ◽  
Proton Beams ◽  
One Dimensional ◽  
Wide Range ◽  
The One ◽  
Α Particles

AbstractThe one-dimensional problem on bilatiral irradiation by proton beams of the plane layer of condensed DT mixture with length 2H and density ρ0 ≤ 100ρs, where ρs is the fuel solid-state density at atmospheric pressure and temperature of 4 K, is considered. The proton kinetic energy is 1 MeV, the beam intensity is 1019 W/cm2 and duration is 50 ps. A mathematical model is based on the one-fluid two-temperature hydrodynamics with a wide-range equation of state of the fuel, electron and ion heat conduction, DT fusion reaction kinetics, self-radiation of plasma and plasma heating by α-particles. If the ignition occurs, a plane detonation wave, which is adjacent to the front of the rarefaction wave, appears. Upon reflection of this detonation wave from the symmetry plane, the flow with the linear velocity profile along the spatial variable x and with a weak dependence of the thermodynamic functions of x occurs. An appropriate solution of the equations of hydrodynamics is found analytically up to an arbitrary constant, which can be chosen so that the analytical solution describes with good accuracy the numerical one. The gain with respect to the energy of neutrons G ≈ 200 at Hρ0 ≈ 1 g/cm2, and G > 2000 at Hρ0 ≈ 5 g/cm2. To evaluate the ignition energy Eig of cylindrical targets, the quasi-1D model, limiting trajectories of α-particles by a cylinder of a given radius, is suggested. The model reproduces the known theoretical dependence Eig ~ ρ0−2 and gives Eig = 160 kJ for ρ0 = 100ρs ≈ 22 g/cm3.

scholarly journals THE ONE-DIMENSIONAL WAVE SPECTRA AT LIMITED FETCH

1972 ◽  
Vol 1 (13) ◽  
pp. 13
Author(s):  
Hisashi Mitsuyasu
Keyword(s):  
Similarity Theory ◽  
Wind Waves ◽  
Laboratory Data ◽  
Peak Frequency ◽  
Wave Spectra ◽  
One Dimensional ◽  
Wide Range ◽  
Laboratory Tank ◽  
The One ◽  
Dimensional Wave

The data for the spectra of wind-generated waves measured in a laboratory tank and in a bay are analyzed using the similarity theory of Kitaigorodski, and the one-dimensional spectra of fetch-limited wind waves are determined from the data. The combined field and laboratory data cover such a wide range of dimensionless fetch F (= gF/u2 ) as F : 102 ~ 10 . The fetch relations for the growthes of spectral peak frequency u)m and of total energy E of the spectrum are derived from the proposed spectra, which are consistent with those derived directly from the measured spectra.

scholarly journals Rare temperature histories and cirrus ice number density in a parcel and a one-dimensional model

2014 ◽  
Vol 14 (23) ◽  
pp. 13013-13022 ◽  
Author(s):  
D. M. Murphy
Keyword(s):  
Temperature Dependence ◽  
Low Temperatures ◽  
Ice Crystals ◽  
Strong Increase ◽  
Number Density ◽  
Dimensional Model ◽  
One Dimensional ◽  
Slow Growth Rate ◽  
Wide Range ◽  
The One

Abstract. A parcel and a one-dimensional model are used to investigate the temperature dependence of ice crystal number density. The number of ice crystals initially formed in a cold cirrus cloud is very sensitive to the nucleation mechanism and the detailed history of cooling rates during nucleation. A possible small spread in the homogeneous freezing threshold due to varying particle composition is identified as a sensitive nucleation parameter. In a parcel model, the slow growth rate of ice crystals at low temperatures inherently leads to a strong increase in ice number density at low temperatures. This temperature dependence is not observed. The model temperature dependence occurs for a wide range of assumptions and for either homogeneous or, less strongly, heterogeneous freezing. However, the parcel model also shows that random temperature fluctuations result in an extremely wide range of ice number densities. A one-dimensional model is used to show that the rare temperature trajectories resulting in the lowest number densities are disproportionately important. Low number density ice crystals sediment and influence a large volume of air. When such fall streaks are included, the ice number becomes less sensitive to the details of nucleation than it is in a parcel model. The one-dimensional simulations have a more realistic temperature dependence than the parcel mode. The one-dimensional model also produces layers with vertical dimensions of meters even if the temperature forcing has a much broader vertical wavelength. Unlike warm clouds, cirrus clouds are frequently surrounded by supersaturated air. Sedimentation through supersaturated air increases the importance of any process that produces small numbers of ice crystals. This paper emphasizes the relatively rare temperature trajectories that produce the fewest crystals. Other processes are heterogeneous nucleation, sedimentation from the very bottom of clouds, annealing of disordered to hexagonal ice, and entrainment.

A Linear Stability Analysis for an Improved One-Dimensional Two-Fluid Model

2003 ◽  
Vol 125 (2) ◽  
pp. 387-389 ◽  
Author(s):  
Jin Ho Song
Keyword(s):  
Stability Analysis ◽  
Linear Stability ◽  
Linear Stability Analysis ◽  
Fluid Model ◽  
Two Phase ◽  
One Dimensional ◽  
Proposed Model ◽  
Two Fluid Model ◽  
The One ◽  
Two Fluid

A linear stability analysis is performed for a two-phase flow in a channel to demonstrate the feasibility of using momentum flux parameters to improve the one-dimensional two-fluid model. It is shown that the proposed model is stable within a practical range of pressure and void fraction for a bubbly and a slug flow.

A predictive combustion model for one-dimensional gasoline engine simulation

2020 ◽  
pp. 146808742094590
Author(s):  
Yoshihiro Nomura ◽  
Seiji Yamamoto ◽  
Makoto Nagaoka ◽  
Stephan Diel ◽  
Kenta Kurihara ◽  
...  
Keyword(s):  
Gasoline Engine ◽  
Early Stage ◽  
Burning Velocity ◽  
Turbulent Flame ◽  
Operating Conditions ◽  
Combustion Model ◽  
One Dimensional ◽  
Turbulent Reynolds Number ◽  
Proposed Model ◽  
Wide Range

A new predictive combustion model for a one-dimensional computational fluid dynamics tool in the multibody dynamics processes of gasoline engines was developed and validated. The model consists of (1) a turbulent burning velocity model featuring a flame radius–based transitional function, steady burning velocity that considers local quenching using the Karlovitz number and laminarization by turbulent Reynolds number, as well as turbulent flame thickness and its quenching model near the liner wall, and (2) a knock model featuring auto-ignition by the Livengood–Wu integration and ignition delay time obtained using a full-kinetic model. The proposed model and previous models were verified under a wide range of operating conditions using engines with widely different specifications. Good agreement was only obtained for combustion characteristics by the proposed model without requiring individual calibration of model constants. The model was also evaluated for utilization after prototyping. Improved accuracy, especially of ignition timing, was obtained after further calibration using a small amount of engine data. It was confirmed that the proposed model is highly accurate at the early stage of the engine development process, and is also applicable for engine calibration models that require higher accuracy.

Analytical Solution of 1-D Viscoelastic Consolidation of Soft Soils with Fractional Maxwell Model

2012 ◽  
Vol 157-158 ◽  
pp. 419-423
Author(s):  
Ya Peng Zhang ◽  
Feng Gao
Keyword(s):  
Analytical Solution ◽  
Soft Soil ◽  
Soil Layer ◽  
Viscoelastic Model ◽  
Integral Form ◽  
Maxwell Model ◽  
One Dimensional ◽  
The Laplace Transform ◽  
Fractional Maxwell Model ◽  
The One

Considering the rheological characteristics of soil, think the fractional maxwell with viscoelastic model can be described, the fractional maxwell model into integral form of saturated soft soil layer, the one dimensional compression, through the Laplace transform problems get instantaneous loading and single stage, the analytical solution of the loading conditions.

NUMERICAL STUDIES ON THE VIBRATIONAL SPECTRUM OF FIBONACCI CHAIN: A MULTIFRACTAL ANALYSIS

1991 ◽  
Vol 05 (05) ◽  
pp. 825-841 ◽  
Author(s):  
WLODZIMIERZ SALEJDA
Keyword(s):  
Vibrational Spectrum ◽  
Multifractal Analysis ◽  
Scaling Laws ◽  
Model Parameters ◽  
Local Scaling ◽  
One Dimensional ◽  
Dynamic Matrix ◽  
Numerical Studies ◽  
Wide Range ◽  
The One

A harmonic Hamiltonian modelling the lattice dynamics of the one-dimensional Fibonacci-type quasicrystal is studied numerically. The multifractal analysis of vibrational spectrum is performed. It is found that the integrated normalized density of states [Formula: see text], where x denotes the square of the eigenenergy of the dynamic matrix, exhibits a finite range of scaling indices α (i.e. α min ≤α≤ α max ) describing the local scaling laws of [Formula: see text]. The α-f spectra and the Renyi dimensions [Formula: see text] are calculated in a wide range of model parameters taking into account the next-nearest-neighbour (NNN) interactions of atoms. In particular, we have observed that: (1) The α-f spectra are smooth in the interval [Formula: see text]; (2) If the so-called parameter of quasi-periodicity Q increases, then αmin and the fractal dimension of vibrational spectra [Formula: see text] decrease; (3) If the strength of NNN interactions h grows then α min decreases but D increases.

scholarly journals Kompiuterinis biojutiklių su perforuota ir selektyvia membrana modeliavimas vienmačiu keturių sluoksnių modeliu

2009 ◽  
Vol 50 ◽  
pp. 328-333
Author(s):  
Karolis Petrauskas
Keyword(s):  
Numerical Experiments ◽  
Enzymatic Reaction ◽  
Diffusion Reaction ◽  
Homogeneous Layer ◽  
Dimensional Model ◽  
One Dimensional ◽  
Proposed Model ◽  
The One ◽  
Menten Kinetic ◽  
Reaction Equations

Straipsnyje pateikiamas vienmatis biojutiklio su perforuota ir selektyvia membrana modelis. Šis modelis sudarytas pakeičiant perforuotą membraną dviem homogeniškais sluoksniais atitinkamai membranos dalims, kur skylutės yra užpildytos fermento ir kur fermento nėra. Pasiūlytas modelis buvo ištirtas vykdant skaitinius eksperimentus, kad būtų nustatytos sąlygos, kuriomis jis gali būti taikomas tiksliam biojutiklio veiksmo modeliavimui. Šio modelio tikslumas buvo vertinamas lyginant juo gaunamus rezultatus su dvimačio modelio rezultatais. Pasiūlyto modelio rezultatai taip pat buvo palyginti su vienmačio modelio, kuriame perforuota membrana pakeičiama vienu homogenišku sluoksniu, rezultatais. Biojutiklis buvo modeliuojamas reakcijos-difuzijos lygtimis su netiesiniu nariu, aprašančiu fermentinės reakcijos Michaelio–Menteno kinetiką. Modelio lygčių sistema buvo sprendžiama skaitiškai, naudojant baigtinių skirtumų metodą.Computer-Aided Modeling of a Biosensor with Selective and Perforated Membranes Using a Four-Layered One-Dimensional ModelKarolis Petrauskas SummaryThis article presents a one-dimensional model for a biosensor with perforated and selective membranes. This model is constructed by replacing the perforated membrane with two homogeneous layers. These layers are used to model parts of the perforated membrane, where holes are fi lled with an enzyme and where is no enzyme in the holes, separately. The proposed model was investigated by performing numerical experiments in order to determine conditions, under which the proposed model can be used to simulate an operation of a biosensor with an outer perforated membrane precisely. A preciseness of the model was measured by comparing its results with results of the corresponding two-dimensional model. Beside the measurement of the preciseness, results of the proposed model were compared to the results of the one-dimensional model, constructed by replacing the perforated membrane with one homogeneous layer. A biosensor was modeled using diffusion-reaction equations with a nonlinear member representing the Michaelis-Menten kinetic of an enzymatic reaction. These equations were solved numerically, using the method of fi nite differences.: 18px;"> 

scholarly journals A Mathematical Model for Transport in Poroelastic Materials with Variable Volume:Derivation, Lie Symmetry Analysis, and Examples

Symmetry ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 396
Author(s):  
Roman Cherniha ◽  
Joanna Stachowska-Pietka ◽  
Jacek Waniewski
Keyword(s):  
Solute Transport ◽  
Lie Symmetry ◽  
Transport Processes ◽  
Experimental Investigations ◽  
One Dimensional ◽  
Poroelastic Media ◽  
Poroelastic Materials ◽  
Dimensional Version ◽  
The One ◽  
Symmetry Method

Fluid and solute transport in poroelastic media is studied. Mathematical modeling of such transport is a complicated problem because of the volume change of the specimen due to swelling or shrinking and the transport processes are nonlinearly linked. The tensorial character of the variables adds also substantial complication in both theoretical and experimental investigations. The one-dimensional version of the theory is less complex and may serve as an approximation in some problems, and therefore, a one-dimensional (in space) model of fluid and solute transport through a poroelastic medium with variable volume is developed and analyzed. In order to obtain analytical results, the Lie symmetry method is applied. It is shown that the governing equations of the model admit a non-trivial Lie symmetry, which is used for construction of exact solutions. Some examples of the solutions are discussed in detail.

Revising the Kano model for designing an employee compensation system

2019 ◽  
Vol 32 (1) ◽  
pp. 78-91
Author(s):  
Hossein Vaez Shahrestani ◽  
Arash Shahin ◽  
Hadi Teimouri ◽  
Ali Shaemi Barzoki
Keyword(s):  
Design Methodology ◽  
Compensation System ◽  
Kano Model ◽  
Employee Compensation ◽  
Content Type ◽  
One Dimensional ◽  
Compensation Systems ◽  
Proposed Model ◽  
The One

Purpose The purpose of this paper is twofold: first, to revise the Kano model with a focus on one-dimensional attributes; and second, to use the revised model for categorizing and prioritizing various employee compensation strategies. Design/methodology/approach The Kano evaluation table has been revised and the one-dimensional attribute has been further extended to three categories of OO, OM and OA. In the next step, the literature review-based identified strategies have been categorized and prioritized according to the developed Kano model. Consequently, an employee compensation system has been proposed to a process-based manufacturing company as a case study. Findings Findings indicated that out of the 44 employee compensation strategies, typically 6 were must-be, 13 were one-dimensional, 18 were attractive and 7 were indifferent. Also, the results of the revised Kano model indicated that typically out of the 13 one-dimensional strategies, 7 were one-dimensional tending toward must-be (OM); and 6 were one-dimensional tending toward attractive (OA). Research limitations/implications The case study was limited to one company. The validity of the proposed model can be further studied in a larger population. This study provides managers with a more accurate instrument of decision making in selecting more differentiated employee compensation strategies, which, in turn, might lead to more employee satisfaction. Originality/value Theoretically, this study is different from existing studies, since almost none of the previous studies extended the Kano evaluation table for one-dimensional attributes. Practically, this study is another evidence of the application of the Kano model in the field of human resource management and in particular contributes to the design of employee compensation systems.

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