scholarly journals Time evolution approach to steady state

2016 ◽  
Vol 6 ◽  
pp. 461-467
Author(s):  
A. Muriel
Keyword(s):  
Steady State ◽  
Time Evolution ◽  
Approach To Steady State ◽  
Evolution Approach

Historical Background

2018 ◽  
Author(s):  
Klaus Morawetz
Keyword(s):  
Steady State ◽  
Kinetic Theory ◽  
Time Evolution ◽  
Historical Development ◽  
Historical Background ◽  
Quantum Kinetic Theory ◽  
Dense Gases ◽  
Nonequilibrium Phenomena ◽  
Quantum Liquids ◽  
Nonlocal Quantum

The historical development of kinetic theory is reviewed with respect to the inclusion of virial corrections. Here the theory of dense gases differs from quantum liquids. While the first one leads to Enskog-type of corrections to the kinetic theory, the latter ones are described by quasiparticle concepts of Landau-type theories. A unifying kinetic theory is envisaged by the nonlocal quantum kinetic theory. Nonequilibrium phenomena are the essential processes which occur in nature. Any evolution is built up of involved causal networks which may render a new state of quality in the course of time evolution. The steady state or equilibrium is rather the exception in nature, if not a theoretical abstraction at all.

Unsteady convective exchange flows in cavities

1998 ◽  
Vol 368 ◽  
pp. 127-153 ◽  
Author(s):  
J. J. STURMAN ◽  
G. N. IVEY
Keyword(s):  
Boundary Layer ◽  
Steady State ◽  
Boundary Layer Thickness ◽  
Buoyancy Flux ◽  
Exchange Flow ◽  
Flushing Time ◽  
Exchange Flows ◽  
Buoyancy Forcing ◽  
Convective Exchange ◽  
Approach To Steady State

Horizontal exchange flows driven by spatial variation of buoyancy fluxes through the water surface are found in a variety of geophysical situations. In all examples of such flows the timescale characterizing the variability of the buoyancy fluxes is important and it can vary greatly in magnitude. In this laboratory study we focus on the effects of this unsteadiness of the buoyancy forcing and its influence on the resulting flushing and circulation processes in a cavity. The experiments described all start with destabilizing forcing of the flows, but the buoyancy fluxes are switched to stabilizing forcing at three different times spanning the major timescales characterizing the resulting cavity-scale flows. For destabilizing forcing, these timescales are the flushing time of the region of forcing, and the filling-box timescale, the time for the cavity-scale flow to reach steady state. When the forcing is stabilizing, the major timescale is the time for the fluid in the exchange flow to pass once through the forcing boundary layer. This too is a measure of the time to reach steady state, but it is generally distinct from the filling-box time. When a switch is made from destabilizing to stabilizing buoyancy flux, inertia is important and affects the approach to steady state of the subsequent flow. Velocities of the discharges from the end regions, whether forced in destabilizing or stabilizing ways, scaled as u∼(Bl)1/3 (where B is the forcing buoyancy flux and l is the length of the forcing region) in accordance with Phillips' (1966) results. Discharges with destabilizing and stabilizing forcing were, respectively, Q−∼(Bl)1/3H and Q+∼(Bl)1/3δ (where H is the depth below or above the forcing plate and δ is the boundary layer thickness). Thus Q−/Q+>O(1) provided H>O(δ), as was certainly the case in the experiments reported, demonstrating the overall importance of the flushing processes occurring during periods of cooling or destabilizing forcing.

Signal strength in subsecond FLASH magnetic resonance imaging: The dynamic approach to steady state

1990 ◽  
Vol 17 (6) ◽  
pp. 1004-1010 ◽  
Author(s):  
W. Hänicke ◽  
K. D. Merboldt ◽  
D. Chien ◽  
M. L. Gyngell ◽  
H. Bruhn ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Steady State ◽  
Magnetic Resonance ◽  
Signal Strength ◽  
Resonance Imaging ◽  
Dynamic Approach ◽  
Approach To Steady State

Numerical Solution of the Planar Hydrostatic Foil Bearing

1979 ◽  
Vol 101 (1) ◽  
pp. 86-91 ◽  
Author(s):  
A. Eshel
Keyword(s):  
Steady State ◽  
Film Thickness ◽  
Computer Program ◽  
Numerical Solution ◽  
Asymptotic Approach ◽  
State Problem ◽  
Shooting Technique ◽  
Foil Bearing ◽  
Approach To Steady State ◽  
Steady State Problem

The steady state problem of the planar hydrostatic foil bearing is analyzed and solved numerically. Two techniques of solution are used. One method is simulation in time with asymptotic approach to steady state. This is achieved by a preprocessor which automatically sets up the numerical computer program. The second method is an iterative shooting technique. The results agree well with one another. Curves of pressure and typical film thickness versus flow are presented.

A new approach to steady state analysis of nonlinear electrical circuits

2017 ◽  
Vol 36 (3) ◽  
pp. 716-728 ◽  
Author(s):  
Tadeusz Sobczyk ◽  
Michał Radzik
Keyword(s):  
Steady State ◽  
Periodic Solutions ◽  
Nonlinear Differential Equations ◽  
Direct Calculation ◽  
Electrical Circuits ◽  
Steady State Analysis ◽  
Content Type ◽  
The Time Domain ◽  
Approach To Steady State ◽  
State Analysis

Purpose The purpose of this study is to identify a novel methodology for direct calculation of steady-state periodic solutions for electrical circuits described by nonlinear differential equations, in the time domain. Design/methodology/approach An iterative algorithm was created to determine periodic steady-state solutions for circuits with nonlinear elements in a chosen set of time instants. Findings This study found a novel differential operator for periodic functions and its application in the steady-state analysis. Research limitations/implications This approach can be extended to the determination of two- or multi-periodic solutions of nonlinear dynamic systems. Practical implications The complexity of the steady-state analysis can be reduced in comparison with the frequency-domain approach. Originality/value This study identified novel difference equations for direct steady-state analysis of nonlinear electrical circuits.

scholarly journals An Approximate Analytical Approach to Steady State Simulation of Unglazed Solar Collectors

2014 ◽  
Vol 48 ◽  
pp. 28-36 ◽  
Author(s):  
Luigi P.M. Colombo ◽  
Cesare M. Joppolo ◽  
Luca Molinaroli ◽  
Elisa Rovelli
Keyword(s):  
Steady State ◽  
Analytical Approach ◽  
Solar Collectors ◽  
Steady State Simulation ◽  
Approach To Steady State
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