Protecting an Asynchronous NoC against Transient Channel Faults

2012 ◽  
Author(s):  
Syed Rameez Naqvi ◽  
Varadan Savulimedu Veeravalli ◽  
Andreas Steininger
Keyword(s):  
Transient Channel

Turbulence in transient channel flow

2013 ◽  
Vol 715 ◽  
pp. 60-102 ◽  
Author(s):  
S. He ◽  
M. Seddighi
Keyword(s):  
Boundary Layer ◽  
Reynolds Number ◽  
Turbulent Flow ◽  
Channel Flow ◽  
Flow Rate ◽  
Bypass Transition ◽  
Turbulent Structures ◽  
Turbulent Spots ◽  
Transient Channel ◽  
Transitional Phase

AbstractDirect numerical simulations (DNS) are performed of a transient channel flow following a rapid increase of flow rate from an initially turbulent flow. It is shown that a low-Reynolds-number turbulent flow can undergo a process of transition that resembles the laminar–turbulent transition. In response to the rapid increase of flow rate, the flow does not progressively evolve from the initial turbulent structure to a new one, but undergoes a process involving three distinct phases (pre-transition, transition and fully turbulent) that are equivalent to the three regions of the boundary layer bypass transition, namely, the buffeted laminar flow, the intermittent flow and the fully turbulent flow regions. This transient channel flow represents an alternative bypass transition scenario to the free-stream-turbulence (FST) induced transition, whereby the initial flow serving as the disturbance is a low-Reynolds-number turbulent wall shear flow with pre-existing streaky structures. The flow nevertheless undergoes a ‘receptivity’ process during which the initial structures are modulated by a time-developing boundary layer, forming streaks of apparently specific favourable spacing (of about double the new boundary layer thickness) which are elongated streamwise during the pre-transitional period. The structures are stable and the flow is laminar-like initially; but later in the transitional phase, localized turbulent spots are generated which grow spatially, merge with each other and eventually occupy the entire wall surfaces when the flow becomes fully turbulent. It appears that the presence of the initial turbulent structures does not promote early transition when compared with boundary layer transition of similar FST intensity. New turbulent structures first appear at high wavenumbers extending into a lower-wavenumber spectrum later as turbulent spots grow and join together. In line with the transient energy growth theory, the maximum turbulent kinetic energy in the pre-transitional phase grows linearly but only in terms of ${u}^{\ensuremath{\prime} } $, whilst ${v}^{\ensuremath{\prime} } $ and ${w}^{\ensuremath{\prime} } $ remain essentially unchanged. The energy production and dissipation rates are very low at this stage despite the high level of ${u}^{\ensuremath{\prime} } $. The pressure–strain term remains unchanged at that time, but increases rapidly later during transition along with the generation of turbulent spots, hence providing an unambiguous measure for the onset of transition.

Selective attenuation in brightness for brief stimuli and at low intensities supports age-related transient channel losses

1987 ◽  
Vol 13 (3) ◽  
pp. 145-149 ◽  
Author(s):  
Joseph F. Sturr ◽  
Karl Van Orden ◽  
Harvey A. Taub
Keyword(s):  
Age Related ◽  
Transient Channel

The sustained–transient channel approach to visual masking: an updated model

2006 ◽  
pp. 141-216
Author(s):  
Bruno G. Breitmeyer ◽  
Haluk ÖĞmen
Keyword(s):  
Visual Masking ◽  
Transient Channel

scholarly journals A comparative study of turbulence models in a transient channel flow

2014 ◽  
Vol 89 ◽  
pp. 111-123 ◽  
Author(s):  
S. Gorji ◽  
M. Seddighi ◽  
C. Ariyaratne ◽  
A.E. Vardy ◽  
T. O’Donoghue ◽  
...  
Keyword(s):  
Comparative Study ◽  
Channel Flow ◽  
Turbulence Models ◽  
Transient Channel

scholarly journals Transient channel incision along Bolinas Ridge, California: Evidence for differential rock uplift adjacent to the San Andreas fault

2007 ◽  
Vol 112 (F3) ◽  
Author(s):  
Eric Kirby ◽  
Courtney Johnson ◽  
Kevin Furlong ◽  
Arjun Heimsath
Keyword(s):  
San Andreas Fault ◽  
Channel Incision ◽  
San Andreas ◽  
Transient Channel

scholarly journals The Effect of Varying Viscosity in Turbulent Channel Flow

2020 ◽  
Author(s):  
Victor Coppo Leite ◽  
Elia Merzari
Keyword(s):  
Numerical Simulation ◽  
Reynolds Number ◽  
Direct Numerical Simulation ◽  
Channel Flow ◽  
Flow Profile ◽  
Streamwise Direction ◽  
Turbulent Statistics ◽  
Transient Channel ◽  
Dependent Viscosity ◽  
Varying Viscosity

Abstract In this article we examine channel flow subject to spatially varying viscosity in the streamwise direction. The Reynolds number is imposed locally with three different ramps. The setup is reminiscent of transient channel flow, but with a space-dependent viscosity rather than a time dependent viscosity. It is also relevant to various applications in nuclear engineering and in particular in test reactors, where the viscosity changes significantly in the streamwise direction, and there is a severe lack of Direct Numerical Simulation (DNS) data to benchmark turbulence models in these conditions. As part of this work we set up a novel benchmark case: the channel is extended in the stream-wise direction up to 20π. The viscosity is kept constant in the first 4π region. This inlet region is used as a cyclic region to obtain a fully developed flow profile at the beginning of the ramping region. In the ramping region the Reynolds number is linearly increased along the channel. The flow is homogenous in the spanwise direction, while it is non-homogenous in the stream-wise and wall-normal direction. We perform here Direct Numerical Simulation (DNS) with Nek5000, a spectral-element computational fluid dynamics (CFD) code developed at Argonne National Laboratory. In this study, specific focus is given to the investigation of turbulence properties and structures in the near-wall region along the flow direction. Turbulent statistics are collected and investigated. Similarly to transient channel flow, the results show that a variation in the Reynolds across a channel does not cause an immediate change in the size of turbulent structures in the ramp region and a delay is in fact observed in both wall shear and friction Reynolds number. The results from the present study are compared with a correlation available in the literature for the friction velocity and as a function of the Reynolds number.

Effects of surface roughness topography in transient channel flows

2021 ◽  
pp. 1-27
Author(s):  
Sai C. Mangavelli ◽  
Junlin Yuan ◽  
Giles J. Brereton
Keyword(s):  
Surface Roughness ◽  
Channel Flows ◽  
Transient Channel

scholarly journals Contrast gain mechanism or transient channel? Why the effects of a background pattern alter over time

2001 ◽  
Vol 41 (15) ◽  
pp. 1879-1883 ◽  
Author(s):  
Robert J. Snowden
Keyword(s):  
Contrast Gain ◽  
Transient Channel ◽  
Over Time ◽  
Background Pattern

Algorithmic and System Approaches for a Stable LiFi-RF HetNet Under Transient Channel Conditions

2021 ◽  
Author(s):  
Hansini Vijayaraghavan ◽  
Anna Prado ◽  
Thomas Wiese ◽  
Wolfgang Kellerer
Keyword(s):  
Channel Conditions ◽  
Transient Channel ◽  
System Approaches
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