# the critical point of the transition to turbulence in pipe

### [1709.03738] Transition to turbulence in pulsating pipe flow

Sep 12,2017 the critical point of the transition to turbulence in pipe#0183;The transition point predicted in the zero $\alpha$ limit equals to the critical point for steady pipe flow offset by the oscillation Reynolds number.In the high frequency limit puff lifetimes are identical to those in steady pipe flow and hence the transition threshold appears toTurbulence as a Non-equilibrium Phase Transition inand below this critical probability,the average turbulence density q is 0,as the second solution is not physical.The transition is continuous,because at the critical point,the two solutions coexist at the same value,0.Above p c,there is a nonzero turbulence density solution,butTransition to turbulence in shear flows - ScienceDirectAug 15,2018 the critical point of the transition to turbulence in pipe#0183;The Reynolds number is the control parameter and the critical Reynolds number marks the transition point.The turbulent fraction f can be taken as the order parameter for the transition,and it varies for 1-d percolation like (7) f (Re Re c) 0.276.Other observables like the length and width of laminar regions scale with different

### Transition to turbulence in pulsating pipe ow

the zero limit equals to the critical point for steady pipe ow oset by the oscillation Reynolds number (i.e.the dimensionless oscillation amplitude).In the high frequency limit on the other hand pu lifetimes are identical to those in steady pipe ow and hence the transition threshold appears to be unaected by ow pulsation.Transition to turbulence in pulsating pipe flow Journal Surprisingly,even for the generic case of flow through a straight pipe,there is little consensus regarding the influence of pulsation on the transition threshold to turbulence while most studies predict a monotonically increasing threshold with pulsation frequency (i.e.Womersley number,\unicode [STIX] {x1D6FC} ),others observe a decreasing threshold for identical parameters and only observeTransition to turbulence in pulsating pipe flow : MPG.PuReThe transition point predicted in the zero alpha limit equals to the critical point for steady pipe flow offset by the oscillation Reynolds number (i.e.the dimensionless oscillation amplitude).In the high frequency limit on the other hand,puff lifetimes are identical to those in steady pipe flow and hence the transition threshold appears to

### Transition to turbulence in pulsating pipe flow - CORE

The transition point predicted in the zero limit equals to the critical point for steady pipe flow offset by the oscillation Reynolds number (i.e.the dimensionless oscillation amplitude).In the high frequency limit on the other hand,puff lifetimes are identical to those in steady pipe flow and hence the transition threshold appears to be Transition to sustained turbulence in pipe flow a second In a recent study,the critical point for sustained turbulence in a pipe was estimated to be Re ~ 2040,by balancing the times scales for turbulence growth and decay processes.This work brought into focus the spatio-temporal aspects of the transition and suggested the possibility that the transition is a second order non-equilibrium phase transition.Transition and Turbulence - Princeton UniversityWhile the transition from laminar to turbulent flow occurs at a Reynolds number of approximately 2300 in a pipe,the precise value depends on whether any small disturbances are present.If the experiment is very carefully arranged so that the pipe is very smooth and there are no disturbances to the velocity and so on,higher values of Re can be obtained with the flow still in a laminar state.

Jan 25,2018 the critical point of the transition to turbulence in pipe#0183;In accordance with Reynolds proposition,we find that at lower $Re$ (here 2020),flows eventually always resume to laminar,while for higher $Re$ (${\geqslant}2060$ ),turbulence persists.The critical point for pipe flow hence falls in the interval of $2020 the critical point of the transition to turbulence in pipelt;Re the critical point of the transition to turbulence in pipelt;2060The Onset of Turbulence in Pipe Flowthat critical velocity turbulence prevails,given the right initial conditions.The observation that this critical point can be expressed in a dimen-sionless form was the basis of one of the central conceptsinfluiddynamics:theReynoldsnumber (Re = UD/n,whereU is the mean velocity,D is the pipe diameter,and n is the kinematic viscos-ity).The Onset of Turbulence in Pipe Flow ScienceWe show that in pipes,turbulence that is transient at low Reynolds numbers becomes sustained at a distinct critical point.Through extensive experiments and computer simulations,we were able to ### The Decay of Turbulence in Pipe Flow SpringerLink However,there is no current agreement about the behaviour of turbulence for higher Re whereas some experiments indicate that turbulence becomes sustained after certain critical Reynolds number,Re C,other studies show that the turbulent state keeps its transient behaviour,ruling out any critical point.Our experiments show that these Such a drag how pipe flows become turbulent Ars TechnicaJul 07,2011 the critical point of the transition to turbulence in pipe#0183;The transition,then,is the critical point between these two.However,for pipe flows,this linearized approach shows that the perturbations decay for all Reynolds numbers,even though this doesn Such a drag how pipe flows become turbulent Ars TechnicaJul 07,2011 the critical point of the transition to turbulence in pipe#0183;The transition from laminar (smooth,predictable flow) to turbulent (chaotic,randomly fluctuating flow) is currently not well understood,although empirical information allows us to ### Some results are removed in response to a notice of local law requirement.For more information,please see here.Previous123456NextThe critical point of the transition to turbulence in pipe Sep 19,2017 the critical point of the transition to turbulence in pipe#0183;Abstract Reynolds proposed that after sufficiently long times,the flow in a pipe should settle to a steady condition below a critical Reynolds number,flows should (regardless of initial conditions) always return to laminar,while above,eddying motion should persist.As shown,even in pipes several thousand diameters long,the spatio-temporal intermittent flow patterns observed at the end Phys.Rev.Lett.124,014501 (2020) - Critical Point for Jan 09,2020 the critical point of the transition to turbulence in pipe#0183;In this Letter we show that a bifurcation cascade and fully sustained turbulence can share the phase space of a fluid flow system,resulting in the presence of competing stable attractors.We analyze the toroidal pipe flow,which undergoes subcritical transition to turbulence at low pipe curvatures (pipe-to-torus diameter ratio) and supercritical transition at high curvatures,as was ### People also askWhat is turbulence in pipes?What is turbulence in pipes?In pipes,turbulence sets in despite the linear stability of the laminar HagenPoiseuille flow.The Reynolds number ( R e ) for which turbulence first appears in a given experiment the natural transition point depends on imperfections of the set-up,or,more precisely,on the magnitude of finite amplitude perturbations.The critical point of the transition to turbulence in pipe Onset of Turbulence in Pipe Flow - Warwick Insite More than 125 years ago Osborne Reynolds launched the quantitative study of turbulent transition as he sought to understand the conditions under which fluid flowing through a pipe would be laminar or turbulent 1.Since laminar and turbulent flow have vastly different drag laws 2,this question is as important now as it was in Reynolds' day.OBSERVATION OF NONLINEAR TRAVELLING WAVES IN TURBULENTTransition to turbulence in pipe flow has posed a riddle in fluid dynamics since the pioneering experiments of Reynolds[1].Although the laminar flow is linearly stable for all flow rates,practical pipe flows become turbulent at large enough flow speeds.Turbulence arises suddenly and fully without distinct steps and without a clear critical ### Lecture 10 Turbulence Transient or Sustained? Further evidence for critical point behaviour in the transition to turbulence in a pipe was presented by a novel experiment by Peixinho and Mullin in 2006 [11].In their experimental setup (depicted in Figure 6a),a short duration perturbation was used to generate a localised pu at Re = 1900.Instability during transition to turbulence of Nov 01,2019 the critical point of the transition to turbulence in pipe#0183;Researchers have found that the transition to turbulence of constant-property fluid is delayed in a constant-curvature pipe,whereas it is promoted in a serpentine tube with alternating curvature.In supercritical pressure CO 2 flow in a serpentine tube,the buoyancy and centrifugal forces both influence the transition process,which needs to be studied thoroughly.Entropy Free Full-Text Second-Order Phase Transition In quasi-one- and two-dimensional cases alike,individual patches of turbulence have finite lifetimes and eventually decay.Early propositions that individual turbulent patches (or turbulence in small domains) become sustained at a critical point [8,9,10,11] turned out to be incorrect.Despite their often long lifetimes individual patches remain transient and eventually decay following a ### Critical velocity is defined as the point where a moving Critical velocity is defined as the point where a moving bed of particles begins to deposit on the bottom of a straight horizontal pipe during slurry-transport operations.Deposition testing of slurries containing particles with well-characterized size and density suspended in fluids with known rheological properties was performed.The test results provide information to evaluate the Critical Reynolds Number - Nuclear PowerCritical Reynolds Number.The Reynolds number is the ratio of inertial forces to viscous forces and is a convenient parameter for predicting if a flow condition will be laminar or turbulent..The critical Reynolds number is associated with the laminar-turbulent transition,in which a laminar flow becomes turbulent.This is an extraordinarily complicated process,which at present is not fully Critical Point for Bifurcation Cascades and Featureless critical point,where subcritical transition and a bifurcation cascade coexist.Filled downward-pointing triangles indicate spatially expanding turbulence,while empty triangles relamina-rization.The data from Sreenivasan and Strykowsky (Ref.[37]) are the curve they refer to as the conservative lower critical ### Critical Point for Bifurcation Cascades and Featureless Transition to turbulence is subcritical at low curvatures and qualitatively similar to the one in straight pipes [3537].For larger ,instead,transition is initiated by a supercritical Hopfbifurcation[35,3739]andallelementspointtowards a bifurcation cascade [38].The dynamics of the flow at intermediate curvatures,however,remains largely unex-Cited by 17Publish Year 2018Author Vasudevan Mukund,Bj the critical point of the transition to turbulence in pipe#246;rn HofThe critical point of the transition to turbulence in pipe The critical point for pipe flow hence lies in the interval$2020 the critical point of the transition to turbulence in pipelt;Re_c the critical point of the transition to turbulence in pipelt;2060$,which is in good agreement with the recently proposed value of$Re_c=2040$.The latter estimate was based on singleCited by 17Publish Year 2018Author Vasudevan Mukund,Bj the critical point of the transition to turbulence in pipe#246;rn HofOnset of Turbulence in Pipe Flow - Warwick InsiteMore than 125 years ago Osborne Reynolds launched the quantitative study of turbulent transition as he sought to understand the conditions under which fluid flowing through a pipe would be laminar or turbulent 1.Since laminar and turbulent flow have vastly different drag laws 2,this question is as important now as it was in Reynolds' day. ### A double-refraction method of detecting turbulence The critical point of the transition to turbulence in pipe flow Vasudevan Mukund and Bj the critical point of the transition to turbulence in pipe#246;rn Hof-Flow visualization using tobacco mosaic virus Thomas J.Goreau et al-Hysteresis Curve in Reproduction of Reynolds Color-Band Experiments Hidesada Kanda and Takayuki Yanagiya-This content was downloaded from IP address 207.46.13.88 on 06/12/2019 at 22:53A critical point for bifurcation cascades and featureless In this Letter we show that a bifurcation cascade and fully sustained turbulence can share the phase space of a fluid flow system,resulting in the presence of competing stable attractors.We analyse the toroidal pipe flow,which undergoes subcritical transition to turbulence at low pipe curvatures and supercritical transition at high A Critical Point for Turbulence ScienceTurbulence can only arise through large perturbations for which the full nonlinear equations of motion have to be studied.Direct numerical simulations of the Navier-Stokes equations provided an initial suggestion for a critical Reynolds number with the discovery of fully three-dimensional,spatially extended and persistent flow structures (5,6)coherent structuresthat were subsequently ### 12345NextThe critical point of the transition to turbulence in pipe Sep 19,2017 the critical point of the transition to turbulence in pipe#0183;Reynolds proposed that after sufficiently long times,the flow in a pipe should settle to a steady condition below a critical Reynolds number,flows should (regardless of initial conditions) always return to laminar,while above,eddying motion should persist.As shown,even in pipes several thousand diameters long,the spatio-temporal intermittent flow patterns observed at the end of the (PDF) Transition to turbulence in pulsating pipe flowSep 12,2017 the critical point of the transition to turbulence in pipe#0183;The transition point predicted in the zero$\alpha$limit equals to the critical point for steady pipe flow offset by the oscillation Reynolds number. The transition to turbulence in pulsating (PDF) Transition to turbulence in pulsating pipe flowSep 12,2017 the critical point of the transition to turbulence in pipe#0183;The transition point predicted in the zero$\alpha$limit equals to the critical point for steady pipe flow offset by the oscillation Reynolds number. The transition to turbulence in ### (PDF) The Onset of Turbulence in Pipe Flow A careful study of turbulent lifetimes of turbulence induced by application to pipe flow of such small impulsive disturbances,above the critical amplitude,leads to a turbulent pattern,referred results for this questionWhat is transition to turbulence?What is transition to turbulence?Transition to turbulence can occur over a range of Reynolds numbers,depending on many factors,including the level surface roughness,heat transfer,vibration,noise,and other disturbances.To understand why this is so,and to appreciate the role of the Reynolds number in governing the stability of the flow,Transition and Turbulence - Princeton University results for this questionWhat is transient turbulence?What is transient turbulence?We show that in pipes,turbulence that is transient at low Reynolds numbers becomes sustained at a distinct critical point.Through extensive experiments and computer simulations,we were able to identify and characterize the processes ultimately responsible for sustaining turbulence.The Onset of Turbulence in Pipe Flow Science ### results for this questionIs turbulent flow higher than laminar flow?Is turbulent flow higher than laminar flow?As a result,at a given Reynolds number,the drag of a turbulent flow is higher than the drag of a laminar flow.Also,turbulent flow is affected by surface roughness,so that increasing roughness increases the drag.Transition to turbulence can occur over a range of Reynolds numbers, depending on many factors]Transition and Turbulence - Princeton University results for this questionFeedbackThe critical point of the transition to turbulence in pipe the critical point of the transition to turbulence in pipe#0183;We find that at lower$Re$(here 2020),flows eventually always laminarize,while for higher$Re$($ the critical point of the transition to turbulence in pipegt;=2060$) turbulence persists.The critical point for pipe flow hence lies in the interval$2020 the critical point of the transition to turbulence in pipelt;Re_c the critical point of the transition to turbulence in pipelt;2060$,which is in good agreement with the recently proposed value of$Re_c=2040\$. The Onset of Turbulence in Pipe Flow Semantic ScholarThe lifetimes of injected jet puffs are used to determine the critical point at which turbulent pipe flow is sustained.Shear flows undergo a sudden transition from laminar to turbulent motion as the velocity increases,and the onset of turbulence radically changes transport efficiency and mixing properties.Even for the well-studied case of pipe flow,it has not been possible to determine at

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