You are here:
  • Home
  • »
  • Products
  • »
  • Polymer drag reduction with surface roughness in flat

Polymer drag reduction with surface roughness in flat

Steel machining - Customized shape and size →Click on

Ordinary Steel structure OEM&ODM →Click on

Pressure vessel/large tank processing →Click on

Other steel structure processing →Click on

  • Product Description

Sustained drag reduction in a turbulent flow using a low

Here,we use the unheated superhydrophobic rotor because the very small surface roughness leads to negligible drag reduction with respect to a smooth rotor.For this system,we find M = 3.8 Polymer drag reduction with surface roughness in flat#177; 0.1 and N = 12.5 Polymer drag reduction with surface roughness in flat#177; 0.1.The presence of a local slip boundary condition on a heated superhydrophobic surface gives rise to the final term in Eq.2.Sustained drag reduction in a turbulent flow using a low Here,we use the unheated superhydrophobic rotor because the very small surface roughness leads to negligible drag reduction with respect to a smooth rotor.For this system,we find M = 3.8 Polymer drag reduction with surface roughness in flat#177; 0.1 and N = 12.5 Polymer drag reduction with surface roughness in flat#177; 0.1.The presence of a local slip boundary condition on a heated superhydrophobic surface gives rise to the final term in Eq.2.Surface Friction of Hydrogels with Well-Defined Jul 01,2004 Polymer drag reduction with surface roughness in flat#0183;With an increase in the length of the polymer brush,this drag reduction effect only works at a low sliding velocity,and the gel with long polymer brushes even shows a higher friction than that of a normal network gel at a high sliding velocity. Friction of hydrogels with controlled surface roughness on solid flat substrates.Soft Matter

Surface Friction of Hydrogels with Well-Defined

Jul 01,2004 Polymer drag reduction with surface roughness in flat#0183;With an increase in the length of the polymer brush,this drag reduction effect only works at a low sliding velocity,and the gel with long polymer brushes even shows a higher friction than that of a normal network gel at a high sliding velocity. Friction of hydrogels with controlled surface roughness on solid flat substrates.Soft Matter Some results are removed in response to a notice of local law requirement.For more information,please see here.Previous123456NextDiffusion of drag-reducing polymer solutions within a The influence of surface roughness on diffusion of wall-injected,drag-reducing polymer solutions within a turbulent boundary layer was studied with a 0.94 m long flat-plate test model at speeds of up to 10.6 m s1 and Reynolds numbers of up to 9 Polymer drag reduction with surface roughness in flat#215;106.The surface was hydraulically smooth,transitionally rough,or fully rough.Mean concentration profiles were acquired with planar laser Some results are removed in response to a notice of local law requirement.For more information,please see here.12345NextDiffusion of drag-reducing polymer solutions within a The influence of surface roughness on diffusion of wall-injected,drag-reducing polymer solutions within a turbulent boundary layer was studied with a 0.94 m long flat-plate test model at speeds of up to 10.6 m s -1 and Reynolds numbers of up to 9 Polymer drag reduction with surface roughness in flat#215;10 6 .The surface was

Some results are removed in response to a notice of local law requirement.For more information,please see here.Simulating the full-scale sea trials in the towing tanks

Petrie,H L,Deutsch,S,Brungart,T A and Fontaine,A A 2003 Polymer drag reduction with surface roughness in flat-plate turbulent boundary layer flow.Exp.Fluids 35 3-23Shark-skin surfaces for fluid-drag reduction in turbulent Oct 28,2010 Polymer drag reduction with surface roughness in flat#0183;Drag-reduction data for sawtooth riblets on a flat plate are shown in figure 12a,and drag-reduction data for water flow in sawtooth-riblet-lined pipes are shown in figure 12b.As riblets are applied to the inside surface of a pipe,the riblet tips are shifted together owing to the curve of

Shark-skin surfaces for fluid-drag reduction in turbulent

Oct 28,2010 Polymer drag reduction with surface roughness in flat#0183;Drag-reduction data for sawtooth riblets on a flat plate are shown in figure 12a,and drag-reduction data for water flow in sawtooth-riblet-lined pipes are shown in figure 12b.As riblets are applied to the inside surface of a pipe,the riblet tips are shifted together owing to the curve ofRowing faster by surface treatment - ScienceDirectJan 01,2012 Polymer drag reduction with surface roughness in flat#0183;Results 4.1.Facility validation by riblet drag measurements.Many experimental studies [9] show a maximum of 5% drag reduction for a flow over a surface with riblets that have a triangular cross-section.In order to confirm the magnitude of drag reduction in the Taylor-Couette facility,riblet foil was attached on the inner cylinder surface.Roles of drag reducing polymers in single- and multi-phase Nov 01,2014 Polymer drag reduction with surface roughness in flat#0183;The results showed that even with fully rough surfaces,there was drag reduction of over 60% for both the injected and homogeneous polymer cases.The increase in surface roughness caused the drag reduction to decrease for both cases though the decrease was quicker in

Recent Developments and Practical Feasibility of Polymer

Additionally,the best drag reduction and antifouling performance of these biomimetic shark skin surfaces are only obtained when operated in dynamic environments.Pilot Whale.The skin of pilot whales exhibits a flat,smooth surface,characterized by a pattern of nanoridgeenclosed pores,with an average pore size of 0.20 Polymer drag reduction with surface roughness in flat#181;m 2.Preparation,anti-biofouling and drag-reduction properties Drag reduction performance of the biomimetic shark skin surfaces.Torque-rotational speed curve was obtained by testing the drag reduction performances of F-PU membrane material which had smooth surface and S-PU membrane material which had surface micro-structure atPreparation,anti-biofouling and drag-reduction properties Drag reduction performance of the biomimetic shark skin surfaces.Torque-rotational speed curve was obtained by testing the drag reduction performances of F-PU membrane material which had smooth surface and S-PU membrane material which had surface micro-structure at

Polymer drag reduction with surface roughness in flat

Jun 03,2003 Polymer drag reduction with surface roughness in flat#0183;With polymer injection,increasing surface roughness caused the drag reduction to decrease to low levels more quickly when the polymer expenditure was decreased or the freestream velocity was increased.However,the percent drag reductions on the rough surfaces with polymer injection were often substantially larger than on the smooth surface.Polymer and surface roughness effects on the drag crisis Low concentration polymer solutions and/or a pattern of grooves in the sphere surface induce an early drag crisis,which may reduce drag by more than 50 percent compared to smooth spheres in pure water.On the other hand,random surface roughness and/or high concentration polymer solutions reduce drag progressively and suppress the drag crisis.Polymer and surface roughness eects on the dragOn the other hand,random surface roughness and/or high concentration polymer solutions reduce drag progressively and suppress the drag crisis.We also present a qualititative argument which ties the drag reduction observed in low concentration polymer solutions to the Weissenberg number and normal stress dierence.

Polymer and surface roughness eects on the drag

On the other hand,random surface roughness and/or high concentration polymer solutions reduce drag progressively and suppress the drag crisis.We also present a qualititative argument which ties the drag reduction observed in low concentration polymer solutions to the Weissenberg number and normal stress dierence.Parameters of Drag Reducing Polymers and Drag Reduction The drag reduction increased with polymer concentration up to 10 ppm,above which it reached a plateau value.While the drag reduction at the plateau value increases with polymer molecular weight,the maximum drag reduction was not affected by the increase in polymer charge density up to 13%.Modification of turbulent boundary layer coherent Measurements were acquired in polymer oceans (uniform concentration) at drag reduction levels corresponding to the low drag reduction regime ( Polymer drag reduction with surface roughness in flatlt;40%) and the high drag reduction (HDR) regime ( Polymer drag reduction with surface roughness in flatgt;40%) and at an intermediate level (46%).The mean velocity profiles and two-point correlations were compared with those of water (Newtonian,DR = 0%).

Investigation on Effect of Surface Roughness Pattern to

Sep 16,2005 Polymer drag reduction with surface roughness in flat#0183;A drag force reduction experiment is performed on polyoxyethylene (PEO) water solution using a rotary rheometer.Longitudinal,transverse,and isotropic grooves are notched on the rotors surface to investigate the effect of surface roughness patterns.Influence of textural statistics on drag reduction by We investigate the inuence of statistical measures of surface roughness on the turbulent drag reduction (DR) performance of four scalable,randomly rough superhydrophobic (SH) textures.Each surface was fabricated using readily scalable surface texturing processes to generate a random,self-afne height prole on the base substrate.Erratum Polymer drag reduction with surface roughness in Apr 01,2004 Polymer drag reduction with surface roughness in flat#0183;T2 - Polymer drag reduction with surface roughness in flat-plate turbulent boundary layer flow (Experiments in Fluids (2003) 35 (8-23)) AU - Petrie,H.L.AU - Deutsch,S.

Drag Reduction by Injection -

drag reduction were remarkably similar to that observed with polymer injection.Merkle and Deutsch (1989) provide a comprehensive review of early attempts at skin friction reduction by microbubble injection.Recently,Petrie et al.(2003) investigated heterogeneous polymer drag reduction over surface roughness.Drag Reduction Performance of Mechanically DegradedMechanical degradation of dilute solutions of polyethylene oxide (PEO) via chain scission was investigated within a turbulent pipe flow.Comparisons of the drag reduction performaDoD FY 2009 Budget Estimates February 2008based friction drag reduction on Navy surface ships.To date,the program has developed the capability to predict how turbulent flows are modified by the presence of polymers and air injection and has identified hull designs on which air layer drag reduction would be cost-effective.

Diffusion of drag-reducing polymer solutions within a

The influence of surface roughness on diffusion of wall-injected,drag-reducing polymer solutions within a turbulent boundary layer was studied with a 0.94 m long flat-plate test model at speeds of up to 10.6 m s1 and Reynolds numbers of up to 9 Polymer drag reduction with surface roughness in flat#215;106.The surface was hydraulically smooth,transitionally rough,or fully rough.Mean concentration profiles were acquired with planar laser Cited by 56Publish Year 2003Author H.L.Petrie,S.Deutsch,Timothy A.Brungart,Arnold Anthony FontaineFlow-induced degradation of drag-reducing polymer Feb 22,2011 Polymer drag reduction with surface roughness in flat#0183;Polymer drag reduction,diffusion and degradation in a high-Reynolds-number turbulent boundary layer (TBL) flow were investigated.The TBL developed on a flat plate at free-stream speeds up to 20ms 1.Measurements were acquired up to 10.7m downstream of the leading edge,yielding downstream-distance-based Reynolds numbers up to 220 million.Cited by 56Publish Year 2003Author H.L.Petrie,S.Deutsch,Timothy A.Brungart,Arnold Anthony Fontaine(PDF) Polymer drag reduction with surface roughness in With polymer injection,increasing surface roughness caused the drag reduction to decrease to low levels more quickly when the polymer expenditure was decreased or the freestream velocity was

Cited by 34Publish Year 2010Author Shu-Qing Yang,G.DouDiffusion of drag-reducing polymer solutions within a

The influence of surface roughness on diffusion of wall-injected,drag-reducing polymer solutions within a turbulent boundary layer was studied with a 0.94 m long flat-plate test model at speeds of up to 10.6 m s -1 and Reynolds numbers of up to 9 Polymer drag reduction with surface roughness in flat#215;10 6.The surface was hydraulically smooth,transitionally rough,or fully rough.Cited by 25Publish Year 2011Author Brian R.Elbing,Michael J.Solomon,Marc Perlin,David R.Dowling,Steven L.CeccioTurbulent drag reduction with polymer additive in rough Dec 11,2009 Polymer drag reduction with surface roughness in flat#0183;The investigation shows that the effect of polymer also changes the velocity at the top of roughness elements.Both experimental data and theoretical predictions indicate that,if same polymer solution is used,the drag reduction (DR) in roughened pipes becomes smaller relative to smooth pipe flows at the same Reynolds number.Chapter 02 Surface Roughness Analysis andcharacterization of surface roughness that are important in contact problems.Emphasis is placed on random,isotropic surfaces that follow Gaussian distribution.2.2.1 Average Roughness Parameters 2.2.1.1 Amplitude Parameters Surface roughness most commonly refers to the variations in the height of the surface relative to a reference plane.

Can dimpled aerodynamic surfaces reduce drag? - Racecar

The trade-off with this is that we are creating a slightly higher skin friction drag on the rim, continues the man from Zipp,but since this is some 10 times lower than the pressure drag,we find a bulged rim to be remarkably analogous to a golf ball in that the pressure drag reduction is many times greater than the total skin friction drag.Analysis of Drag Reduction Methods and Mechanisms ofAbstractIntroductionBionic Drag Reduction TechnologyOther Drag Reaction MethodsSummary and OutlookAcknowledgmentsTurbulent flow is a difficult issue in fluid dynamics,the rules of which have not been totally revealed up to now.Fluid in turbulent state will result in a greater frictional force,which must consume great energy.Therefore,it is not only an important influence in saving energy and improving energy utilization rate but also an extensive application prospect in many fields,such as ship domain and aerospace.Firstly,bionic drag reduction technology is reviewed and is a hot research issue now,the drag reduction mechanismSee more on hindawiShip Drag Reduction by Microalgal Biopolymers A Experimental results from a study of surface roughness effects on polymer drag reduction in a zero-pressure gradient flat-plate turbulent boundary layer are presented.Both slot-injected polymer An experimental investigation of the effect of drag A sound detector in the surface of a moving body receives not only sound signals radiated from a distant source but also detects pressure fluctuations originating in the turbulent boundary layer of the fluid surrounding the body.The purpose of the present work was to assess the magnitude of the surface pressure fluctuations on a body moving in water and in water with polymer additive under

A Review of Drag Reduction in a Turbulent Flow using Polymers

Hence these results offers an explanation of possible mechanism of polymer induced drag reduction in the outer region of wall turbulence and also in the buffer region.Petrie et al.[9] performed experimental study on the efect of surface roughness on polymer drag reduction in a flat plat turbulent boundary layer at zero pressure gradient.1.IntroductionThe strip transition on the groove surface is more flat compared with the smooth surface. in flow boiling of polymer additives Chemical Engineering 2001 29 5 22 25 32 Petrie H.L.Deutsch S.Brungart T.A.Fontain A.A.Polymer drag reduction with surface roughness in flat-plate turbulent boundary layer flow Experiments in Fluids 2003 35 1

Leave a Message

24 Hour steel Machining Response - Contact Now