ASTM_D_2507_-_93_2001.pdf

Designation:D 2507 93(Reapproved 2001)Standard Terminology ofRheological Properties of Gelled Rocket Propellants1This standard is issued under the fixed designation D 2507;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 These definitions2cover the flow properties of gelledpropellants of interest to the aerospace industry.2.Terminology2.1 Definitions:apparent viscosity(of a non-Newtonian fluid)the vis-cosity of a Newtonian fluid that produces the same readingin the same apparatus under identical conditions.DiscussionAvoidance of this artificial term is recom-mended.Classification of Fluids:Class INewtonian Fluida fluid that exhibits a directproportionality between shear stress and shear rate in theregion of laminar flow.DiscussionThe shear rate is independent of the time ofapplication of shear stress.Class IINon-Newtonian Shear-Thinning Fluida fluid inwhich the shear stress is not directly proportional to the shearrate and in which the shear stress-shear rate ratio decreasesas the shear stress increases.(a)Type APlastic Fluida Class II fluid that exhibits achange in shear rate directly proportional to the change in shearstress above the yield stress.(b)Type BPseudoplastic Fluida Class II fluid thatexhibits a shear stress-shear rate ratio that is independent of theduration of application of shear stress.(c)Type CThixotropic Fluida Class II fluid thatexhibits time-dependent,reversible changes of the shear stress-shear rate ratio.DiscussionThe ratio decreases asymptotically with dura-tion of shear.Class IIINon-Newtonian Shear-Thickening Fluidafluid in which the shear stress is not directly proportional tothe shear rates,and in which the shear stress-shear rate ratioincreases as the shear stress increases.(a)Type ADilatant Fluida Class III fluid that exhibitsa shear stress-shear rate ratio that is independent of the durationof application of shear stress.(b)Type BRheopectic FluidA Class III fluid thatexhibits time-dependent,reversible changes of the shear stress-shear rate ratio.DiscussionThe ratio increases asymptotically with dura-tion of shear.emulsiona two-phase liquid system in which small dropletsof one liquid(the internal phase)are immiscible in,and aredispersed uniformly throughout,a second,continuous liquidphase(the external phase).gela liquid containing a colloidal structural network thatforms a continuous matrix and completely pervades theliquid phase.DiscussionA gel deforms elastically upon application ofshear forces less than the yield stress.At shear forces above theyield stress,the flow properties are principally determined bythe gel matrix.viscositythe ratio of shear stress to shear rate.For non-Newtonian fluids,it is preferable to report shear stress andshear rate.DiscussionIf the viscosity of such a fluid is reported,theshear rate must be specified.yield stressthe maximum shear stress that can be appliedwithout causing permanent deformation.3.Keywords3.1 terminology,Dilanant fluid;terminology,Newtonianfluid;terminology,Non-Newtonian fluid;terminology,plasticfluid;terminology,propellants;terminology,Rheopectic fluid;terminology,Thixotropic fluid;terminology,yield stress1These definitions are under the jurisdiction of ASTM Committee F07 onAerospace andAircraft and are the direct responsibility of Subcommittee F07.90 onExecutive.Current edition approved March 15,1993.Published May 1993.Originallypublished as D 2507 66 T.Last previous edition D 2507 70(1983).2These definitions are identical in substance with the JANNAF definitions,“AGlossary of Rheological Terms,”Part I of“Heterogeneous Propellant Characteriza-tion,”Liquid Propellant Test Methods,March 1967,published by the ChemicalPropulsion Information Agency,Johns Hopkins University,Applied Physics Labo-ratory,Johns Hopkins Rd.,Laurel,MD 20707.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.NOTICE:This standard has either been superceded and replaced by a new version or discontinued.Contact ASTM International(www.astm.org)for the latest information.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard.Users of this standard are expressly advised that determination of the validity of any such patent rights,and the riskof infringement of such rights,are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised,either reapproved or withdrawn.Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters.Your comments will receive careful consid