1、Designation:D564095(Reapproved 2014)Standard Guide forSelection of Weirs and Flumes for Open-Channel FlowMeasurement of Water1This standard is issued under the fixed designation D5640;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,t
2、he year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This guide covers recommendations for the selection ofweirs and flumes for the measurement of the volumetric flo
3、wrate of water and wastewater in open channels under a varietyof field conditions.1.2 This guide emphasizes the weirs and flumes for whichASTM standards are available,namely,thin-plate weirs,broad-crested weirs,Parshall flumes,and Palmer-Bowlus(and otherlong-throated)flumes.However,reference is also
4、 made toother measurement devices and methods that may be useful inspecific situations.1.3 The values stated in inch-pound units are to be regardedas standard.The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard
5、.1.4 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Docu
6、ments2.1 ASTM Standards:2D1129 Terminology Relating to WaterD1941 Test Method for Open Channel Flow Measurementof Water with the Parshall FlumeD3858 Test Method for Open-Channel Flow Measurementof Water by Velocity-Area MethodD5242 Test Method for Open-Channel Flow Measurementof Water with Thin-Plat
7、e WeirsD5389 Test Method for Open-Channel Flow Measurementby Acoustic Velocity Meter SystemsD5390 Test Method for Open-Channel Flow Measurementof Water with Palmer-Bowlus FlumesD5614 Test Method for Open Channel Flow Measurementof Water with Broad-Crested Weirs2.2 ISO Standard:3ISO555-1973:LiquidFlo
8、wMeasurementinOpenChannelsDilution Methods for Measurement of SteadyFlowConstant-Rate Injection Method3.Terminology3.1 DefinitionsFor definitions of terms used in this guide,refer to Terminology D1129.3.2 Definitions of Terms Specific to This Standard:3.2.1 blackwateran increase in the depth of flow
9、 upstreamof a channel obstruction,in this case a weir or flume.3.2.2 contracted weirscontractions of thin-plate weirs re-fer to the widths of weir plate between the notch and thesidewalls of the approach channel.In fully contracted weirs,the ratio of the notch area to the cross-sectional area of the
10、approach channel is small enough for the shape of the channelto have little effect.In suppressed(full-width)rectangularweirs,the contractions are suppressed,and the weir crestextends the full width of the channel.3.2.3 crestin rectangular thin-plate weirs,the horizontalbottom of the overflow section
11、;in broad-crested weirs andflumes,the plane,level floor of the flow section.3.2.4 critical flowopen-channel flow in which the energy,expressed in terms of depth plus velocity head,is a minimumfor a given flow rate and channel.3.2.4.1 DiscussionThe Froude number is unity at criticalflow.3.2.5 Froude
12、numbera dimensionless number expressingthe ratio of inertial to gravity forces in free-surface flow.It isequal to the average velocity divided by the square root of theproduct of the average depth and the acceleration due togravity.3.2.6 headin this context,the depth of flow referenced tothe crest o
13、f the weir or flume and measured at a specified1This guide is under the jurisdiction of ASTM Committee D19 on Water and isthe direct responsibility of Subcommittee D19.07 on Sediments,Geomorphology,and Open-Channel Flow.Current edition approved Jan.1,2014.Published March 2014.Originallyapproved in 1
14、995.Last previous edition approved in 2008 as D5640 95(2008).DOI:10.1520/D5640-95R14.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page
15、onthe ASTM website.3Available from American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036,http:/www.ansi.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 location;this depth plus the velocity head are oft
16、en termed thetotal head or total energy head.3.2.7 hydraulic jumpan abrupt transition from supercriti-cal to subcritical or tranquil flow,accompanied by considerableturbulence or gravity waves,or both.3.2.8 long-throated flumea flume in which the prismaticthroat is long enough,relative to the head,for a region ofessentially critical flow to develop on the crest.3.2.9 nappethe curved sheet or jet of water overfalling aweir.3.2.10 notchthe overflow section of a triangular weir or ofa rectangular w