resourcewinds
winds 时间:2021-01-11 阅读:()
0,04,08,012,016,056789101112veer(°)windspeed(m/s)site1site2site3max(p95)Practicalmeasurementsofwindconditionsattallhubheightsindifferentterrain:ModellingWindConditionsforTallHubHeightsDavidHilbert(1),CarolinSchmitt(2),CatherineMeissner(3)(1)REpowerSystemsSE,Germany(2)juwiWindGmbH,Germany(3)WindSimAS,NorwayTallhubheightsreachintotheso-calledEkmanlayer,wherethecommonscalingassumptionsofthesurfacelayerarenotvalidanymore.
Withincreasingheightcoriolisforce,stabilityeffectsandmesoscaleeffectsgetmoreandmoreimportant,makingaunifieddescriptionofthewindprofileintheABLdifficult.
TothisdatenocommercialmicroscalemodellingsoftwarecontainsthefullphysicaldescriptionoftheentireABL.
Attemptstodescribethewindprofileabovethesurfacelayerrequiremeteorologicalparameterswhicharenotavailablefromstandardmastmeasurements([2],[3],[4]).
Aflowmodelwouldfurthermoreneedtomaintainthecappinginversion(Fig.
1)todescribethewholeABLsuccessfully.
Thisinvolvesassumptionswhicharehardtoverifyforpracticalcases.
Therefore,itmayalsobereasonabletoapplysurfacelayerflowmodelsandstudytheiruncertainties.
Dependingonthesitespecificconditions,anyofthoseattemptsmayleadtofalseestimatesofthewindconditionsattallhubheights.
Tallhubheightswhichreach100mandmoreposeachallengeforwindresourceassessment:Conventionalmeasurementsseldomcovertheseheightsandcommonindustryflowmodelsaretechnicallynotvalidinthoselevelsoftheatmosphericboundarylayer(ABL).
Theoryandpracticalmeasurementsshowthatflowfeaturesfortallhubheightsdifferfromthewell-knownrelationsofthesurfacelayer.
Thedemonstrationofconsequentmodellingerrorsofcommonindustryflowmodelsandsomeimmediateremediesconcludethisanalysis.
Resultsfromsixdifferentflowmodelscomparedtoremotesensingmeasurementsatasiteinsimpleterraindemonstratemodellingerrors(Fig.
8).
Inthisexamplemeasureddatafrom100mservedasareference.
Allmodelsunderestimatethewindresourceabove100mwhilstmostofthemachievegoodprofilematchesforlowerheights.
CFDresultsandanalyticalprofilesaccordingtoGryning[3]usingdifferentassumptionsfortheABLheightarecomparedtomeasurements(Fig.
9).
AgaintheCFDmodelhasdifficultiespredictingtheflowabove100m.
TheanalyticalprofilesdependontheABLheight,aparameterwhichisnotavailablefromstandardmastmeasurements.
Thus,thecorrectorincorrectassumptionoftheABLheighthasadecisiveinfluenceontheirperformance.
Highmeasurementscanserveasanimmediateremedy:InFig.
10itcanbeobservedthatmeasurementswithinthesurfacelayerdonotsufficeforareliableextrapolationtohighhubheights.
Ifconverselymeasurementsuptoorevenabovehubheightareavailable,theuncertaintyofmodelbasedverticalextrapolationfortallturbinescanbereducedsignificantly.
Furthermorehighmeasurementscanhelpinapropermodelsetup.
Fig.
11showsastandardCFDmodelwhichroughlymatchesmeasurementsbelow80m,butperformspoorlyabove.
Usingavailablehighmeasurementsthemodelsettingscanbeadjustedsotoachievesatisfyingresultsevenabove100m.
AbstractPO.
ID195ModellingErrorsTheoryRemediesMeasurementsConclusionEWEA2013,Vienna,Austria:Europe'sPremierWindEnergyEvent[1]Adaptedfromhttp://commons.
wikimedia.
org/wiki/File:Atmospheric_boundary_layer.
svg[2]Wilson,J.
D.
,Flesch,T.
K.
,2004:Anidealizedmeanwindprofilefortheatmosphericboundarylayer.
Bound.
-LayerMeteorol.
110,281-299.
[3]Gryning,S-E.
,Jrgensen,H.
,Larsen,S.
,Batchvarova,2007:Thewindprofileupto300metersoverflatterrain.
J.
Phys.
:Conf.
Ser.
75.
[4]Kelly,M.
,Gryning,S-E.
,2010:Long-TermMeanWindProfilesBasedonSimilaritytheory.
Bound.
-LayerMeteorol.
136,377-390.
TallhubheightsreachintotheEkmanlayer,wherethecommonscalingassumptionsofthesurfacelayerarenotvalidanymore.
Attemptstodescribethewindprofileaboveapprox.
100mrequiremeteorologicalparameterswhicharenotavailablefromstandardmastmeasurements.
Thus,assumptionshavetobemadewhicharehardtoverifyforpracticalcases.
Dependingonthesitespecificconditions,thesefactsmayleadto(severely)falseestimatesofthewindconditionsathubheight.
Whenusingflowmodelswhichhavebeenvalidatedwellinthesurfacelayertoestimatethewindconditionsfortallhubheights,remotesensingmeasurementsreachingheightsaboveareessentialinreducingextrapolationerrorstoacceptablelevels.
Theycanalsoaidinthemodelsetup,thusachievingabetteroverall"modelfit".
HighmeasurementsarefinallyaprerequisitefordevelopingandvalidatingnewparameterizationsforABLflow,specificallyforareasabovethesurfacelayer.
SitesinsimpleterrainSiteincomplexterrainFig.
2:Commonpowerlawfitstendtounderestimatethewindspeedatheightsabove100meter.
Fig.
3:Orographyinduceslowshear,sowindspeedathighheightsisoverestimatedwithpowerlawfit.
WindspeedWindshearWindveerFig.
6:Variationofwindveerbetweentopandlowestmeasurementheight(averageandmaxvalues).
Fig.
7:WindvectorplottedoverheightrevealsthetypicalEkmanspiralforthis10-minsample.
Fig.
8:Sixdifferentmodelresultscomparedtoremotesensingmeasurements.
Themeasureddatahasbeenfilteredforneutralatmosphericconditions.
Fig.
9:CFDmodelresultsandanalyticalprofilesaccordingto[3]fortwoestimatesoftheABLheight(h).
Themeasureddatahasbeenfilteredforneutralatmosphericconditions.
Fig.
10:Verticalextrapolationsbasedonlowermeasurementheightscomparedtoactualmeasurements.
Fig.
11:Comparisonofflowmodelsetups(standard/adaptedforhighermeasurements)Fig.
4:Measurementsshowhowthewindshearvaries–andincreases–overheight.
Fig.
5:Thesheardecreaseswithheightatthissite,andtheextentdependsstronglyonthewinddirection.
Fig.
1:ABLwithitscharacteristicdiurnalfeatures[1].
0501001502002504681012height(m)windspeed(m/s)simplesite1simplesite2simplesite3Pow.
fits0501001502002504681012height(m)windspeed(m/s)complexsitePow.
fit0501001502000,100,200,300,40height(m)shear(Hellmann-alpha)site1site2site300,10,20,30,4030609012015018021024027030033080-100m100-160m0204060801001201401601802000246810height(m)windspeed(m/s)measurementsCFDresultsGryningh=2000mGryningh=300m0501001502002500,50,70,91,11,31,5height(m)relativewindspeed(-)measurementsCFDstandardCFDadapted4060801001201401601802004,55,56,57,58,5height(m)windspeed(m/s)measurementsmodel1model2model3model4model5model6AcknowledgementsTheauthorsherebythanktheMeteorologicalInstituteattheKarlsruheInstituteofTechnologyforprovidingthemeasurementdataforFig.
9.
0501001502002505791113height(m)windspeed(m/s)simplesitebelow100msimplesiteabove100mcomplexsitebelow100mcomplexsiteabove100m
Withincreasingheightcoriolisforce,stabilityeffectsandmesoscaleeffectsgetmoreandmoreimportant,makingaunifieddescriptionofthewindprofileintheABLdifficult.
TothisdatenocommercialmicroscalemodellingsoftwarecontainsthefullphysicaldescriptionoftheentireABL.
Attemptstodescribethewindprofileabovethesurfacelayerrequiremeteorologicalparameterswhicharenotavailablefromstandardmastmeasurements([2],[3],[4]).
Aflowmodelwouldfurthermoreneedtomaintainthecappinginversion(Fig.
1)todescribethewholeABLsuccessfully.
Thisinvolvesassumptionswhicharehardtoverifyforpracticalcases.
Therefore,itmayalsobereasonabletoapplysurfacelayerflowmodelsandstudytheiruncertainties.
Dependingonthesitespecificconditions,anyofthoseattemptsmayleadtofalseestimatesofthewindconditionsattallhubheights.
Tallhubheightswhichreach100mandmoreposeachallengeforwindresourceassessment:Conventionalmeasurementsseldomcovertheseheightsandcommonindustryflowmodelsaretechnicallynotvalidinthoselevelsoftheatmosphericboundarylayer(ABL).
Theoryandpracticalmeasurementsshowthatflowfeaturesfortallhubheightsdifferfromthewell-knownrelationsofthesurfacelayer.
Thedemonstrationofconsequentmodellingerrorsofcommonindustryflowmodelsandsomeimmediateremediesconcludethisanalysis.
Resultsfromsixdifferentflowmodelscomparedtoremotesensingmeasurementsatasiteinsimpleterraindemonstratemodellingerrors(Fig.
8).
Inthisexamplemeasureddatafrom100mservedasareference.
Allmodelsunderestimatethewindresourceabove100mwhilstmostofthemachievegoodprofilematchesforlowerheights.
CFDresultsandanalyticalprofilesaccordingtoGryning[3]usingdifferentassumptionsfortheABLheightarecomparedtomeasurements(Fig.
9).
AgaintheCFDmodelhasdifficultiespredictingtheflowabove100m.
TheanalyticalprofilesdependontheABLheight,aparameterwhichisnotavailablefromstandardmastmeasurements.
Thus,thecorrectorincorrectassumptionoftheABLheighthasadecisiveinfluenceontheirperformance.
Highmeasurementscanserveasanimmediateremedy:InFig.
10itcanbeobservedthatmeasurementswithinthesurfacelayerdonotsufficeforareliableextrapolationtohighhubheights.
Ifconverselymeasurementsuptoorevenabovehubheightareavailable,theuncertaintyofmodelbasedverticalextrapolationfortallturbinescanbereducedsignificantly.
Furthermorehighmeasurementscanhelpinapropermodelsetup.
Fig.
11showsastandardCFDmodelwhichroughlymatchesmeasurementsbelow80m,butperformspoorlyabove.
Usingavailablehighmeasurementsthemodelsettingscanbeadjustedsotoachievesatisfyingresultsevenabove100m.
AbstractPO.
ID195ModellingErrorsTheoryRemediesMeasurementsConclusionEWEA2013,Vienna,Austria:Europe'sPremierWindEnergyEvent[1]Adaptedfromhttp://commons.
wikimedia.
org/wiki/File:Atmospheric_boundary_layer.
svg[2]Wilson,J.
D.
,Flesch,T.
K.
,2004:Anidealizedmeanwindprofilefortheatmosphericboundarylayer.
Bound.
-LayerMeteorol.
110,281-299.
[3]Gryning,S-E.
,Jrgensen,H.
,Larsen,S.
,Batchvarova,2007:Thewindprofileupto300metersoverflatterrain.
J.
Phys.
:Conf.
Ser.
75.
[4]Kelly,M.
,Gryning,S-E.
,2010:Long-TermMeanWindProfilesBasedonSimilaritytheory.
Bound.
-LayerMeteorol.
136,377-390.
TallhubheightsreachintotheEkmanlayer,wherethecommonscalingassumptionsofthesurfacelayerarenotvalidanymore.
Attemptstodescribethewindprofileaboveapprox.
100mrequiremeteorologicalparameterswhicharenotavailablefromstandardmastmeasurements.
Thus,assumptionshavetobemadewhicharehardtoverifyforpracticalcases.
Dependingonthesitespecificconditions,thesefactsmayleadto(severely)falseestimatesofthewindconditionsathubheight.
Whenusingflowmodelswhichhavebeenvalidatedwellinthesurfacelayertoestimatethewindconditionsfortallhubheights,remotesensingmeasurementsreachingheightsaboveareessentialinreducingextrapolationerrorstoacceptablelevels.
Theycanalsoaidinthemodelsetup,thusachievingabetteroverall"modelfit".
HighmeasurementsarefinallyaprerequisitefordevelopingandvalidatingnewparameterizationsforABLflow,specificallyforareasabovethesurfacelayer.
SitesinsimpleterrainSiteincomplexterrainFig.
2:Commonpowerlawfitstendtounderestimatethewindspeedatheightsabove100meter.
Fig.
3:Orographyinduceslowshear,sowindspeedathighheightsisoverestimatedwithpowerlawfit.
WindspeedWindshearWindveerFig.
6:Variationofwindveerbetweentopandlowestmeasurementheight(averageandmaxvalues).
Fig.
7:WindvectorplottedoverheightrevealsthetypicalEkmanspiralforthis10-minsample.
Fig.
8:Sixdifferentmodelresultscomparedtoremotesensingmeasurements.
Themeasureddatahasbeenfilteredforneutralatmosphericconditions.
Fig.
9:CFDmodelresultsandanalyticalprofilesaccordingto[3]fortwoestimatesoftheABLheight(h).
Themeasureddatahasbeenfilteredforneutralatmosphericconditions.
Fig.
10:Verticalextrapolationsbasedonlowermeasurementheightscomparedtoactualmeasurements.
Fig.
11:Comparisonofflowmodelsetups(standard/adaptedforhighermeasurements)Fig.
4:Measurementsshowhowthewindshearvaries–andincreases–overheight.
Fig.
5:Thesheardecreaseswithheightatthissite,andtheextentdependsstronglyonthewinddirection.
Fig.
1:ABLwithitscharacteristicdiurnalfeatures[1].
0501001502002504681012height(m)windspeed(m/s)simplesite1simplesite2simplesite3Pow.
fits0501001502002504681012height(m)windspeed(m/s)complexsitePow.
fit0501001502000,100,200,300,40height(m)shear(Hellmann-alpha)site1site2site300,10,20,30,4030609012015018021024027030033080-100m100-160m0204060801001201401601802000246810height(m)windspeed(m/s)measurementsCFDresultsGryningh=2000mGryningh=300m0501001502002500,50,70,91,11,31,5height(m)relativewindspeed(-)measurementsCFDstandardCFDadapted4060801001201401601802004,55,56,57,58,5height(m)windspeed(m/s)measurementsmodel1model2model3model4model5model6AcknowledgementsTheauthorsherebythanktheMeteorologicalInstituteattheKarlsruheInstituteofTechnologyforprovidingthemeasurementdataforFig.
9.
0501001502002505791113height(m)windspeed(m/s)simplesitebelow100msimplesiteabove100mcomplexsitebelow100mcomplexsiteabove100m
- resourcewinds相关文档
- lackwinds
- displayedwinds
- Maximwinds
- Authoritywinds
- 公共资源winds
- 温州市建设工程招标投标协会
ZoeCloud：香港BGP云服务器,1GB内存/20GB SSD空间/2TB流量/500Mbps/KVM,32元/月
zoecloud怎么样?zoecloud是一家国人商家，5月成立，暂时主要提供香港BGP KVM VPS，线路为AS41378，并有首发永久8折优惠：HKBGP20OFF。目前，解锁香港区 Netflix、Youtube Premium ，但不保证一直解锁，谢绝以不是原生 IP 理由退款。不保证中国大陆连接速度，建议移动中转使用，配合广州移动食用效果更佳。点击进入：zoecloud官方网站地址zo...
VPSDime7美元/月，美国达拉斯Windows VPS，2核4G/50GB SSD/2TB流量/Hyper-V虚拟化
VPSDime是2013年成立的国外VPS主机商，以大内存闻名业界，主营基于OpenVZ和KVM虚拟化的Linux套餐，大内存、10Gbps大带宽、大硬盘，有美国西雅图、达拉斯、新泽西、英国、荷兰机房可选。在上个月搞了一款达拉斯Linux系统VPS促销，详情查看：VPSDime夏季促销：美国达拉斯VPS/2G内存/2核/20gSSD/1T流量/$20/年，此次推出一款Windows VPS，依然是...
Hostigger不限流量VPS年20美元
Hostigger 主机商在前面的文章中也有介绍过几次，这个商家运营时间是有一些年份，只不过在我们圈内好像之前出现的次数不多。最近这段时间商家有提供不限流量的VPS主机，逐渐的慢慢被人认识到。在前面的介绍到他们提供的机房还是比较多的，比如土耳其、美国等。今天看到Hostigger 商家居然改动挺大的，原来蛮好的域名居然这次连带官方域名都更换掉去掉一个G（Hostiger ）。估摸着这个域名也是之前...
winds为你推荐
-
美国免费主机有没有更好的免费主机，cm域名注册cm域名是什么含义？价格是多少？注册地址是多少？有什么投资价值？info域名注册百度还收录新注册的info域名吗？免费虚拟主机申请求免费可以申请的域名和虚拟主机便宜的虚拟主机哪里有便宜的国内虚拟主机？台湾vps做一个论坛，请问需要什么样的vps配置100m网站空间50M的网页内容买100M的网站空间够用了没？什么是虚拟主机虚拟主机是什么100m虚拟主机100M的虚拟主机都能做些什么虚拟主机服务商现在市场上那家服务商的虚拟主机性价比最高？