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1、........2010 CopyingBirdsMaySaveAircraftFuel BothBoeingandAirbushavetrumpetedtheefficiencyoftheirnewestaircraft.The787and350respectively.Theircleverdesignsandlightweightcompositescertainlymakeadifference.ButagroupofresearchersatStanfordUniversity,ledbyIlanKroo,hassuggested
2、thatairlinescouldtakeamorenaturalisticapproachtocuttingjet-fueluseanditwouldnotrequirethemtobuynewaircraft. Theanswer,saysDrKroo,lieswithbirds.Since1914,scientistshaveknownthatbirdsflyinginformation-aV-shape-expendlessenergy.Theairflowingoverabird’swingscurlsupwardsbehindth
3、ewingtips.aphenomenonknownasupwash.Otherbirdsflyingintheupwashexperiencereduceddrag,andspendlessenergypropellingthemselves.PeterLissaman,anaeronauticsexpertwhowasformerlyatCaltechandtheUniversityofSouthernCalifornia,hassuggestedthataformationof25birdsmightenjoyarangeincrease
4、of71%. Whenappliedtoaircraft,theprinciplesarenotsubstantiallydifferent.DrKrooandhisteammodeledwhatwouldhappenifthreepassengerjetsdepartingfromLosAngeles,SanFranciscoandIasVegasweretoassembleoverUtah,assumeaninvertedV-formationoccasionallychangeplacessoallcouldhaveaturninthe
5、mostfavourablepositions,andproceedtoLondon.Theyfoundthattheaircraftconsumedasmuchas15%lessfuel(coupledwithareductionincarbon-dioxideoutput).Nitrogen-oxideemissionsduringthecruisingportionsoftheflightfellbyaroundaquarter..专业学习资料......... Thereare,ofcourse,knotstobeworkedout.
6、Oneconsiderationissafety,oratleasttheperceptionofit.Wouldpassengersfeelcomfortabletravellingincompanion?DrKroopointsoutthattheaircraftcouldbeseparatedbyseveralnauticalmiles,andwouldnotbeintheintimategroupingsfavouredbydisplayteamsliketheRedArrows,Apassengerpeeringoutofthewin
7、dowmightnotevenseetheotherplanes.Whethertheseparationdistancesinvolvedwouldsatisfyair-traffic-controlregulationsisanothermatter,althoughaworkinggroupattheInternationalCivilAviationOrganisationhasincludedthepossibilityofformationflyinginablueprintfornewoperationalguidelines.
8、 Itremainstobeseenhowweatherconditionsaffecttheairflowsthatmakeformationfli
