Aerodynamic Characteristics,Power Requirements and Camber Effects of the Pitching-Down Flapping Hovering

在线阅读 下载PDF 导出详情
摘要 Thepitching-downflappingisanewtypeofbionicflapping,whichwasinventedbytheauthorbasedonpreviousstudiesontheaerodynamicmechanismsoffruitfly(pitching-up)flapping.ThemotivationofthisinventionistoimprovetheaerodynamiccharacteristicsofflappingMicroAirVehicles(MAVs).Inthispaperthepitching-downflappingisbrieflyintroduced.Themajorworksinclude:(1)Computingthepowerrequirementsofpitching-downflappinginthreemodes(advanced,symmetrical,delayed),whichwerecomparedwiththoseofpitching-upflapping;(2)Investigatingtheeffectsoftranslationalaccelerationtime,Δτ_t,androtationaltime,Δτ_r,attheendofastroke,andtheangleofattack,α,inthemiddleofastrokeontheaerodynamiccharacteristicsinsymmetricalmode;(3)Investigatingtheeffectofcamberonpitching-downflapping.Fromtheaboveworks,conclusionscanbedrawnthat:(1)Comparedwiththepitching-upflapping,thepitching-downflappingcangreatlyreducethetime-averagedpowerrequirements;(2)TheincreaseinΔτtandthedecreaseinΔτ_rcanincreaseboththeliftanddragcoefficients,butthetime-averagedratiooflifttodragchangesalittle.Andαhassignificanteffectontheaerodynamiccharacteristicsofthepitching-downflapping;(3)Thepositivecambercaneffectivelyincreasetheliftcoefficientandtheratiooflifttodrag.
作者
机构地区 不详
出版日期 2009年02月12日(中国期刊网平台首次上网日期,不代表论文的发表时间)
  • 相关文献