简介：Thebodysurfaceofsomeorganismshasnon-smoothstructure,whichisrelatedtodragreductioninmovingfluid.Toimitatethesestructures,modelswithanon-smoothsurfaceweremade.Inordertofindarelationshipbetweendragreductionandthenon-smoothsurface,anorthogonaldesigntestwasemployedinalowspeedwindtunnel.Sixfactorslikelytoinfluencedragreductionwereconsidered,andeachfactortestedatthreelevels.Thesixfactorsweretheconfiguration,diameter/bottomwidth,height/depth,distribution,thearrangementoftheroughstructuresontheexperimentalmodelandthewindspeed.Itwasshownthatthenon-smoothsurfacecausesdragreductionandthedistributionofnon-smoothstructuresonthemodel,andwindspeed,arethepredominantfactorsaffectingdragreduction.Usinganalysisofvariance,theoptimalcombinationandlevelswereobtained,whichwereawindspeedof44m/s,distributionofthenon-smoothstructureonthetailoftheexperimentalmodel,theconfigurationofriblets,diameter/bottomwidthof1mm,height/depthof0.5mm,arrangedinarhombicformation.Attheoptimalcombinationmentionedabove,the99%confidenceintervalfordragreductionwas11.13%to22.30%.