力学大会2015集蝌蚪并列游动的数值研究

1,2,3，1,2,31.（交通大学工程力学系，3.（交通大学与千叶大学国际合作， 因此整个模型和厚度为0.2L。1。本文的运动波长为1，使蝌蚪以C型运动。1基金项目:国家自然科学基金项目 2.55π/s 0.875L、1L的数值模拟。图5给出了对应的平均阻力系数和相对功率系数。 力系数Cd0组成了两组交织的轨迹。负涡-V1在尾流中的运动已标注在图中，-V11则是上一个周期中同一条蝌蚪脱落的负涡，可以看到明显-V1向图6上方运动。部，尾部正在向反向运动产生与此头部涡相反的涡。在头部涡影响下，细长的尾涡成一强一弱1.25Hz1.4Hz（2.5π/s2.8π/s）下0.5L、0.625L、0.75L、0.875L、1L8为并列反向位游动的的平均阻力2.8π/s0.75时阻力系数开始为负，即此时运动使蝌蚪整体产生向前的推力，并 力系数Cd00.5L时的涡量分布（9）0.5L时，头部仍然产生了很强的头部一个运动周期形成四个涡，是由原本的一对尾涡受头部涡影响后产生的。1.275倍于来流速度时达到平衡。头部产生了一对涡，沿蝌0.75L以内，阻力系数会迅速增大，伴随着功率消耗的减少。虽然消耗1WassersugRJ,HoffK.Thekinematicsofswimminginanuranlarvae.J.exp.biol,1985,119:1-2DongG.J,LuX.Y.Characteristicsofflowovertravelingwavyfoilsinaside-by-sidearrangement.PHYSICSOFFLUIDS,2007,4LiuH,WassersugR,KawachiK.Thethree-dimensionalhydrodynamicsoftadpole 1997,200:2807-2819.1996,199:1245-1260NumericalstudyontheparallelswimmingofChen Hu(1DepartmentofEngineeringMechanics,ShanghaiJiaoTongUniversity,No.800DongchuanRoad,Shanghai200240,(2ShanghaiJiaoTongUniversityandChibaUniversityInternationalCooperativeResearchCenter,No.800DongchuanRoad,Shanghai200240,)（3MOEKeyLaboratoryofHydrodynamics,ShanghaiJiaoTongUniversity,No.800DongchuanRoad,Shanghai200240,Inthispaper,anumericalsimulationofsame-phaseandanti-phasetadpolesswimmingside-by-sideiscarriedout.Theresultiscomparedwithasingletadpolesswimming,andwiththeside-by-sideswimmingstreamlinebody.Thecharacteristicoftadpoleschoolingswimmingisrevealedbyyzingthedifferentdragcoefficientsandflowfieldsunderdifferentswimmingfrequencyanddistancethe andflowfields.Differentfromstreamlinedandobjectssuchasfish,tadpolesproducesastrongvortexaftertherearpartofhead,theheadvortexoftadpolesissignificantlyenhancedwhenthedistancebetweentadpolesdecreasing, ethemainfactorsaffectingtadpole.Andmaketheresultsignificantlydifferentfromstreamlineobject.Intheanti-phaseswimmingcondition,drag coefficientsincreases(thrustdecreases),whilepowerconsumptionreduces,whendistancebetweentadpolesdecreasesatrelativelyclosedistance.Atrelativelyfardistance,thrustandpowerconsumptionincreasewithdecreasingofdistancebetween