仿鱼类游动模式下的摆动翼水动力性能研究
|
摘要
以二维NACA0012水翼为计算模型,基于计算流体力学(CFD)方法,采用RNGk-ε湍流模型,利用动网格技术,数值计算了不同斯特哈尔数(St)下正弦摆动模式(SM)水翼的平均推力系数,通过与实验对比,验证了计算方法的有效性.基于鱼类身躯的柔性波动,建立了仿鱼类摆动模式(FM)水翼的动力学模型,探讨了不同侧向平移幅值下,两种模式水翼的推进性能.计算结果表明:FM水翼的平均推力始终大于SM水翼,侧向平移幅值为0.8c (c为水翼弦长)处,有最大增量7.2%.尾涡分析表明:侧向平移幅值较小时,两种模式水翼脱落涡呈反卡门涡街形式,FM水翼脱落涡强度高、耗散快;随着侧向平移幅值增大,涡系诱导作用增强,侧向射流增强.
Based on computational fluid dynamics(CFD) method,the mean thrust coefficient of the Sinusoidal oscillation mode(SM)foil with a NACA0012 shape under different Strouhal Number(St) was numerical simulated by RNG k-ε turbulent model and dynamic mesh method.The comparison with the experimental data indicated that the numerical method was applicable and effective.Based on the flexible undulation of fish body,a kinematic mode of the fish-like flapping mode(FM) foil was established.The propulsive performance of two types of foil under different lateral undulation amplitudes was discussed.The calculation results show that the average thrust of the FM foil is always greater than that of the SM foil,and the lateral undulation amplitude is 0.8 c(c is the chord length of the foil) with a maximum increase of 7.2%.Vortex wake analysis shows that when the lateral undulation amplitude is small,the wake is in the form of a reverse Karman vortex street.The FM foil's off-eddy vortex has high strength and dissipates fast.With the increase of the lateral undulation amplitude,the vortex induction effect is enhanced and the lateral jet is enhanced.
Based on computational fluid dynamics(CFD) method,the mean thrust coefficient of the Sinusoidal oscillation mode(SM)foil with a NACA0012 shape under different Strouhal Number(St) was numerical simulated by RNG k-ε turbulent model and dynamic mesh method.The comparison with the experimental data indicated that the numerical method was applicable and effective.Based on the flexible undulation of fish body,a kinematic mode of the fish-like flapping mode(FM) foil was established.The propulsive performance of two types of foil under different lateral undulation amplitudes was discussed.The calculation results show that the average thrust of the FM foil is always greater than that of the SM foil,and the lateral undulation amplitude is 0.8 c(c is the chord length of the foil) with a maximum increase of 7.2%.Vortex wake analysis shows that when the lateral undulation amplitude is small,the wake is in the form of a reverse Karman vortex street.The FM foil's off-eddy vortex has high strength and dissipates fast.With the increase of the lateral undulation amplitude,the vortex induction effect is enhanced and the lateral jet is enhanced.
引文
[1]TRIAN T M S.An efficient swimming machine[J].Scien-tific American,1995,272(3):64-70.
[2]成巍.仿生水下机器人仿真与控制技术研究[D].哈尔滨:哈尔滨工程大学船舶工程学院,2004.
[3]MASOOMI S F,GUTSCHMIDT S,CHEN X Q,et al.The kinematics and dynamics of undulatory motion of a tuna-mimetic robot[J].International Journal of Advanced Robotic Systems,2015,12(7):83.
[4]YANG L,SU Y.CFD simulation of flow features and vorticity structures in tuna-like swimming[J].China Ocean Engineering,2011,25(1):73-82.
[5]刘焕兴,苏玉民,张曦,等.尾鳍柔性变形对仿金枪机器鱼自主游动的影响[J].华中科技大学学报:自然科学版,2014,42(3):117-121.
[6]于宪钊,苏玉民,王兆立.基于RANS方程的对拍翼推进器推进性能分析[J].船舶力学,2011,15(5):449-455.
[7]张曦,苏玉民,王兆立.振动半圆柱尾流中的二维摆动水翼推进性能研究[J].船舶力学,2012,16(4):333-341.
[8]DEWAR H,GRAHAM J.Studies of tropical tuna swimming performance in a large water tunnel-kinematics[J].Journal of Experimental Biology.1994,192(1):45-59.
[9]BARRETT D S.Propulsive efficiency of a flexible hull underwater vehicle[D].Massachusetts:Department of Ocean Engineering,Massachusetts Institute of Technology,1996.
[10]FISH F E,LAUDER G V.Passive and active flow control by swimming fishes and mammals[J].Annual Review of Fluid Mechanics,2006,38:193-224.
[11]GRAHAM J B,DICKSON K A.Tuna comparative physiology.Journal of Experimental Biology,2004,207(23):4015-24.
[12]王福军.计算流体动力学分析--CFD软件原理与应用[M].北京:清华大学出版社,2004.
[13]READ D A,HOVER F S,TRIANTAFYLLOU M S.Force on oscillating foils for propulsion and maneuvering[J].Journal of Fluids and Structures,2003,17(1):163-183.
[2]成巍.仿生水下机器人仿真与控制技术研究[D].哈尔滨:哈尔滨工程大学船舶工程学院,2004.
[3]MASOOMI S F,GUTSCHMIDT S,CHEN X Q,et al.The kinematics and dynamics of undulatory motion of a tuna-mimetic robot[J].International Journal of Advanced Robotic Systems,2015,12(7):83.
[4]YANG L,SU Y.CFD simulation of flow features and vorticity structures in tuna-like swimming[J].China Ocean Engineering,2011,25(1):73-82.
[5]刘焕兴,苏玉民,张曦,等.尾鳍柔性变形对仿金枪机器鱼自主游动的影响[J].华中科技大学学报:自然科学版,2014,42(3):117-121.
[6]于宪钊,苏玉民,王兆立.基于RANS方程的对拍翼推进器推进性能分析[J].船舶力学,2011,15(5):449-455.
[7]张曦,苏玉民,王兆立.振动半圆柱尾流中的二维摆动水翼推进性能研究[J].船舶力学,2012,16(4):333-341.
[8]DEWAR H,GRAHAM J.Studies of tropical tuna swimming performance in a large water tunnel-kinematics[J].Journal of Experimental Biology.1994,192(1):45-59.
[9]BARRETT D S.Propulsive efficiency of a flexible hull underwater vehicle[D].Massachusetts:Department of Ocean Engineering,Massachusetts Institute of Technology,1996.
[10]FISH F E,LAUDER G V.Passive and active flow control by swimming fishes and mammals[J].Annual Review of Fluid Mechanics,2006,38:193-224.
[11]GRAHAM J B,DICKSON K A.Tuna comparative physiology.Journal of Experimental Biology,2004,207(23):4015-24.
[12]王福军.计算流体动力学分析--CFD软件原理与应用[M].北京:清华大学出版社,2004.
[13]READ D A,HOVER F S,TRIANTAFYLLOU M S.Force on oscillating foils for propulsion and maneuvering[J].Journal of Fluids and Structures,2003,17(1):163-183.