An elastic rod model for anguilliform swimming
An elastic rod model for anguilliform swimming
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DOI：
10.1007/s00285-006-0036-8
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发表时间：
2006-11-01
影响因子：
1.9
通讯作者：
Holmes, P.
中科院分区：
文献类型：
--
作者：
McMillen, T.;Holmes, P.
我们开发了一个模型的anguilliform（鳗鱼样）游泳作为一个弹性杆驱动通过随时间变化的固有曲率和流体动力学阻力，后者提出的泰勒（在Proc Roy Proc Lond A 214：158-183，1952年）。我们采用几何精确的理论和离散化所产生的非线性偏微分演化进行数值模拟，并与以前的模型组成的刚性链接或质量链连接的弹簧，阻尼器，和规定的力发电机代表肌肉进行比较。我们表明，肌肉激活驱动的运动神经元的尖峰列车通过钙动力学产生内在的曲率对应于近正弦曲线的身体形状在均匀的杆，但被动弹性导致泰勒的假设规定的形状失败，导致时间周期运动和较低的速度比泰勒预测（在Proc Roy Proc Lond A 214：158-183，1952）。我们调查的弯曲刚度，身体的几何形状，和激活模式对游泳速度，转弯行为，和加速度稳定游泳的影响。我们发现，横向均匀激活产生稳定的直线游泳和横向差异激活水平导致稳定的转折，我们认为，锥形机构减少尾部（尾端）激活（产生均匀的内在曲率）游泳速度比均匀激活。
We develop a model for anguilliform (eel-like) swimming as an elastic rod actuated via time-dependent intrinsic curvature and subject to hydrodynamic drag forces, the latter as proposed by Taylor (in Proc Roy Proc Lond A 214:158-183, 1952). We employ a eometrically exact theory and discretize the resulting nonlinear partial differential evolution both to perform numerical simulations, and to compare with previous models consisting of chains of rigid links or masses connected by springs, dampers, and prescribed force generators representing muscles. We show that muscle activations driven by motoneuronal spike trains via calcium dynamics produce intrinsic curvatures corresponding to near-sinusoidal body shapes in longitudinally-uniform rods, but that passive elasticity causes Taylor's assumption of prescribed shape to fail, leading to time-periodic motions and lower speeds than those predicted Taylor (in Proc Roy Proc Lond A 214:158-183, 1952). We investigate the effects of bending stiffness, body geometry, and activation patterns on swimming speed, turning behavior, and acceleration to steady swimming. We show that laterally-uniform activation yields stable straight swimming and laterally differential activation levels lead to stable turns, and we argue that tapered bodies with reduced caudal (tail-end) activation (to produce uniform intrinsic curvature) swim faster than ones with uniform activation.