Forward and Inverse Problems in Towed Cable Hydrodynamics
Forward and Inverse Problems in Towed Cable Hydrodynamics
复制标题
拖缆流体动力学中的正向和逆向问题
DOI：
10.1016/j.oceaneng.2008.07.001
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发表时间：
2008
影响因子：
5
通讯作者：
W. Lionheart
中科院分区：
文献类型：
--
作者：
N. Polydorides;Eskild Storteig;W. Lionheart
本文讨论了在海上地震勘探中，撞击拖缆的海流速度的重建问题。本研究考虑了一个二维模型，描述了一个灵活的，不可扩展的电缆在不可压缩流体中的水动力阻力的存在下的运动。在第一部分中，前向模型介绍，然后解决产生的拖缆的速度，曲率和张力的知识的拖船的运动和所施加的水动力载荷。在序列中，我们制定的逆问题推断的海流速度从离散样本的电缆的形状和张力，并表明这是秩亏和不适定。在接近反问题的数值稳定算法的基础上，采用广义Tikhonov正则化，在离散噪声信号的鲁棒微分的背景下。为了证明该方案的实际性能，给出了使用模拟噪声数据获得的海流重建的一些例子。
This paper addresses the problem of reconstructing the velocities of the ocean currents impinging on a towed streamer cable during an offshore seismic survey. This study considers a two-dimensional model describing the motion of a flexible, inextensible cable in the presence of hydrodynamic drag forces in an incompressible fluid. In the first part the forward model is introduced and then solved to yield the cable's velocity, curvature and tension in the knowledge of the towing vessel motion and the hydrodynamic loads applied. In sequence, we formulate the inverse problem of inferring the ocean current velocities from discrete samples of the cable's shape and tension and show that this is rank deficient and ill-posed. In approaching the inverse problem a numerically stable algorithm is adopted based on generalized Tikhonov regularization, in the context of robust differentiation of discrete noisy signals. In order to demonstrate the practical performance of the scheme, some examples of ocean current reconstructions obtained using simulated noisy data are presented.