In this paper, we are interested to an inverse Cauchy problem governed by the Stokes equation, called the data completion problem. It consists in determining the unspecified fluid velocity, or one of its components over a part of its boundary, by introducing given measurements on its remaining part. As it's known, this problem is one of the highly ill-posed problems in the Hadamard's sense \cite{had}, it is then an interesting challenge to carry out a numerical procedure for approximating their solutions, mostly in the particular case of noisy data. To solve this problem, we propose here a regularizing approach based on a coupled complex boundary method, originally proposed in \cite{source}, for solving an inverse source problem. We show the existence of the regularization optimization problem and prove the convergence of the subsequence of optimal solutions of Tikhonov regularization formulations to the solution of the Cauchy problem. Then we suggest the numerical approximation of this problem using the adjoint gradient technic and the finite element method of $P1-bubble/P1$ type. Finally, we provide some numerical results showing the accuracy, effectiveness, and robustness of the proposed approach.
翻译:在本文中,我们感兴趣的是一个由斯托克斯方程式(称为数据完成问题)所支配的反大灰熊问题,即所谓的数据完成问题。它包括通过对余下部分进行特定测量,确定未指明的液体速度或其组成部分之一,从而确定其边界的一部分。众所周知,这个问题是哈达马德感知的高度不良问题之一,因此,执行一个数字程序以接近其解决办法,主要是在吵闹数据的特殊情况下。为了解决这个问题,我们在此建议一种基于混合复杂边界方法的正规化方法,最初在\cite{源代码}中提出,以解决反源问题。我们显示了正规化的优化问题的存在,并证明Tikhoonov正规化的配方与解决卡奥奇问题的最佳解决办法的相继关系。然后,我们用联合的梯度技术方法和$P1-bble/P1$的限定要素方法来建议这一问题的数字近。最后,我们提供了某种数字结果,显示提议的准确性、有效性和准确性。