论文标题

在周期盒中控制Stefan问题

Control of the Stefan problem in a periodic box

论文作者

Geshkovski, Borjan, Maity, Debayan

论文摘要

在本文中,我们考虑了表面张力的一阶段Stefan问题,该问题设置为二维带状几何形状,并具有定期边界条件相对于水平方向$ x_1 \ in \ Mathbb {t} $。我们证明,通过在任意开放和非空的子集中支持的控制,该系统在任何积极的时间内都可以在任何积极的时间内控制。我们通过线性测试和二元性进行,但很快发现线性化系统不是对称的,并且伴随通过(固定)边界之间的两个状态之间具有动态耦合。因此,以$ x_1 $的傅立叶分解为动机,我们考虑了一个一维系统的家族,并且证明可观察性结果相对于傅立叶频率参数均匀。后者的结果也很新颖,因为我们计算非零傅立叶模式的基础操作员的完整频谱。另一方面,零模式系统被视为具有有限维约束的线性热方程的可控性问题。通过使用Lebeau-Robbiano策略得出了伴随的完整可观察性,然后通过组合在\ cite {tucsnak_burgers}中引入的源术语方法的适应来显示非线性系统的局部可控性。数值实验激发了一些挑战性的开放问题,甚至超出了我们本文处理的特定环境。

In this paper we consider the one-phase Stefan problem with surface tension, set in a two-dimensional strip-like geometry, with periodic boundary conditions respect to the horizontal direction $x_1\in\mathbb{T}$. We prove that the system is locally null-controllable in any positive time, by means of a control supported within an arbitrary open and non-empty subset. We proceed by a linear test and duality, but quickly find that the linearized system is not symmetric and the adjoint has a dynamic coupling between the two states through the (fixed) boundary. Hence, motivated by a Fourier decomposition with respect to $x_1$, we consider a family of one-dimensional systems and prove observability results which are uniform with respect to the Fourier frequency parameter. The latter results are also novel, as we compute the full spectrum of the underlying operator for the non-zero Fourier modes. The zeroth mode system, on the other hand, is seen as a controllability problem for the linear heat equation with a finite-dimensional constraint. The complete observability of the adjoint is derived by using a Lebeau-Robbiano strategy, and the local controllability of the nonlinear system is then shown by combining an adaptation of the source term method introduced in \cite{tucsnak_burgers} and a Banach fixed point argument. Numerical experiments motivate several challenging open problems, foraying even beyond the specific setting we deal with herein.

扫码加入交流群

加入微信交流群

微信交流群二维码

扫码加入学术交流群,获取更多资源