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三维薄区域上MHD方程的渐进分析

余用江; 李开泰   

  1. 上海交通大学数学系 上海 200240
  • 收稿日期:2005-03-07 修回日期:2006-03-30 出版日期:2007-08-25 发布日期:2007-08-25
  • 通讯作者: 余用江
  • 基金资助:
    基金项目:上海交通大学数学人满天下系友基金资助

Asymptotic Analysis for MHD Equations on Thin Domains

Yu Yongjiang; Li Kaitai   

  1. Department of Mathematics, Shanghai Jiaotong University, Shanghai 200240
  • Received:2005-03-07 Revised:2006-03-30 Online:2007-08-25 Published:2007-08-25
  • Contact: Yu Yongjiang

摘要:

在强解全局存在的基础上, 得到了三维薄区域上MHD方程的解(u,h)对任意时间t≥ 0的渐进分析. 当区域厚度ε小时, MHD方程的强解(u,h)可形式展开为
u=ū(t)+up+U, h=h(t)+hp+H, t ≥0


u=ū(t)+us+U*,
h=h(t)+hs+H*,t ≥0,
其中(u,h) 是2D-3C MHD 方程的解, (u_p,h_p) 是P-S MHD 方程的解, u,h 分别是两个Stokes方程的解, (U,H),(U*,H*)是仅依赖于初始数据的两个函数对.
(U,H)和(U*,H*)关于区域厚度\varepsilon是小的, (u_p,h_p)和u,h更小;
证明了上述形式展开的收敛性.

关键词: MHD 方程, 薄区域, 渐进分析

Abstract: Based on the global existence of strong solution of MHD equations on three dimensional thin domain, asymptotic expansion for the strong solution (u,h) of
MHD equations is obtained, and this expansion holds uniformly for
all the time t≥0. When ε, the thickness of the
domain, is small, the strong solution (u,h) of MHD equations can
be formally expressed as
u=\bar{u}(t)+u_p+U,\quad
h=\bar{h}(t)+h_p+H,\quad \forall t≥0,

or
u=\bar{u}(t)+u_s+U^{\star},\quad
h=\bar{h}(t)+h_s+H^{\star},\quad \forall t≥0,
where (\bar{u},\bar{h}) is a solution of 2D-3C MHD equations, (u_{p},h_p) is a solution of P-S MHD equations, u_s,h_s are respectively solutions of two Stokes equations, (U,H),(U^\star,H^\star)
are two function pairs depending only on the initial data. (U,H) and (U^\star,H^\star)
are small with respect to
\varepsilon. (u_{p},h_p) and u_{s},h_s are smaller. And the convergence of the expansion is proved.

Key words: MHD equations, Thin domains, Asymptotic analysis

中图分类号: 

  • 35Q35