Justification of Asymptotic Two-dimensional Model for Steady Navier-Stokes Equations for Incompressible Flow

Abstract  We study the asymptotic behavior of solutions to steady Navier-Stokes equations for incompressible flow in thin three-dimensional
deformed cylinders. We prove that a sequence of the solutions converges strongly to a solution of a corresponding two-dimensional
asymptotic model if the thickness of the cylinders converges to zero.

• Content Type Journal Article
• DOI 10.1007/s10440-009-9551-0
• Authors
  
  
  • Rostislav Vodák, Palacky University Department of Mathematical Analysis and Applications of Mathematics, Faculty of Science tř. 17. listopadu 1192/12 771 46 Olomouc Czech Republic
  
  

• Journal Acta Applicandae Mathematicae: An International Survey Journal on Applying Mathematics and Mathematical Applications
• Online ISSN 1572-9036
• Print ISSN 0167-8019

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Original source : http://www.springerlink.com/content/rp0332107mhh24...

Pseudospectral time-domain method for pressure-release rough surface scattering using a surface transformation and image method

Abstract  When numerically analyzing acoustic scattering at a pressure-release rough surface, the conventional pseudospectral time domain
(PSTD) method using Fourier transform requires rigorous stability conditions in order to solve the spatial derivative in the
wave equation on the irregular boundaries between the two media due to the Gibbs phenomenon and short wavelength in air. To
eliminate such disadvantages, a new algorithm is proposed based on the Fourier PSTD method utilizing a surface boundary transformation
and an image method. Irregular surface boundaries are flattened by transformation and then an image method is applied to the
half-space domain. The efficiency and accuracy of the proposed PSTD method are better than the conventional Fourier PSTD method.
Numerical results are presented for a sloped and a sinusoidal pressure-release surface.

• Content Type Journal Article
• Category Original Paper
• DOI 10.1007/s11075-009-9343-7
• Authors
  
  
  • Yonghoon Ha, Seoul National University Department of Naval Architecture and Ocean Engineering Seoul 151–744 South Korea
  • Keunwha Lee, Seoul National University Department of Naval Architecture and Ocean Engineering Seoul 151–744 South Korea
  • Woojae Seong, Seoul National University Department of Naval Architecture and Ocean Engineering Seoul 151–744 South Korea
  
  

• Journal Numerical Algorithms
• Online ISSN 1572-9265
• Print ISSN 1017-1398

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Original source : http://www.springerlink.com/content/818q5574181723...