Implementation of a Nonlinear Filter with a Lagrangian Formulation for the Treatment of Very High Pressure Reflected Shocks

✍ Scribed by C.K.B. Lee; J.M. McDonough

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 493 KB
• Volume: 117
• Category: Article
• ISSN: 0021-9991
• DOI: 10.1006/jcph.1995.1067

✦ Synopsis

The Engquist filter is implemented within the one-dimensional Lagrangian gas dynamics code HAROLD. The conservation version and the total variation diminishing version of the filter are combined as proposed in the original paper, with filtering performed in characteristics space. The present results show that the filter performs well in the Lagrangian system for very strong shocks. A new treatment of the wall boundary reflection for strong shocks that takes advantage of the filter is presented. Reflected shocks calculated using this technique show essentially no overshoots typical of classical finitedifference codes. These results show promise in applying the filter and the characteristics scheme to more complicated gas dynamics problems not only because of the high quality of the solutions, but also because the additional run time incurred due to the filter is minimal. Furthermore, it follows that older codes formulated using second-order finite difference methods utilizing artificial viscosity can be converted into accurate, modern tools with a high potential for parallelizability. 1995 Academic Press, Inc.