Conventional coupling paradigms used nowadays to couple various physics
components in reactor analysis problems can be inconsistent in their treatment of the
nonlinear terms. This leads to usage of smaller time steps to maintain stability and
accuracy requirements thereby increasing the computational time. These inconsistencies
can be overcome using better approximations to the nonlinear operator in a time stepping
strategy to regain the lost accuracy.
This research aims at finding remedies that provide consistent coupling and time
stepping strategies with good stability properties and higher orders of accuracy.
Consistent coupling strategies, namely predictive and accelerated methods, were
introduced for several reactor transient accident problems and the performance was
analyzed for a 0-D and 1-D model. The results indicate that consistent approximations
can be made to enhance the overall accuracy in conventional codes with such simple nonintrusive
techniques.
A detailed analysis of a monoblock coupling strategy using time adaptation was also
implemented for several higher order Implicit Runge-Kutta (IRK) schemes. The
conclusion from the results indicate that adaptive time stepping provided better accuracy
and reliability in the solution fields than constant stepping methods even during
discontinuities in the transients. Also, the computational and the total memory
requirements for such schemes make them attractive alternatives to be used for
conventional coupling codes.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/5000 |
| Date | 25 April 2007 |
| Creators | Mahadevan, Vijay Subramaniam |
| Contributors | Ragusa, Jean C |
| Publisher | Texas A&M University |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Thesis, text |
| Format | 1552254 bytes, electronic, application/pdf, born digital |
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