Improvements to the AFWL HULL Code.
Abstract
Two problems were addressed during this effort: numerical diffusion, which exists in HULL, significantly affects the calculations of nuclear air bursts a low overpressure, and some HULL calculations being performed are of phenomena that have large regions of relatively little hydrodynamic activity in them and to efficiently perform these types of calculations, modifications to HULL were needed. Modifications were made to the HULL code in an attempt to reduce numerical diffusion at low overpressure by employing a version of Flux Corrected Transport (FCT). A version of FCT was provided by the AFWL and this was implemented in HULL and tested for a simulation of a spherically symmetric explosion. The modifications to HULL were made in the AFWL two-dimensional version. The low overpressure shocks were sharpened by the FCT approach for a given cell size. The improvement is not considered to be sufficient to justify the additional cost incurred as a result of the more complex numerical differencing in this particular version of FCT. In the second area, a technique was developed for avoiding computing within certain regions of the mesh, which was also implemented in the two-dimensional version, and additional quantitative criteria were established as the basis for subsequent development of better rezone techniques.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1979
- Accession Number
- ADA100108
Entities
People
- Burton S. Chambers Iii
- John A. Hasdal
- Willard R. Thomas