A Radiation Diffusion and Hydrodynamics Code for Low-Altitude Multiple Bursts
Abstract
This paper describes a computer code for studying strongly interacting multiple air bursts at low altitude. It is designed to study both early and late phases of two (or more) non-simultaneous bursts at different positions along a vertical line. The code -- a two-dimensional modification of the one-fluid, implicit, Eulerian hydrodynamic code MICE -- treats radiative energy transfer in the approximation of radiation diffusion (or local thermodynamic equilibrium). This modification also treats in a rudimentary way the loss of thermal radiation from fireballs: this is calculated by using Planck mean opacities for one frequency interval to integrate the optical depth from each cell to infinity in several directions. These treatments complement one another in the sense that the radiation diffusion transfers radiant energy during a time step from each cell to the immediately adjacent cells, while the radiation loss term transfers radiant energy from each cell to infinity. The difference equations involve (further) use of the technique of time-step splitting and are implicit. The relations used for the equations of state and the Rosseland and Planck mean opacities of air are plotted, and the method for initial X-ray deposition is described. To get satisfactory results, the radiation loss rate has been artificially increased to force the correct total radiation loss.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 15, 1975
- Accession Number
- ADA015667
Entities
People
- Robert E. Stoeckly