DIRTRAN-I User's Manual.
Abstract
The DIRTRAN-I Code is a computer-implemented model for predicting the optical effects of an explosion-produced dust cloud as it disperses in the lower atmosphere. This model is based on first principles of fluid dynamics, atmospherics, and optics. The model has been validated using cloud dimension and line-of-sight optical transmission data from the DIRT I and Graf II Winter Army dust obscuration field trials. The DIRTRAN-I Code exploits information available about crater sizes produced by explosions in conjunction with distinct models for coupling of energy to the ground for artillery projectiles versus bare charges. The model recognizes that dust ejecta are partitioned into a buoyantly rising fireball and a non-buoyant 'dust skirt' which is subject to diffusion in the vertically sheared wind field. The DIRTRAN-I Code solves separately for these two clouds. The solutions are based on atmospheric diffusion theory and take into account the effects of wind and temperature profiles in the constant shear stress layer of the lower atmosphere for different atmospheric stability categories. Separate treatment is given to particles of different sizes, the larger ones being allowed to settle out. Outputs of the code include dust cloud displacement and dimensions for both the non-buoyant wind-dominated skirt and the initial buoyant fireball as it is wind blown and eventually also becomes subject to wind diffusion.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1980
- Accession Number
- ADA081795
Entities
People
- David Dvore
Organizations
- Aerodyne Research