High Speed Flow in Tubes
Abstract
Four interior ballistic models were developed for analyzing the flow field inside tubes that launch high-speed projectile. The first model was developed for analyzing inviscid interior ballistic flow; the second was developed for analyzing the unsteady, two-dimensional momentum and thermal wall boundary layers in ballistic devices. The third model was developed for analyzing viscous interior ballistic flow; and the fourth is an analytical model that predicts the density and pressure variation between the breech and the base of the projectile. Results obtained were compared with experiment data. Results indicated that the following parameters have significant effects on the interior ballistic flow; covolume of the gas; cross-sectional areas changes as a function of axial distance; relative velocity between the propellant grains and the combustion gas; ratio of the specific heats as a function of local temperature; the effects of friction and the heat transfer in the boundary layer; and propellant burning rate as a function of local pressure. The effect of heat transfer was to produce a significant (9+%) effective barrel volume increase. The down bore pressure and density gradients were found to be governed by the projectile acceleration and the length from breech to projectile. Keywords: Interior ballistics; Gas gradients; Unsteady boundary layers; Boundary layer flow; Viscous flow; Gun barrels; Gun propellants.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 14, 1987
- Accession Number
- ADA181802
Entities
People
- Elmer Hansen
- Tom I-p. Shih
Organizations
- University of Florida