Accession Number : ADA328616

Title :   Computation of High-Speed Reacting Flows.

Descriptive Note : Interim rept. Jun 95-May 97,

Corporate Author : FLORIDA UNIV GAINESVILLE DEPT OF AEROSPACE ENGINEERING MECHANICS AND ENGINEER ING SCIENCE

Personal Author(s) : Clutter, James K.

PDF Url : ADA328616

Report Date : JUL 1997

Pagination or Media Count : 192

Abstract : A computational study has been conducted for high-speed reacting flows relevant to munition problems, including shock-induced combustion and gun muzzle blast. The theoretical model considers inviscid and viscous flows, multi-species, finite rate chemical reaction schemes, and turbulence. A range of hydrogen and oxygen reaction mechanisms are evaluated for the shock-induced combustion problem. Characteristics of the mechanisms such as the induction time, heat release, and the second explosion limit are found to impact computational accuracy. Reaction source term treatments , including logarithmic weighting and scaling modifications,are investigated and shown to enhance solution accuracy. A k-epsilon model is used to account for the turbulent transport of heat and species. The impact of turbulence on the chemical reaction source terms is estimated by an algebraic temperature fluctuation model. Gun system simulations for both a large caliber howitzer and small caliber firearms are carried out. A reduced kinetic scheme and an algebraic turbulence model are employed. By accounting for the chemical reaction aspects of the gun muzzle blast problem the current approach is found to improve the prediction of peak overpressures and is sufficient to capture the effects produced by small caliber firearm sound suppressors.

Descriptors :   *REACTION KINETICS, *COMPUTATIONAL FLUID DYNAMICS, *COMBUSTION, HEAT TRANSFER, MATHEMATICAL MODELS, SHOCK WAVES, OVERPRESSURE, TURBULENCE, TURBULENT FLOW, HYDROGEN, OXYGEN, FLOW FIELDS, TEMPERATURE GRADIENTS, SMALL ARMS, INVISCID FLOW, VISCOUS FLOW, BLAST, GUNFIRE, GUN MUZZLES, HOWITZERS.

Subject Categories : Fluid Mechanics
      Combustion and Ignition
      Guns

Distribution Statement : APPROVED FOR PUBLIC RELEASE