Model Validation for High-Power Laser Ignition of JA2 Propellant

Abstract

A study of JA2 ignition using high-power (3 kW) pulsed Nd: glass lasers at low loading densities was undertaken to help construct models for predicting initial pressurization in bombs at high loading densities. Comparisons were made with results of experiments using a low-power (0.1 kW) continuous wave (cw) CO2 laser. Differences in wavelength dependence of optical properties and time dependence of the laser pulse were considered. Measured infrared (IR) emission delays agreed with the calculated "reaction" delays using a condensed-phase model. The calculations are sensitive to values used for optical properties. Experiments in which laser energy and beam diameter were varied indicate that there is an upper limit on flux density values for flamespreading to occur. Exceeding the limit leads only to ablation. An understanding of the ablation process due to high-power irradiation of energetic solids is needed to predict the pressure response of solid propellant to high-power lasers.

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Document Details

Document Type
Technical Report
Publication Date
Sep 01, 1999
Accession Number
ADA368616

Entities

People

  • A. J. Kotlar
  • A. Whren
  • Avi J. Cohen
  • Kevin L. McNesby
  • R. A. Beyer

Organizations

  • United States Army Research Laboratory

Tags

Communities of Interest

  • Energy and Power Technologies
  • Weapons Technologies

DTIC Thesaurus Topics

  • Absorption Coefficients
  • Chemical Reactions
  • Combustion
  • Energetic Materials
  • Exothermic Reactions
  • Flux Density
  • Heat Transfer
  • Ignition
  • Ignition Lag
  • Laser Beams
  • Laser Ignition Systems
  • Materials
  • Optical Properties
  • Propellants
  • Surface Temperature
  • Thermophysical Properties
  • Two Dimensional

Fields of Study

  • Physics

Readers

  • Combustion and Flow Dynamics.
  • Combustion science or combustion engineering.
  • Optical Physics and Photonics.

Technology Areas

  • Directed Energy