NON-STEADY BURNING PHENOMENA OF SOLID PROPELLANTS: THEORY AND EXPERIMENT.

Abstract

Non-steady burning of solid propellants was investigated both theoretically and experimentally, with attention to combustion instability, transient burning during motor ignition, and extinction by depressurization. The theory is based on a one-dimensional model of the combustion zone consisting of a thin gaseous flame and a solid heat up zone. The non-steady gaseous flame behavior is deduced from experimental steady burning characteristics; the response of the solid phase is described by the time-dependent Fourier equation. Solutions were obtained for dynamic burning rate, flame temperature, and burnt gas entropy under different pressure variations; two methods were employed. First, the equations were linearized and solved by standard techniques. Then, to observe nonlinear effects, solutions were obtained by digital computer for prescribed pressure variations. One significant result is that a propellant with a large heat evolution at the surface is intrinsically unstable under dynamic conditions even though a steady-state solution exists. Another interesting result is that the gas entropy amplitude and phase depend critically on the frequency of pressure oscillation and that either near-isentropic or near-isothermal oscillations may be observable. Experiments with an oscillating combustion chamber and with a special combustor equipped for sudden pressurization tend to support the latter conclusion. (Author)

Document Details

Document Type
Technical Report
Publication Date
Jul 01, 1967
Accession Number
AD0658049

Entities

People

  • H. Krier
  • J. S. T'ien
  • M. Summerfield
  • William A. Sirignano

Organizations

  • Princeton University

Tags

DTIC Thesaurus Topics

  • Burning Rate
  • Combustion
  • Combustion Chambers
  • Combustors
  • Computers
  • Digital Computers
  • Equations
  • Ignition
  • Propellants
  • Solid Phases
  • Solid Propellants
  • Steady State

Fields of Study

  • Physics

Readers

  • Calculus or Mathematical Analysis
  • Rocket Propulsion.
  • Theoretical Analysis.