NTRS - NASA Technical Reports Server

Back to Results
Coated oxidizers for combustion stability in solid-propellant rocketsExperiments are conducted in a laboratory-scale (6.25-cm diameter) end-burning rocket motor with state-of-the-art, ammonium perchlorate hydroxy-terminated polybutadiene (HTPB), nonmetallized propellants. The concept of tailoring the stability characteristics with a small amount (less than 1 percent by weight) of COATING on the oxidizer is explored. The thermal degradation characteristics of the coat chemical are deduced through theoretical arguments on thermal diffusivity of the composite material (propellant). Several candidate coats are selected and propellants are cast. These propellants (with coated oxidizers) are fired in a laboratory-scale end-burning rocket motor, and real-time pressure histories are recorded. The control propellant (with no coating) is also tested for comparison. The uniformity of the coating, confirmed by SEM pictures and BET adsorption measurements, is thought to be an advance in technology. The frequency of bulk mode instability (BMI), the pressure fluctuation amplitudes, and stability boundaries are correlated with parameters related to the characteristic length (L-asterisk) of the rocket motor. The coated oxidizer propellants, in general, display greater combustion stability than the control (state-of-the-art). The correlations of the various parameters are thought to be new to a field filled with much uncertainty.
Document ID
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Helmy, A. M.
(Teledyne McCormick Selph Hollister, CA, United States)
Ramohalli, K. N. R.
(Arizona, University Tucson, AZ, United States)
Date Acquired
August 12, 2013
Publication Date
July 1, 1985
Subject Category
Propellants And Fuels
Report/Patent Number
AIAA PAPER 85-1111
Accession Number
Funding Number(s)
Distribution Limits

Available Downloads

There are no available downloads for this record.
No Preview Available