COMBUSTION STABILITY RATING TECHNIQUES
Abstract
The objectives of a comprehensive investigation of three techniques for rating the combustion stability of liquid-propellant rocket engines were the establishment of the characteristics of the techniques and of their intercorrelations. The techniques studied were: (1) nondirected explosive bombs, (2) directed explosive pulse guns, and (3) directed flows of inert gases. Characterization was accomplished through cold-flow experiments; each rating device's output pressure, impulse, velocity, etc., were quantitatively correlated to variation of its descriptive parameters, e.g., explosive charge weight, explosive type, burst diaphragm strength, bomb case thickness, etc. Correlations among techniques were sought by applying them at various positions and directs to an operating rocket and measuring the combustor's stability response. Two different propellant injectors were tested with N2O4/N2H4-UDMH (50-50) propellants; one of the injectors was tested with N2O4/UDMH propellants. It was discovered that combustion with these propellants and operating conditions is insensitive to transverse velocity or displacement perturbations; the gas-flow technique initiated no chamber pressure disturbances. However, considerable sensitivity to pressure disturbances from bombs and pulse guns was observed. The combustor's ultimate stability following a pressure perturbation could not be correlated to either bomb or pulse gun parameters or characteristics; recovery to stable operation occurred randomly. The amplitude of the initial pressure wave was correlated quantitatively to both the rating devices' parameters and characteristics.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1966
- Accession Number
- AD0801897
Entities
People
- D. T. Campbell
- E. E. Lockwood
- F. W. Hoehn
- L. P. Combs
- S. R. Webb