Showing papers on "Burn rate (chemistry) published in 1968"

An optical bomb study of the combustion of solid propellants in high acceleration fields

Abstract: : Under the subject program, an experimental study of the effects of acceleration fields on the burning rate of solid propellant grains is being conducted. The general plan is to investigate a variety of formulations over a range of pressures and acceleration loadings, the results to be used to evaluate theoretical models of the process or to form the basis for improved models. In this report the results for two formulations are presented. The acceleration vector in these tests, produced by spinning a disc-shaped grain, was directed normal to and away from the surface. For one of the propellants, which contained only CTPB binder and AP, the burning rate decreased approximately 20 percent at g-loadings of 500. At higher accelerations levels up to 1600 g's an additional 10 percent decrease appeared to occur, although the changes were too small to be determined with certainty. For a second propellant, similar to the first but containing 12 percent powdered aluminum, the change in burning rate if it existed at all was too small for any consistent trend to be detected at g- levels up to 2000. For both propellants the effects were independent of pressure up to 50 atm.

Combustion tailoring criteria for solid propellants.

Abstract: : The objective of this research program is to develop an analytical model describing the steady-state combustion of solid propellants which is suitably equipped to provide combustion tailoring criteria for both state-of-the-art and advanced propellant formations. Tests with small samples of propellants will provide experimental data for modeling the propellant combustion process for different ingredient variations. Additional tests simulating the environment of a rocket motor will provide experimental data showing the effect of rocket motor environment upon the combustion process. During Phase III, work was directed toward developing the analytical model and modifying aspects of the model. A list of propellants was chosen for study in tests to be conducted during the remainder of the research program. Small samples of a CTPB/AP propellant were burned in a pressurized combustion bomb and extinguished by rapid depressurization of the bomb. The surface structure was examined through a 10X - 80X microscope. Results from tests conducted in apparatus simulating the environment of a rocket motor (slab combustor) and using a CTPB/AP/A1 propellant showed that the thermal environment of the combustor reaches a maximum level at 200 psia. To learn what effect the thermal environment has upon the propellant burning rate, a technique was developed to directly measure burning rate in the slab combustor. The approach uses a high-speed camera to record the movement of the propellant burning surface with respect to a reference scale.

Rocket burn rate testing device

Abstract: A closed chamber designed to hold one or more strands of a solid propellant is equipped with igniting means, pressure indicating means, and burning rate indicating means. The apparatus avoids the problems inherent in static burning rate tests using an inert pressurizing gas.