AN OPTICAL BOMB STUDY OF THE COMBUSTION OF SOLID PROPELLANTS IN HIGH ACCELERATION FIELDS

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.