Pulse detonation propulsion: challenges, current status, and future perspective

The article of record as published may be found at http://dx.doi.org/10.1016/j.pecs.2004.05.001The paper is focused on recent accomplishments in basic and applied research on pulse detonation engines (PDE) and various PDE design concepts. Current understanding of gas and sprary detonations, thermodynamic grounds for detonation-based propulsion, principles of practical implementation of the detonation-based thermodynamic cycle, and various operational constraints of PDEs are discussed

Measurement of submicrometer Al2O3 particles in plumes

Applied Optics, Volume 32, No. 33, pp. 6834-6840 (20 November 1993)We made multiple-wavelength light transmission measurements at the edge of a plume from a small solid-propellant motor in order to determine the mean particle size and the in situ particle index of refraction. We retrieved the particle size distribution from the Sauter mean diameter and the geometrical standard deviation assuming a lognormal distribution. The good correlation of the data indicated the applicability of the technique with a relatively high confidence level and that submicrometer particles were dominantly present at the edge of the plume..

Combustion behavior of solid fuel ramjets

Nonreacting flowfield characteristics and fundamental fuel properties are considered with respect to their use in estimating the obtainable combustion efficiency for fuels and/or combustor geometries. It is shown that near wall turbulence intensity in nonreacting flow appears to correlate reasonably well with the fuel regression pattern in identical geometries. The HTPB based fuels exhibit solid phase exothermic reactions in contrast to purely endothermic reactions for plexiglas. It is further shown that combustion pressure oscillations appear to be related to physically induced disturbances to the fluctuating shear layers at the fuel grain and aft mixing chamber inlets.Approved for public release; distribution is unlimited