Authors: H. D. Perkins and C. J. Sung
Direct link to the paper: http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20020081294_2002137191.pdf
A pulse detonation engine uses a series of high frequency intermittent detonation tubes to generate thrust. The process of filling the detonation tube with fuel and air for each cycle may yield non-uniform mixtures. Uniform mixing is commonly assumed when calculating detonation tube thrust performance. In this study, detonation cycles featuring idealized non-uniform H2/air mixtures were analyzed using a two-dimensional Navier-Stokes computational fluid dynamics code with detailed chemistry. Mixture non-uniformities examined included axial equivalence ratio gradients, transverse equivalence ratio gradients, and partially fueled tubes. Three different average test section equivalence ratios were studied; one stoichiometric, one fuel lean, and one fuel rich. All mixtures were detonable throughout the detonation tube. Various mixtures representing the same average test section equivalence ratio were shown to have specific impulses within 1% of each other, indicating that good fuel/air mixing is not a prerequisite for optimal detonation tube performance under conditions investigated.
Citation: H. D. Perkins and C. J. Sung, “Effects of Fuel Distribution on Detonation Tube Performance”, Journal of Propulsion and Power 21 (3), 539-545 (2005).