Patent ID: 6446428
Filing Date: 2002-09-10
Classification: F02K,F05D

Abstract:
A pulsed denotation engine comprising:(a) an initiator tube fueled with a detonable, enhanced fuel-oxidizer mixture having an associated critical diameter, the tube having a length sufficient to accelerate a deflagration into a detonation; (b) a detonation chamber having a longitudinal axis and having an integral divergent inflow transition section and an open outlet end, the divergent inflow transition section having a first end in fluid communication with, and a diameter roughly equivalent to the diameter of the initiator tube, and a second end in fluid communication with, and a cross section roughly equivalent to the cross section of the interior of the detonation chamber, the divergent inflow transition section having a diverging shape extending from the first end to the second end that enables a detonation to transition from the initiator tube into the detonation chamber, wherein the divergent inflow transition section has a contoured trumpet shape extending from the first end to the second end, the shape having a rate of divergence along its longitudinal axis essentially defined as &dd;Deff&dd;x=2&it;â€ƒ&it;tan&it;{Ï€2+16&it;sin-1&af;(2&it;DeffDcrit-1)}wherein x represents a particular coordinate along the longitudinal axis of the transition section, Dcrit represents the critical diameter of the fuel-oxidizer mixture at coordinate x, and Deff represents the effective diameter, Deff=4&it;AÏ€,wherein A is the cross-sectional area of the divergent inflow transition section at coordinate x;(c) means for admitting an amount of un-fueled buffer oxidizer into the initiator tube and un-fueled buffer air into the transition section and the detonation chamber; (d) means for admitting fuel and oxidizer into the initiator tube, the transition section and the detonation chamber producing a detonable fuel-air mixture inside the initiator tube, the transition section and the detonation chamber; (e) means for igniting the enhanced fuel-oxidizer mixture contained within the initiator tube creating a deflagration propagating through the initiator tube and accelerating into a detonation wave being fueled by the enhanced fuel-oxidizer mixture, the detonation wave propagating through the initiator tube and transitioning over the divergent inflow transition section into the detonation chamber, the detonation wave being fueled by the detonable fuel-air mixture and propagating through the detonation chamber along its longitudinal axis and exhausting out the outlet end, wherein the detonation wave generates a high pressure gas behind the detonation wave that expands and produces thrust in a direction opposite to the exhaust.