University of Washington

Washington Research Foundation

Carl Knowlen

Adam P Bruckner

Viggo K Hansen

Andrew J Higgins

Viggo Hansen

Abraham Hertzberg

Carl John Stevens

Arthur T Mattick

David W Bogdanoff

Keith A McFall

Carl J Stevens

Robert Cerff

A baffled ram accelerator system includes a ram accelerator tube with an inner surface and an outer surface and a plurality of baffles disposed on the inner surface. The plurality of baffles forms a sequential series of propellant chambers along the longitudinal axis of the ram accelerator tube. An accelerator gun is also disposed on an input end of the ram accelerator tube, and the accelerator gun is positioned to fire a projectile into the ram accelerator tube.

Baffled-tube ram accelerator

Apparatuses and associated methods for forming olefins from saturated hydrocarbon feedstock are disclosed herein. In one embodiment, a carrier gas is introduced at a supersonic velocity to a feedstock injector section. A feedstock gas is introduced to the carrier gas stream using feedstock injectors that are offset in the streamwise direction one from another. The upstream feedstock injectors are positioned to inject feedstock gas to create plumes that improve penetration depth of the feedstock gas and reduce pressure losses at the downstream feedstock injectors. The feedstock gas can be regeneratively preheated by cooling the convergent-divergent nozzle. Water, steam and/or hydrogen gas can be injected into the apparatus for cooling the throat of the convergent-divergent nozzle.

Supersonic shock wave reactors, and associated systems and methods

A method and apparatus for initiating a ram acceleration of a projectile that is at rest. A projectile (34) is positioned in a starting chamber (14) of a launch tube (12). Starting chamber (14) is either filled with a gas at a relatively low pressure or is substantially evacuated. A wave reflection disk (42/42') is positioned a short distance behind the projectile. Downstream of the starting chamber are a plurality of segments, including a first segment (16), which is filled with a combustible gas mixture at a substantially higher pressure than that in the starting chamber. The first segment is separated from the starting chamber by a pair of thin membranes (20a and 20b). These membranes have a characteristic burst pressure that is about midway between the differential pressure in the first segment and the starting chamber. To initiate the ram acceleration process, fluid between the two membranes is exhausted to the atmosphere, sequentially exposing them to a differential pressure that exceeds their burst pressure. Bursting of these membranes enables the combustible gas mixture to expand unsteadily from the first segment into the starting chamber. An expansion wave produced by the expanding combustible gas mixture passes the projectile and reflects from the wave reflection disk as a shock wave. The wave reflection disk converts the kinetic energy of the expanding gas into thermal energy, at a temperature sufficient to initiate combustion of the mixture. The shock wave propagates downstream from the wave reflection disk, attaches to the projectile, and establishes a stable, thermally choked ram acceleration of the projectile down the launch tube. As the combustible gas mixture burns behind the projectile, the resulting pressure wave accelerates the projectile down the bore of the tube into successive combustible gas-filled segments.

Method and apparatus for zero velocity start ram acceleration

A method and apparatus for supersonically accelerating a projectile in a thermally choked subsonic combustion mode. A projectile (50) is initially preaccelerated using either a tank (24) of compressed helium or a chemical propellant charge preaccelerator (152). The projectile enters a portion of a tube (22) filled with a combustible mixture (54) of a gaseous fuel and an oxidizer and is propelled by a ram acceleration process as the mixture burns. In several different embodiments, various devices are used to control the velocity of a shock wave generated as the projectile enters the combustible mixture and the dynamic impulse pressure immediately behind the projectile, so that the shock wave attaches to the projectile along an aft portion, thereby establishing a stable subsonic combustion zone along the aft end (64) of the projectile, in which combustion of the gaseous fuel accelerates the projectile down the bore of the tube. In one embodiment, a perforated sabot (52) is used to propel the projectile during preacceleration. The sabot has a plurality of passages (114) extending longitudinally between its front and rear surfaces, which are initially closed with a thin plate (110) during the preacceleration of the projectile. However, the plate is dislodged as the projectile enters the combustible mixture, allowing the dynamic pressure of the shock wave caused by the sabot to dissipate through the open passages.

Method and apparatus for initating stable operation of a ram accelerator

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Seattle, WA, United States of America

Carl Knowlen