Chamber pressure

About: Chamber pressure is a research topic. Over the lifetime, 2988 publications have been published within this topic receiving 30725 citations.

A preliminary design of a magnesium fueled martian ramjet engine

Abstract: This paper presents a preliminary design study for a solid fuel ramjet containing a super-stoichiometric loading of magnesium for operation in the Martian atmosphere. The methods and theory used for analysis are derived from first principles. A feasible ramjet design was obtained which has an operational speed of Mach 4 to 5, requires nine times the mass intake of atmosphere relative to the mass flow rate of solid grain, and a chamber pressure of approximately 250 kPa. The length of the combustion chamber is approximately 0.1 meters for the case of 100-micron diameter magnesium particles, and 3 to 10 meters for the case of 500-micron particles. The ratio of grain burn area to throat area is approximately 17. A suitable inlet design was made which would have nine 8-degree ramps. The inlet height and length would be 0.35 and 1.0 meter, respectively. An end-burning grain design was selected with a burn area of 0.45 m. Hypothetical ballistic values of the magnesium/ sodium nitrate mixture of n=0.15 and a=0.002125 m/s Pa (where the regression rate is br=aPch), produce a thrust of 2900 N and a specific impulse (adjusted for gas augmentation) of 400 seconds. Thrust predictions obtained by varying the ballistic pressure exponent indicate an upper limit above which the thrust curve falls below the drag curve and operation is not possible.

Pressure surge relief system

Abstract: A pressure surge relief system including a valve which is opened to relieve the pipeline when line pressure overcomes a pilot chamber pressure. A pilot load duct with a variable orifice device therein connects the chamber to the pipeline. In the event of a surge, the orifice retards pressure build-up in the chamber so that it will be overcome by higher pressure in the pipeline. Pressure responsive means makes the orifice device more restrictive as pressure increases to produce a pressure lag at the control chamber even at lower velocities.

External combustion rotary piston engine

Abstract: An engine (400) is disclosed and comprises: a compressor (428) which periodically defines a chamber and carries out a pressurization process wherein the chamber volume is decreased to produce pressurized air; a combuster (426) which combusts fuel with the pressurized air to produce primary exhaust; an air motor (408) which is driven by the primary exhaust to produce power and secondary exhaust; an expander (410) which expands the secondary exhaust to produce tertiary exhaust and power; and a shaft (314) which directs power produced by the motor (408) and the expander (410) to the compressor (428) and any load. The combuster (426) is adapted to receive varying amounts of fuel, thereby to vary the power to the load. The compressor (428), during pressurization, releases air from the chamber such that the chamber pressure during pressurization and the primary exhaust pressure is substantially constant at steady state conditions, said constant being a function of the load being driven by the power.

High pressure wafer-less auto clean for etch applications

Abstract: A method for cleaning a processing chamber is provided. The method initiates with introducing a fluorine containing gaseous mixture into a processing chamber. Then, a plasma is created from the fluorine containing gaseous mixture in the processing chamber. Next, a chamber pressure is established that corresponds to a threshold ion energy in which ions of the plasma clean inner surfaces of the processing chamber without leaving a residue. A method for substantially eliminating residual aluminum fluoride particles deposited by an in-situ cleaning process for a semiconductor processing chamber and a plasma processing system for executing an in-situ cleaning process are also provided.