Chamber pressure

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

Combustion Dynamics of an Extreme Fuel-Rich Throttleable Rocket Engine During Continuously Throttling Process

Abstract: An experimental study has been conducted to investigate the dynamics of an extreme fuel-rich throttleable rocket engine during continuously throttling process. The rocket engine burned kerosene (RP-1) and oxygen and it was continuously throttled in fire tests by adjusting the flow rate of kerosene. Dynamic response of chamber pressure was analyzed. Results show two phenomena named hysteresis of characteristic velocity and anti-regulation of chamber pressure during the throttling process. When characteristic velocity hysteresis occurs, transient characteristic velocity is higher in condition of increasing mixture ratio (MR) and lower in condition of decreasing MR than steady value during throttling process. The anti-regulation can be induced by throttling or purging process. In addition, both throttling method and throttling rate influence the amplitude and duration of anti-regulation. Finally, the response of chamber pressure to the throttling was divided into two periods, namely ramp response and...

Cyclic speed control apparatus in variable stroke machines.

Abstract: A free piston engine includes speed control means which provide a wide range of engine speed control for selective connection and use of the engine with any one of a number of different types of energy absorbing devices. The desired control is achieved by use of two bounce chambers (18p and 18n) and a double-acting bounce piston unit (16) specifically located at an intermediate position along the axis of reciprocation of the piston rod assembly of such an engine, i.e. between a power piston (15) at one end of the piston rod and a connecting means at the other piston rod end for driving connection of the piston rod assembly with a movable member (e.g. reciprocating compressor piston (34) or reciprocating electric generator member) of the selected energy absorbing device. The control means further includes at least one pair of variably adjustable bounce chamber pressure control valves (23 and 24), one for each bounce chamber. Each control valve of such one pair provides for and controls a direct connection of its respective bounce chamber to ambient atmospheric air outside the bounce chamber. The controls further include sensing means (37) responsive to changes in demands on or operation of the selected energy absorbing device for variably and substantially simultaneously adjusting each control valve of such one pair and thereby similarly changing (i.e. both upwardly or both downwardly) the respective bounce chamber working pressures. Other bounce pressure control features are also described.

Liquid chemical supply device

Abstract: PROBLEM TO BE SOLVED: To provide a liquid chemical supply device capable of accurately delivering liquid chemical and monitoring leak of incompressible medium from a section between a piston and a cylinder SOLUTION: A pump 11 includes a flexible tube 16 dividing a pump chamber 17 and a drive chamber 1, and the incompressible medium 38 is supplied to the drive chamber 18 by a piston 34 reciprocating in a cylinder bore 33 of a cylinder A bellows cover 64 is provided between the piston 34 and the cylinder 12, and a seal chamber 63 connecting to a slide surface of the piston 34 is formed by the bellows cover 64 A seal chamber pressure sensor 71 is mounted on the cylinder 12 to detect pressure of incompressible medium 38a for sealing sealed in the seal chamber 63, degree of deterioration of a seal material 69 is judged by detecting pressure in the seal chamber 63 COPYRIGHT: (C)2008,JPO&INPIT

Chamber Wall Heat Flux Measurements for a LOX/CH 4 Uni-element Rocket

Abstract: Wall heat flux measurements in a 1.0 in. diameter circular cross-section rocket chamber for three uni-element injector elements operating on liquid oxygen (LOX) / gaseous methane (GCH4) propellants are presented. The wall heat flux measurements were made using a rocket chamber instrumented with coaxial thermocouples. Wall heat flux measurements were made for three uni-element injectors, viz., two versions of a shear coaxial element and a swirl coaxial element. The three injectors were designed for a chamber pressure of 1200 psia, LOX flowrate of 0.7 lbm/s and mixture ratio of 3.0. Experiments were conducted at the design pressure of 1200 psia and also at reduced pressures of 1000, 800, 600 and 300 psia for each injector at the design mixture ratio of 3.0 and also at 2.5 and 3.25. For experiments at the lower pressures, the propellant mass flowrates were scaled down linearly. The local wall heat flux measurements show higher heat flux levels for the swirl coaxial injector than the two versions of the shear coaxial injector at near injector face locations. This is attributed to enhanced LOX atomization, mixing and combustion provided by the conical swirling spray in the near injector face region for the swirl coaxial injector. The two tested shear coaxial injectors differ in the design fuel-to-oxidizer momentum flux ratios. The shear coaxial injector with the higher fuel-to-oxidizer momentum flux ratio showed higher heat flux levels in the near injector face region. One of the two shear coaxial injectors was designed such that the LOX post could be configured flush or recessed with respect to the injector face. The configuration with the LOX post recessed showed higher heat flux levels in the near injector face region than its LOX post flush counterpart, indicating that the mixing cup provided by recessing the LOX post has a positive effect on the mixing and combustion characteristics of the injector. Finally, the axial wall heat flux profiles for different chamber pressures were scaled with respect to chamber pressure to the power 0.8. The scaling brought the profiles closer together but not to the extent of collapsing the data, indicating that for liquid/gas injectors where the fuel-to-oxidizer momentum flux ratio decreases with chamber pressure, the resulting coupled atomization/mixing/combustion phenomena does not scale simply with pressure.

Apparatus and method for manufacturing particles

Abstract: The present invention relates to an apparatus and method for manufacturing solid particles based on inert gas evaporation, where the method comprises forming a continuous gaseous feed flow comprising a saturated vapour of the material, and injecting the continuous gaseous feed flow through an inlet into a free-space region of a reactor chamber in the form of a feed jet flow protruding from the inlet, and forming at least one continuous jet flow of a cooling fluid and injecting the at least one jet flow of cooling fluid into the reaction chamber, wherein the feed jet flow is made by passing the feed flow at a pressure above the reactor chamber pressure in the range from 0.01 · 105 to 20 · 105 Pa through an injection nozzle functioning as the reactor inlet and which has a rectangular cross-sectional area of the nozzle opening with height Afeed and width Bfeed, where the aspect ratio Bfeed/Afeed is ≥ 2: 1, and the height A is in the range from 0.1 to 40 mm, and each of the at least one jet flow of cooling fluid is made by passing the cooling fluid through an injection nozzle which directs the jet flow of cooling fluid such that it intersects the feed jet flow with an intersection angle between 30 and 150°, and where each of the at least one jet flow of cooling fluid, either individually or combined, mixes with substantially all of the gas of the feed jet flow at an intended distance apart from the nozzle opening for injection of the feed jet flow.