Chamber pressure

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

Comparative study of macroscopic spray parameters and fuel atomization behaviour of SVO (Jatropha), its biodiesel and blends

Abstract: The combustion and emission characteristics of vegetable oils and derivatives are quite different from mineral diesel due to their relatively high viscosity, density and vaporisation characteristics. These properties affect the fuel spray and the interaction of the spray with air in the combustion chamber therefore it is important to analyze the spray characteristics e.g. spray tip penetration, spray cone angle, spray area and fuel atomization. Optical techniques for spray visualization and image processing are very efficient to analyse the comparative spray parameters for these fuels. Present research investigates the effect of chamber pressure on spray characteristics of Jatropha SVO (J100)/ blends (J5, J20), and Jatropha biodiesel (JB100)/ blends (JB5, JB20) vis-a-vis baseline data of mineral diesel. Experiments were performed for all these fuels/ blends injected in a constant volume spray visualisation chamber (cold chamber) at four different chamber pressure (1, 4, 7 and 9 bar respectively). It was found that J100 and JB100 have the highest spray tip penetration, cone angle and the spray area followed by J20, J5, mineral diesel and JB20, JB5, mineral diesel respectively however J20, J5 and JB20, JB5 have better atomization characteristics as compared to J100 and JB100 respectively. Cone angle was higher for biodiesel blends as compared to SVO blends at atmospheric pressure however as the chamber pressure was increased to 9 bars, it became almost equal for both fuel types. Spray parameters are found to be excellent for mineral diesel followed by Jatropha biodiesel and Jatropha oil. It was found that atomization of fuel becomes superior with increasing chamber pressure.

Subscale LOX/hydrogen testing with a modular chamber and a swirl coaxial injector

Abstract: To support basic injector and chamber technology, the response of a modular calorimeter chamber to an injector with swirl coaxial elements was investigated. The tests supported both the Advanced Launch System (ALS) and the Space Shuttle Main Engine programs. Original test plans included chamber pressures up to 2250 psia, the current ALS engine criteria, but hardware limitations forced conditions to be reduced. With four different chamber configurations, a variety of data was obtained with chamber pressures ranging from 1483 psia to 1679 psia and mixture ratios from 5.24 to 6.90. The swirl coaxial injector showed good chamber wall compatibility, despite misaligned elements, and its high performance was independent of fuel. Heating rates and wall temperatures were acceptable and close to predict profiles, and after scaling to a chamber pressure of 2250 psia, heating rates remained acceptable. In addition, a chamber spool made with the vacuum plasma spray process survived hot-fire testing with no detrimental effects.

Valve cartridge having pressure sensor for agriculture and weed control

Abstract: An agricultural spray implement includes a plurality of removable valve/filter/nozzle cartridges. Each removable cartridge has a housing that retains a high speed solenoid valve and a spray nozzle. When the solenoid valve is open, an agricultural liquid (for example, herbicide) flows through the solenoid valve, through a chamber in the housing, and through the nozzle. To monitor cartridge operation and/or to detect cartridge failures (for example, a solenoid valve that is stuck open or closed or a nozzle that is clogged), a pressure sensor is provided that detects a pressure in the chamber. A chamber pressure that does not change when the solenoid valve is controlled to open and/or close is indicative of cartridge failure. Operation of each of the many spray cartridges of the agricultural spray implement is monitored from a single display.

Internal stress in ion beam sputtered molybdenum films

Abstract: Stress in molybdenum films deposited by ion beam sputtering has been studied as a function of deposition parameters, such as accelerating voltage, incident angle, and chamber pressure. It has been found that the physical properties of deposited molybdenum films controlled primarily by the ion beam accelerating voltage and substrate orientation with respect to the ion beam. For films deposited at near normal incidence, measured stresses are highly compressive (2–5 GPa) and increase almost linearly with the accelerating voltage (600–1500 V). Under these conditions, deposited molybdenum films exhibit low resistivity and high optical reflectance. As the substrates are rotated to near grazing incidence, measured stress is either negligible or slightly tensile and are almost independent of accelerating voltage. The extremely high resistivity and low reflectance measured indicates the poor quality of the deposited film at grazing incidence. No significant effect was observed when the chamber pressure was varied ...

Experimental investigation of boron combustion in air=augmented rockets

Abstract: Studies have been made using a windowed combustion tunnel to examine the mixing and burning between subsonic air and a supersonic fuel-rich exhaust of a rocket motor burning hydrogen-oxygen-boron mixtures. The reaction processes were recorded by high-speed cinephotography. Results of experiments are presented in which the following parameters were varied: 1) boron concentration in the propellant (up to 55% by weight), 2) nonequilibrium chamber temperature of the primary rocket (750 °K to 2500 °K), and 3) air to propellant flow ratio (3 to 15). The temperature of the primary rocket was calculated by assuming boron as a heat sink. These calculations showed good agreement with experimental data at low chamber temperatures. The strong influence of the primary nonequilibrium chamber temperature on the boron combustion efficiency was demonstrated using the results of particle sampling probes and c*-efficiency measurements. By increasing the chamber temperature from 750°K to 2000°K the over-all reaction efficiency was improved from 85 to 94%.