Showing papers on "Ullage published in 1970"
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04 Feb 1970
TL;DR: In this paper, an apparatus for determining the quantity of liquid in a closed reservoir containing a liquid and an ullage gas was proposed, where an enclosed gas filled cavity communicates with the reservoir through a common elastomeric diaphragm surface.
Abstract: An apparatus for determining the quantity of liquid in a closed reservoir containing a liquid and an ullage gas. An enclosed gas filled cavity communicates with the reservoir through a common elastomeric diaphragm surface. Infrasonic pressure signals directed into the cavity from a variable frequency driving means cause the ullage gas and the diaphragm to resonate at a frequency proportional to the volume of ullage gas in the reservoir. The ullage volume and therefore the remaining liquid volume is proportional to the ullage gas pressure and the resonant frequency.
33 citations
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TL;DR: Cylindrical propellant tanks dynamic stability and parametric resonance, analyzing axial preload, liquid depth, top impedance and ullage pressure by Donnell theory were analyzed in this article.
Abstract: Cylindrical propellant tanks dynamic stability and parametric resonance, analyzing axial preload, liquid depth, top impedance and ullage pressure by Donnell theory
20 citations
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14 citations
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01 Nov 1970
TL;DR: In this article, the effects of liquid fuel motion on the flammability of hydrocarbon turbine fuels in aircraft fuel tanks were investigated. And the major effect of fuel slosh and vibration was to lower or abolish the lean flammabile temperature limit of the fuel.
Abstract: : The report deals with the effects of liquid fuel motion on the flammability of hydrocarbon turbine fuels in aircraft fuel tanks. Three military turbine fuels, JP-4, JP-5, and JP-8, were used in the testing. The fuels were placed in an explosion proof cylindrical test vessel (80-gallon capacity) and subjected to slosh and vibration. An electric arc was formed within the ullage which ignited any flammable fuel-air mixture present. The pressure rise from combustion was measured and correlated with initial conditions. The major effect of fuel slosh and vibration was to lower or abolish the lean flammabile temperature limit of the fuel. The rich flammable temperature limit was unchanged. An analysis was performed on these results and an explanation proposed based upon the hypothesis that all the fuel vapor in the ullage burns for combustion below the flash point.
13 citations
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16 Feb 1970TL;DR: In this article, the explosion hazard is minimized by continuously spraying a liquid comprising predominantly at least one component of the reaction medium into the ullage space so as to maintain a suspension of liquid droplets throughout the ULLAGE space.
Abstract: In a process in which a gas comprising oxygen is bubbled through a liquid reaction medium contained in a reaction vessel, with a flammable or potentially flammable vapor being contained in the ullage space of the vessel with a resultant explosion hazard, the explosion hazard is minimized by continuously spraying a liquid comprising predominantly at least one component of the reaction medium into the ullage space so as to maintain a suspension of liquid droplets throughout the ullage space.
8 citations
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03 Feb 1970
TL;DR: In this article, an injector is provided to deliver into the supply pipe a mixture of the liquid with gas from the ullage space in the top of the container, and the evaporator is provided with a valve for automatically reducing the flow of refrigerant to it in response to the level of liquid in it.
Abstract: In a cryogenic refrigerating apparatus comprising a supply of refrigerating liquid in a Dewar flask, connected through a long flexible supply pipe to an evaporator for cooling a load, an injector being provided to deliver into the supply pipe a mixture of the liquid with gas from the ullage space in the top of the container. The evaporator is provided with a valve for automatically reducing the flow of refrigerant to it in response to the level of liquid in it.
7 citations
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16 Oct 1970
TL;DR: In this article, an elongated guide is provided in the expansion trunk of each of the cargo tanks, the guide being characterized by an open framework which mounts a float for movement toward the ullage opening when the liquid cargo rises in the tank.
Abstract: A system for preventing spillage or overflow of liquid cargo through the ullage openings of cargo tanks of a tanker. An elongated guide is provided in the expansion trunk of each of the cargo tanks, the guide being characterized by an open framework which mounts a float for movement toward the ullage opening when the liquid cargo rises in the tank. The float is engageable with a seat adjacent the opening to seal off the opening and prevent cargo spillage occasioned by inadvertent overfilling. The open framework of the guide permits the ullage opening to still be used to insert a probing element into the cargo tank, the guide preferably being inclined from the vertical for this purpose. Conduits are also provided to convey overflow cargo to empty cargo spaces.
4 citations
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01 Jun 1970
TL;DR: In this paper, a test tank was constructed and mounted on a vibration table, and the fuel ullage was measured with an infrared analyzer, and data were recorded with a fuel/air ratio gradient, which varied from a lean mixture near the top of the tank, due to the inflow of air, to a rich mixture (as high as 12%) near the surface of the fuel due to fuel surface oscillations.
Abstract: : The objective of the research was to study fuel tank ullage characteristics under various atmospheric and dynamic conditions. A test tank was constructed and mounted on a vibration table. The tank was filled with JP-4 fuel and withdrawn at various aircraft usage rates under controlled temperature and vibration. The fuel/air ratio of the ullage was measured with an infrared analyzer, and the data were recorded. A fuel/air ratio gradient was found in the ullage. It varied from a lean mixture (less than 1%) near the top of the tank, due to the inflow of air, to a rich mixture (as high as 12%) near the surface of the fuel, due to fuel surface oscillations. The testing indicates how this gradient is affected by changing the fuel withdrawal rate, fuel temperature, and vibrational excitation frequency. (Author)
4 citations
01 Sep 1970
TL;DR: In this article, the authors evaluated the potential hazard of a simulated helicopter fuel tank and found that fuel/air mixture gradients do exist in fuel tanks under flight conditions, even for level flight.
Abstract: : The objective of the study was to determine fuel tank vapor space characteristics for a simulated helicopter fuel tank and to evaluate the potential hazard which exists. Fuel/air ratios were measured as a function of time and position within the ullage of the fuel tank for specified flight profiles. These results were compared to published flammability limits as a basis for assessing flight hazard potential. The flight profiles were simulated by withdrawing fuel (at rated engine usage) from a vibrating tank held at constant pressure and temperature. Parametric variations were made in fuel temperature (40 to 100F), flight altitude (0 to 15,000 feet), vibration environment, and fuel properties (liquid JP-4 versus JP-4 emulsion EF4-104H). Another important variable not considered initially but which was uncovered during the course of this investigation was the effect that the rubberized tank liner could have on the measured fuel/air ratios. The extent of this effect was found to be related to fuel temperature and exposure time of the liner to the fuel. The experimental results showed those ranges of the test variables which had a significant effect on the measured fuel/air ratios. They also demonstrated that fuel/air mixture gradients do exist in fuel tanks under flight conditions. It was found that tanks which would be considered safe as determined by calculations for equilibrium conditions actually contain flammable regions, even for level flight. An analytical model for the ullage space was written which included transient fuel vapor diffusion and convection which was brought about by venting of the ullage.
4 citations
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TL;DR: The mission of the ULLAGE motor is to maintain a positive acceleration of the Saturn rocket during the period between burnout of the first stage and ignitiion of the second stage.
Abstract: The mission of the ULLAGE motor is to maintain a positive acceleration of the Saturn rocket during the period between burnout of the first stage and ignitiion of the second stage. The eight ULLAGE motors attached to the Saturn second stage are fired during separation from the first stage. They must withstand intense sound levels and vibrations transferred through the first stage and the interstage structures.
2 citations
01 Jan 1970
TL;DR: The effects of partially filled cylinders with attached elastic drain pipe on liquid and ullage gas effects are discussed in this paper, where the authors consider the case of a partially filled cylinder with an elastic drainpipe.
Abstract: Liquid and ullage gas effects of partially filled cylinder with attached elastic drain pipe