Showing papers on "Ullage published in 2001"

Fluid dispenser having a housing and flexible inner bladder

Abstract: A dispenser for dispensing a fluid includes a rigid vial that has a main fluid chamber containing a fluid, and a pump assembly that is in fluid communication with the main fluid chamber and is configured to dispense a predetermined quantity of fluid from the main fluid chamber. A flexible bladder is provided which is located within the main fluid chamber and is configured to expand to fill the ullage created within the main fluid chamber during dispensing of fluid by the pump assembly. The resilient bladder tends to force itself outwardly toward the rigid vial and, in turn, increases the pressure within the main fluid chamber in comparison to the interior of the bladder to thereby prevent the ingress of air or vapors through the bladder or otherwise into the main fluid chamber.

Numerical Modeling of Pressurization of a Propellant Tank

Abstract: An unsteady finite volume procedure has been developed to predict the history o pressure, temperature and mass flow rate of the pressurant and propellant during the expulsion of the propellant from a tan. The time dependent mass, momentum and energy conservation equations are solved at the ullage space. The model accounts for the change in the ullage volume due to expulsion of the propellant. It also accounts for the heat transfer from the tank wall and propellant to the ullage gas. The procedure was incorporated in the Generalized Fluid System Simulation Program (GFSSP). The results of several test cases were then compared with a published correlation of pressurant requirements for a given displacement of propellant. The agreement between the predictions and the correlation was found to be satisfactory.

Fluid dispenser having a rigid vial and flexible inner bladder

Abstract: A dispenser (10) for dispensing a fluid includes a rigid vial (52) that has a main fluid chamber (55) containing a fluid, and a pump assembly (50) that is in fluid communication with the main fluid chamber (55) and is configured to dispense a predetermined quantity of fluid from the main fluid chamber (55). A flexible bladder (54) is provided which is located within the main fluid chamber (55) and is configured to expand to fill the ullage created within the main fluid chamber (55) during dispensing of fluid by the pump assembly (50). The resilient bladder (54) tends to force itself outwardly toward the rigid vial (52) and, in turn, increases the pressure within the main fluid chamber (55) in comparison to the interior of the bladder (54) to thereby prevent the ingress of air or vapors through the bladder (54) or otherwise into the main fluid chamber (55).

Aircraft environment controller

Abstract: The air in a cabin (2) is taken out and only the oxygen and water molecules contained in this taken-out air are separated out by a selectively permeable membrane (21) and fed back to the cabin (2), while the remaining nitrogen is fed to a fuel tank ullage (41) for protection against explosion This makes it possible to greatly reduce bleed air flow which has been taken in from an engine (1) for passengers' breathing and for protection against explosion

Fluid dispenser with bladder inside rigid vial

Abstract: A dispenser (10) for dispensing a fluid includes a rigid vial (52) that has a main fluid chamber (55) containing a fluid, and a pump assembly (50) that is in fluid communication with the main fluid chamber (55) and is configured to dispense a predetermined quantity of fluid from the main fluid chamber (55). A flexible bladder (54) is provided which is located within the main fluid chamber (55) and is configured to expand to fill the ullage created within the main fluid chamber (55) during dispensing of fluid by the pump assembly (50). The resilient bladder (54) tends to force itself outwardly toward the rigid vial (52) and, in turn, increases the pressure within the main fluid chamber (55) in comparison to the interior of the bladder (54) to thereby prevent the ingress of air or vapors through the bladder (54) or otherwise into the main fluid chamber (55).

Inerting of a Vented Aircraft Fuel Tank Test Article with Nitrogen-Enriched Air

Abstract: : This report documents a series of experiments designed to determine the quantity and purity of nitrogen-enriched air (NEA) required to inert a vented aircraft fuel tank. NEA, generated by a hollow fiber membrane gas separation system, was used to inert a laboratory fuel tank with a single vent on top designed to simulate a transport category airplane fuel tank, The tank ullage space could be heated as well as cooled and fuel could be heated in the bottom of the fuel tank to provide varying hydrocarbon concentrations within the ullage space. Several inerting runs were performed with varying NEA gas purities and flow rates. The data was nondimensionalized in terms of NEA purity, volume flow rate, and fuel tank size to provide one universal inerting curve. Changing temperatures and hydrocarbon concentrations appear to have little effect on the amount and purity of NEA needed to inert the test specimen. A model of ullage washing developed by the Federal Aviation Adiministration Chief Scientific and Technical Advisor for fuel systems design, based on the volume exchange of gases of different concentrations, was compared with data obtained from the test article. Also, an exact solution based on uniform and instantaneous mixing was derived and compared with the test data. Both the model and exact solution showed good agreement in both trend and magnitude with the data obtained during the testing.

Fuel additive controlling and maintaining apparatus

Abstract: A fuel additive controlling and maintaining apparatus used to eliminate the loss of absorbed CO 2 gas mixed into liquid hydrocarbon fuel and particularly diesel fuel. In addition to the gas-enriched fuel, a gastight bag is utilized for holding a stabilizing gas mixture of CO 2 and air that is not absorbed in the fuel. This bag, which is located within a protective enclosure and is connected into the ullage of a fuel tank, via a conduit, has approximately the same volume as the fuel tank. A two product refueling means is provided so that gas-enriched fuel is delivered to the fuel tank and the CO 2 gas is delivered to the gastight bag. During fuel usage, as the fuel tank ullage increases, the gas mixture from the gastight bag maintains the ullage in a substantially filled condition thus, allowing the fuel to remain gas-enriched.

Zero Gravity Cryogenic Vent System Concepts for Upper Stages

Abstract: The capability to vent in zero gravity without resettling is a technology need that involves practically all uses of sub-critical cryogenics in space, and would extend cryogenic orbital transfer vehicle capabilities. However, the lack of definition regarding liquid/ullage orientation coupled with the somewhat random nature of the thermal stratification and resulting pressure rise rates, lead to significant technical challenges. Typically a zero gravity vent concept, termed a thermodynamic vent system (TVS), consists of a tank mixer to destratify the propellant, combined with a Joule-Thomson (J-T) valve to extract thermal energy from the propellant. Marshall Space Flight Center's (MSFC's) Multipurpose Hydrogen Test Bed (MHTB) was used to test both spray-bar and axial jet TVS concepts. The axial jet system consists of a recirculation pump heat exchanger unit. The spray-bar system consists of a recirculation pump, a parallel flow concentric tube heat exchanger, and a spray-bar positioned close to the longitudinal axis of the tank. The operation of both concepts is similar. In the mixing mode, the recirculation pump withdraws liquid from the tank and sprays it into the tank liquid, ullage, and exposed tank surfaces. When energy extraction is required, a small portion of the recirculated liquid is passed sequentially through the J-T expansion valve, the heat exchanger, and is vented overboard. The vented vapor cools the circulated bulk fluid, thereby removing thermal energy and reducing tank pressure. The pump operates alone, cycling on and off, to destratify the tank liquid and ullage until the liquid vapor pressure reaches the lower set point. At that point, the J-T valve begins to cycle on and off with the pump. Thus, for short duration missions, only the mixer may operate, thus minimizing or even eliminating boil-off losses.

Gear pump for rubber extrusion

Abstract: PROBLEM TO BE SOLVED: To provide a gear pump capable of freely controlling rubber ullage. SOLUTION: The gear pump for rubber extrusion is constituted by forming a plural number of recessed channels for rubber flow. The channels extend from each of shaft equivalent positions of each of gears to each of bottom equivalent positions of each of tooth spaces of each of the gears on at least one surface of respective both side surfaces of a pair of the gears and housing inner surfaces directly facing each of these both side surfaces. COPYRIGHT: (C)2002,JPO

Fuel system device with explosion proof function for fuel tank and fuel feed method

Abstract: PROBLEM TO BE SOLVED: To provide a fuel system device with the function of protecting a fuel tank against explosion for keeping ullage oxygen concentration in a fuel tank at a preset reference value or less without scavenging ullage during flying by removing oxygen dissolved in a fuel to be fed to the fuel tank and in a fuel in the fuel tank, and a fuel feed method. SOLUTION: The fuel system device 10 comprises aspirator/scrubber 20 located via a feed passage 13 for guiding the fuel from a fuel feed source 100 to the fuel tank for reducing the oxygen concentration of the fuel to be fed, a circulation passage 14 for guiding the fuel in the fuel tank 30 to the upstream side in a direction A of feeding the fuel beyond the aspirator/scrubber 20 of the feed 13, and a control part 17 for controlling a first valve 11 and a pump 15 to circulate the fuel in the fuel tank 30 via the circulation passage 14 after feeding the fuel from the fuel feed source 100 to the fuel tank 30.

Proton ullage motor observations as possible precursors to explosions in space

Abstract: Two optical observation campaigns during 1999 and 2000 were conducted to monitor the optical characteristics of the Proton 4 ullage motor population located in mainly geostationary transfer orbits about the earth. This study attempted to physically characterize the intact ullage motors and those that have exploded in space using conventional large aperture binocular optics and 3rd generation image intensified video (commonly employed for non-military astronomical observation) in order to determine if optical signatures could reveal evidence as to which motors might be candidates for explosion. We find that some motors do not spin down through normally expected damping; explosions do not consistently result in the catastrophic destruction of the parent body involved; accelerations in the rotation rates of some intact ullage motors have been discovered; some fragmentations do not result in an increase in rotation of the surviving parent as might be expected. No conclusive evidence was obtained that could lead to positively identifying precursors for future explosion. Yet, through statistical methodology we determined that there is a strong probability of additional explosions until the majority of motors launched between 1982 and 1996 decay from orbit. We estimate the probability of at least one of 46 ullage motors currently in orbit exploding before decay is greater than 0.9999. The threat of explosions is not expected to be mitigated by natural decay of all candidate exploders for at least 50 years.

Ullage meter for a tank of compressed gas at elevated temperature

Abstract: A method of gas tank ullage indication is designed to be made up of a coating or film attached to the surface of a tank for holding compressed gas. This is used normally when the tank is warm as is the case right after the tank is pressured with gas. The coating includes materials which change in appearance when various specific temperatures are reached. The changed appearance allows indications to be seen that tell the observer how the pressure will change after the tank has equilibrated to some specific temperature.

Cryogenic liquid storage tank includes an ullage tank disposed within main tank and has opening where pipe segment is connected

Abstract: The tank (10) comprises of main tank (12) for receiving liquid via fill pipe (22) Ullage tank (30) disposed within main tank and has opening (32) where pipe segment (36) is connected for conveying liquid between bottom of ullage to top of main tank Pipe segment has effective flow rate less than fill pipe such that ullage tank does not fill with liquid unit after main tank is filled and empties faster than main tank as liquid is dispensed from main tank due to pressure differential between tanks