Showing papers on "Ullage published in 1988"

Liquid volume monitoring apparatus and method

Abstract: An apparatus (9) is disclosed for determining the volume of liquid (18) in a container (1) which is being provided with an in flow and an out flow of liquid such that there normally remains an ullage volume (8) in the container filled with gas. A timer (13) actuated valve (11) is provided for interrupting one of the in flow and the out flow of liquid. A pressure sensor (10) detects the pressure of the gas in the ullage volume (8) of the container (1) during the interruption of the one of the in flow and out flow of the liquid, and a microprocessor (14) calculates the volume of liquid (18) in the container (1) from the detected change in pressure of the gas during the interruption. The apparatus and associated method are particularly advantageous for determining the volume of liquid in a liquid reservoir of an integrated drive generator of an aircraft engine since the determination of the liquid volume can be accomplished with the reservoir of irregular shape in various attitudes, at various temperatures and under conditions of acceleration and minimal additional weight being added to the aircraft.

Jet Fuel Deoxygenation

Abstract: : This program was initiated to identify and characterize methods of deoxygenating quantities of jet fuel to improve fuel thermal stability. Three methods, chemical getters, molecular sieves and nitrogen sparging, were evaluated in our laboratory. In the case of nitrogen sparging, additional results were obtained by comparing laboratory experimental results with the output from ULLAGE, a computer based mathematical model. Each method was shown to reduce the oxygen content of jet fuel. Economic and system considerations favor nitrogen sparging for large quantities of fuel. Jet fuels, Deoxygenation.

Turbo hydraulic unitized actuator

Abstract: A propulsion system (10) having a propulsion engine (18) which combusts propellant received from a storage tank (12) in which a portion (14) of the tank contains propellant in a liquid state and in which an ullage (16) in a remaining portion of the tank contains the propellant in a gaseous state is disclosed A first propellant circuit couples liquid propellant stored in the portion of the tank storing the propellant in a liquid state to an evaporator (22) for gasifying the liquid propellant A second propellant circuit couples the gaseous propellant from the evaporator to the propulsion engine for combustion by the engine and to the ullage A turbine (24) is disposed in the second propellant circuit coupling the gaseous propellant from the evaporator to the propulsion engine and to the ullage between the evaporator and the ullage for providing a power takeoff (26) powered by energy of the gaseous propellant flowing in the second circuit The invention achieves a weight savings over the prior art auxiliary power unit and utilizes energy for direction control which previously had not been used for any purpose

Liquid sensor with high sensitivity near empty

Abstract: A fuel or fluid level measurement arrangement for a spacecraft includes one or more electromagnetic transmission lines extending into the reservoir. The presence of fuel adjacent the transmission line changes the dielectric constant or loss characteristics of the transmission line(s) in a measurable manner. In one embodiment, strip transmission lines extend parallel to the fluid surface at various degrees of ullage, and the fuel level can be established to within the spacing between the transmission lines.

Fuel bath volume compensator for stored chemical energy power propulsion system

Abstract: An ullage compensator is disclosed for a stored chemical energy power propulsion system. With the invention, at least one movable wall (16) is provided within a reactor having a chamber (10) which is movable between a first position at which the chamber has a maximum reaction volume to a second position at which the reaction chamber has a minimum volume. A force is applied to the movable wall by a bellows to cause the wall to project into the chamber in response to the force when a reaction is occurring within the chamber. The invention eliminates damage to the interior surface of the chamber and the inlet port(s) for introducing an oxidant into the chamber which sustains the reaction caused by direct contact with a gaseous oxidant which causes the reaction.

Assessment of the hydrogen external tank pressure decay anomaly on Space Transportation System (STS) 51-L

Abstract: Following the Challenger tragedy, an evaluation of the integrated main propulsion system flight data revealed a premature decay in the hydrogen external tank ullage pressure. A reconstruction of predicted ullage pressure versus time indicated an inconsistency between predicted and measured ullage pressure starting at approximately 65.5 seconds into the flight and reaching a maximum value between 72 and 72.9 seconds. This discrepancy could have been caused by a hydrogen gas leak or by a liquied hydrogen leak that occurred either in the pressurization system or in the external tank. The corresponding leak rates over the time interval from 65.5 to 72.9 seconds were estimated to range from 0.28 kg/s (0.62 lbm/s) + or - 41 percent to between 0.43 and 0.51kg/s (0.94 and 1.12lbs/s) + or - 1 percent for a gas leak and from 72.9 kg/s (160.5 lbs/s) + or - 41 percent to between 111.6 and 133.2 kg/s (245.8 and 293.3 lbs/s) + or - 1 percent for a liquid leak. No speculation is made to ascertain whether the leak is liquid or gas, as this cannot be determined from the analysis performed. Four structural failures in the hydrogen external tank were considered to explain the leak rates. A break in the 5-cm (2 in) pressurization line, in the 13-cm (5 in) vent line, or in the 43-cm (17 in) feedline is not likely. A break in the 10-cm (4 in) recirculation line with a larger structural failure occurring in the 72 to 73-second time period, the time of the visibly identified premature pressure decay, does seem plausible and the most likely of the four modes considered. These modes are not all-inclusive and do not preclude the possibility of a leak elsewhere in the tank.

An Electronic Balance for Weighing Foams at Cryogenic Temperatures

Abstract: A commercial electronic balance was altered to weigh objects in a cryogenic environment containing combustible fluids. The balance was used to measure the mass gain of open cellular foams touching the surface of liquid hydrogen. The mass gain rate is a function of the foam wicking characteristics (a function of the foam structure). Weighing the empty and liquid filled foam sample in the ullage above the liquid, and the foam submerged in the liquid, gives sufficient information to allow a free volume or porosity to be determined for the foam. These tests are especially important for foams too weak to withstand the surface tension forces of ambient temperature liquids. Details of the design of the cryogenic balance and some results for several types of foams are presented in this paper.