scispace - formally typeset
Search or ask a question

Showing papers on "Ullage published in 2021"


Journal ArticleDOI
TL;DR: In this article, the effects of ullage height (distance between the fuel surface and the upper pool rim) on fire plume flow and combustion characteristics were conducted by experimental and numerical studies.

13 citations


Journal ArticleDOI
TL;DR: In this paper, the authors present test data analysis of the liquid nitrogen vented chill, no-vent fill (NVF) experiments on the CRYOTE-2 tank, and while not originally intended, were performed in a somewhat parametric fashion.

10 citations


Journal ArticleDOI
TL;DR: In this article, a series of experiments were conducted to reveal the effects of ullage height on the evolution of the heptane fire plume centerline temperature, and a new virtual origin model was established to quantify the effects on the virtual origin.

10 citations


Journal ArticleDOI
TL;DR: In this article, a non-linear diffusion model with forced convection in the form of a reactionabsorption system was provided to produce inerted ullage in an Airbus A320 aircraft center fuel tank.
Abstract: The aim of this work was to provide a formulation of a non-linear diffusion model with forced convection in the form of a reaction–absorption system. The model was studied with analytical and numerical approaches in the frame of the parabolic operators theory. In addition, the solutions are applied to a gas interaction phenomenon with the intention of producing an inerted ullage in an Airbus A320 aircraft centre fuel tank. We made use of the travelling wave (TW) solutions approach to study the existence of solutions, stability and the precise evolution of profiles. The application exercise sought to answer a key question for aerospace sciences which can be formulated as the time required to ensure an aircraft fuel tank is safe (inerted) to prevent explosion due to the presence of oxygen in the tank ullage.

9 citations


Journal ArticleDOI
TL;DR: In this article, the authors investigated the effects of ullage height (distance between the fuel surface and the pool upper rim) on heat feedback and combustion emission mechanisms of heptane pool fires.

5 citations


Journal ArticleDOI
TL;DR: In this paper, an in-flight electrochemical gas separation and inerting system (EGSIS) was proposed to produce and supply nitrogen-enriched air (NEA).

4 citations


Journal ArticleDOI
TL;DR: In this paper, the effect of operation mode on the TVS performance was conducted by using liquid nitrogen as the liquid oxygen simulant on a testing facility named Multi-functional Cryogenic Test System.

3 citations


Journal ArticleDOI
TL;DR: Sensitive analyses carried out on the proposed model show that ground-based inerting can effectively reduce the ullage oxygen, concentration in the climb phase, and increasing 5 min of pre-takeoff inerting duration can shorten the time of decreasing the uLLage oxygen concentration after takeoff.
Abstract: Ullage washing is an efficient inerting method to keep the ullage oxygen concentration under the safe value, thus reducing the hazard and loss of fire and explosion of aircraft fuel tanks. In the conventional model of ullage washing, the initial derivatives of oxygen concentration that are used to solve the differential equations are selected subjectively by researchers and the empirical select influences the accuracy of the result. Therefore, this paper proposes an analytical algorithm that can calculate the ullage oxygen concentration without selecting any initial derivative value. The algorithm is based on a fuel tank ullage washing model regarding various inerting stages. It has been experimentally validated with an average relative error of 5.781%. Moreover, sensitive analyses carried out on the proposed model show that ground-based inerting can effectively reduce the ullage oxygen, concentration in the climb phase. Increasing 5 min of pre-takeoff inerting duration can shorten the time of decreasing the ullage oxygen concentration to 9% after takeoff by 2.1 min.

2 citations


Journal ArticleDOI
TL;DR: In this article, the effect of interfering factors such as heat flux, liquid level and tank ullage pressure on geyser's appearance was explored. And the authors concluded that a clear periodic pressure and temperature change accompanied by periodic plenty vapor ventilation could serve as an indication for geysers occurrence, and the eruption of a cryogenic gusher has a similar appearance as that in the geothermal field.

1 citations


Journal ArticleDOI
TL;DR: In this paper, the key parameters governing the ullage space temperature profile are the heat leak rate, the rate of evaporation of liquid and release of vapor to m...
Abstract: While storing cryogens at atmospheric pressure, the key parameters governing the ullage space temperature profile are the heat leak rate, the rate of evaporation of liquid and release of vapor to m...

1 citations


Patent
01 Jun 2021
TL;DR: A spacecraft includes a propulsion system that includes one or more pressurant tanks configured to store an inert gas at a high pressure, and a propellant tank including an ullage volume pneumatically coupled with at least one of the pressurants by way of a second pressure regulator having an output set to the intermediate pressure as discussed by the authors.
Abstract: A spacecraft includes a propulsion system that includes one or more pressurant tanks configured to store an inert gas at a high pressure, one or more propellant tanks configured to store liquid propellant at an intermediate pressure, electric thrusters operable with the inert gas at a low pressure and pneumatically coupled with the one or more pressurant tanks by way of a first pressure regulator, and chemical thrusters operable with the liquid propellant. The inert gas is one or a mixture of two or more of xenon, argon and krypton. At least a portion of the liquid propellant is stored in at least one of the propellant tanks, the propellant tank including an ullage volume pneumatically coupled with at least one of the pressurant tanks by way of a second pressure regulator having an output set to the intermediate pressure and the ullage volume is pressurized by the inert gas.

Journal ArticleDOI
01 Mar 2021
TL;DR: For long-term use of an ullage monitoring system, it is recommended to use the inside one, although it is more expensive, the simple working principle and easier maintenance making it unlikely to hire experts only for dealing with the sensor nodes.
Abstract: Manual control of wine production possibly can be ineffective, considering in a winery there could be more than one parameter quality control with many tanks or barrels produced at the same time. In the aging process of Fino-style winemaking, the ullage must be maintained at a constant level. Considering the existing barrels and tanks, space is needed to place the sensor to collect data with the best result possible. In the case of sensor placement inside the system, an ultrasonic sensor is used by acquiring the time data needed to receive the signal emitted from the sensor. Whereas in the case of sensor placement outside the system, a microphone is being used to acquire sound frequency data generated from hitting wine cask with solenoids in a sample time of 100ms. Based on the latest research, the two sensors can be used to acquire ullage data from casks. However, for long-term use of an ullage monitoring system, it is recommended to use the inside one, although it is more expensive, the simple working principle and easier maintenance making it unlikely to hire experts only for dealing with the sensor nodes.