scholarly journals Dimensional modelling of the fuel outgassing phenomenon: Improving flammability assessment of aircraft fuel tanks

2011 ◽  
Vol 115 (1172) ◽  
pp. 605-614 ◽  
Author(s):  
A. P. Harris ◽  
N. M. Ratcliffe
Keyword(s):  
Oxygen Evolution ◽  
Oxygen Transfer Rate ◽  
Fuel Tank ◽  
Aviation Fuel ◽  
Evolution Rate ◽  
Time Constants ◽  
Oxygen Evolution Rate ◽  
Aircraft Fuel ◽  
Wide Range ◽  
Fuel Tanks

Abstract Fuel outgassing (oxygen evolution) within aircraft fuel tanks presents a serious flammability hazard. Time constants representing oxygen transfer rate, from the fuel into a tank’s ullage, are used to model the effect of outgassing on tank flammability. These time constants are specific to a single aircraft type and flight envelope and may not accurately represent fuel outgassing behaviour for other aircraft types with differing fuel tank configurations and flight envelopes. To improve current modelling practice for more accurate flammability analysis dimensional modelling has been used to determine the rate of oxygen evolution from Jet A-1 fuel in an aircraft fuel tank. Measurements of oxygen evolution rate, made on a dimensionally similar model, have been projected to an A320 aircraft. The evolution of oxygen from the fuel was found to increase monotonically with time. Fitting the test data with an inverse-exponential function enabled oxygen release rate and its associated time constant (τ) to be determined. Dimensional modelling of aviation fuel outgassing using model fuel tanks will enable oxygen evolution rate from aviation fuel to be determined for a wide range of aircraft fuel tank configurations and environments without the need for flight testing. In turn the accuracy of flammability assessment of aircraft fuel tanks will be improved and significant cost savings made.

Oxygen evolution rate of rice cultivars

2008 ◽  
Vol 46 (1) ◽  
pp. 148-150 ◽  
Author(s):  
M. A. Bacarin ◽  
A. R. Falqueto ◽  
J. L. Coimbra ◽  
A. C. Oliveira ◽  
A. M. De Magalhaes
Keyword(s):  
Oxygen Evolution ◽  
Evolution Rate ◽  
Rice Cultivars ◽  
Oxygen Evolution Rate

scholarly journals Analytical Algorithm for Oxygen Concentration of Aircraft Fuel Tank in Various Inerting Stages

2021 ◽  
Vol 11 (16) ◽  
pp. 7698
Author(s):  
Yuhao Wei ◽  
Yang Pei ◽  
Yuxue Ge
Keyword(s):  
Differential Equations ◽  
Oxygen Concentration ◽  
Fuel Tank ◽  
Conventional Model ◽  
Aircraft Fuel ◽  
Proposed Model ◽  
Fuel Tanks ◽  
Analytical Algorithm ◽  
Fire And Explosion ◽  
Derivatives Of

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.

Elementary Computer Modeling Applied to TWA800 Fuel Tank Forensic Issues

1998 ◽  
Author(s):  
Floyd A. Wyczalek
Keyword(s):  
Jet Fuel ◽  
Combustible Mixture ◽  
Scientific Data ◽  
Fuel Tank ◽  
Critical Conditions ◽  
Jet Fuels ◽  
Potential Hazard ◽  
Minimum Ignition Energy ◽  
Aircraft Fuel ◽  
Fuel Tanks

Abstract The specific mission was to identify the conditions of atmospheric pressure and ambient temperature under which a so-called empty-Boeing model 747-131 fixed wing jet aircraft center wing tank (CWT), containing a residual fuel loading of about 3 kg/m3, less than 100 gallons of aviation kerosene (JetA Athens refinery commercial jet fuel), could form hazardous air/fuel mixtures. The issues are limited to explosion safety concerns relating to certificated fixed wing jet aircraft in regularly scheduled commercial passenger service. It is certain that a combustible mixture does not exist in a fuel tank containing Jet-A type fuel at ambient temperatures below 38°C (100°F), which is the lean limit flash point (LFP) for commercial jet fuel at sea level. Never the less, although not included in this paper, the original study reported by Wyczalek and Suh (1997), identified six highly unlikely, but rationally possible critical conditions which can occur in a combination which may permit a combustible mixture to exist within a jet aircraft fuel tank and pose a potential hazard. The scope of this paper is limited to mathematical modeling concerns related to fixed wing jet aircraft fuel tanks and commercial jet fuels combustible air-fuel mixture ratios. It was further limited to a historical review of the scientific literature in the public domain from 1950 to the present time, which defined the thermodynamic and minimum ignition energy properties of aviation gasoline and commercial jet fuels; and, to comparisons with new thermodynamic data for JetA Athens flight test samples, released by the National Transportation Safety Board (NTSB) during public hearings on the TWA800 event in Baltimore, Maryland in December 1997. The original work reported by Wyczalek and Suh (1997) conclusively demonstrated that the USAF Wright Air Development Center and the US Bureau of Mines conducted and published comprehensive evaluations of the potential hazards relating to jet aircraft fuel tanks as early as 1952. This historical scientific data and the mathematical models for the new jetA and Athens refinery jetA in this paper, are relevant to pending TWA800 related litigation, and to the future implementation of NTSB recommendations resulting from the TWA800 event.

Studies on the Protection of Aircraft Oil Tank’s Microbic Erosion Based on Properties of Machinery and Biological Materials

2015 ◽  
Vol 730 ◽  
pp. 245-248
Author(s):  
Zheng Wei ◽  
Fang Chao Wang ◽  
Yuan Sheng Wang ◽  
Hong Wei Yu
Keyword(s):  
Quaternary Ammonium ◽  
Microbial Growth ◽  
Microbiologically Influenced Corrosion ◽  
Aviation Fuel ◽  
Fuel System ◽  
Microbiological Corrosion ◽  
Microbial Corrosion ◽  
Aircraft Fuel ◽  
Fuel Tanks ◽  
Growth And Reproduction

Microbiological corrosion to the aircraft fuel system caused by microbial growth and reproduction in aviation fuel may also lead a serious safety risk to aircraft. Categories of microorganism in aircraft fuel tanks,reasons and protection methods of microbial corrosion were summarized and the research of microbiologically influenced corrosion protection which connected with quaternary ammonium germicides was prospected in this paper.

Tuning Hole Accumulation of Metal Oxides Promotes the Oxygen Evolution Rate

ACS Catalysis ◽  
2020 ◽  
Vol 10 (18) ◽  
pp. 10427-10435
Author(s):  
Peikun Zhang ◽  
Wei Wang ◽  
Hui Wang ◽  
Yanbo Li ◽  
Chunhua Cui
Keyword(s):  
Metal Oxides ◽  
Oxygen Evolution ◽  
Evolution Rate ◽  
Oxygen Evolution Rate

A survey of microbial contamination in aviation fuel from aircraft fuel tanks

2019 ◽  
Vol 65 (2) ◽  
pp. 371-380
Author(s):  
Dong Hu ◽  
Jie Zeng ◽  
Shangshu Wu ◽  
Xi Li ◽  
Chengsong Ye ◽  
...  
Keyword(s):  
Microbial Contamination ◽  
Aviation Fuel ◽  
Aircraft Fuel ◽  
Fuel Tanks

Oxygen evolution rate in Antarctic filamentous alga Stigeoclonium sp. evaluated by optodes relates to chlorophyll fluorescence parameters (Short Communication)

2018 ◽  
Vol 8 (1) ◽  
pp. 143-150
Author(s):  
Peter Váczi
Keyword(s):  
Chlorophyll Fluorescence ◽  
Linear Relationship ◽  
Oxygen Evolution ◽  
Photosynthetically Active Radiation ◽  
Filamentous Alga ◽  
Evolution Rate ◽  
O2 Evolution ◽  
Effective Quantum Yield ◽  
Active Radiation ◽  
Oxygen Evolution Rate

Photosynthetic reactions of algal communities, the essential component of primary production in polar regions, are strongly dependent on environmental factors. Among them, availability and amount of light in particular parts of growing season are of major importance. In this paper, the response of the photosynthetic processes of a filamentous fresh-water alga to photosynthetically active radiation (PAR) was studied by two approaches. The simultaneous measurements of the effective quantum yield (FPSII) and oxygen evolution rate (OER) at stepwise increasing photosynthetically active radiation provided data for beneficial correlation analysis of the FPSII to OER relationship in a wide range of PAR. In this study, the culture of filamentous alga Stigeoclonium sp. was analyzed. The linear relationship between FPSII and OER was found for the low PAR (the range of 0 – 200 mmol.m-2.s-1). At high PAR levels (200 – 1000 mmol.m-2.s-1) another linear relationship with different slope was found. The approach combining the fluorometric and oxymetric method might be used for calibration of data in follow up studies and, consequently for evaluation of photosynthetic rates (O2 evolution) from chlorophyll fluorescence data.

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