Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Modeling Wing Tank Flammability PDF full book. Access full book title Modeling Wing Tank Flammability by Dhaval D. Dadia. Download full books in PDF and EPUB format.
Author: Dhaval D. Dadia Publisher: ISBN: Category : Airplanes Languages : en Pages : 101
Book Description
An investigation into the fire safety of a wing fuel tank has been performed to aid in the effort to eliminate or reduce the possibility of a wing fuel tank explosion in a commercial aircraft. A computational model is built to predict the generation of flammable mixtures in the ullage of wing fuel tanks. The model predicts the flammability evolution within the tank based on in-flight conditions of a wing fuel tank. The model is validated through supporting experiments performed in an altitude chamber, the wind tunnel facility as well as data obtained from flight tests. The results from the experiments are compared to the computational results. Computational results from the altitude chamber follow the general trend of the experimental results, but produce them at a different flash point. This is due to the replenishment of species with lower flash point at the surface of the fuel which emulates the flash point of the entire fuel to be lower. Experimental results for the aluminum wing tests from the wind tunnel experiments are in good agreement with the computational results as well. A simpler model is developed from a program that calculates fuel air ratio within the ullage of fuel tanks in order to reduce the required number of inputs to the model. This model is applied to the data sets for the experiments performed in the altitude chamber and wind tunnel. For the tests conducted in the altitude chamber, the correlation estimates the hydrocarbon concentrations extremely well during ascent and descent. During the on-ground condition the estimation is good, but not as accurate as the ascent or descent conditions. For the tests conducted in the wind tunnel, the computational values follow the general trend of the experimental values, but the computational values estimates the total hydrocarbon concentration approximately 10% lower than the experimental value consistently. Flammability studies are also performed in order to track the effects of temperature, pressure, and oxygen concentration on the upper and lower flammability limits. For the temperature and pressure profiles considered in this work, it is found that the temperature and pressure effects on the flammability limits are minimal. In contrast, the oxygen concentration has a significant effect on the flammability limits of the vapor; the flammable region narrows with a decrease in oxygen concentration.
Author: Dhaval D. Dadia Publisher: ISBN: Category : Airplanes Languages : en Pages : 101
Book Description
An investigation into the fire safety of a wing fuel tank has been performed to aid in the effort to eliminate or reduce the possibility of a wing fuel tank explosion in a commercial aircraft. A computational model is built to predict the generation of flammable mixtures in the ullage of wing fuel tanks. The model predicts the flammability evolution within the tank based on in-flight conditions of a wing fuel tank. The model is validated through supporting experiments performed in an altitude chamber, the wind tunnel facility as well as data obtained from flight tests. The results from the experiments are compared to the computational results. Computational results from the altitude chamber follow the general trend of the experimental results, but produce them at a different flash point. This is due to the replenishment of species with lower flash point at the surface of the fuel which emulates the flash point of the entire fuel to be lower. Experimental results for the aluminum wing tests from the wind tunnel experiments are in good agreement with the computational results as well. A simpler model is developed from a program that calculates fuel air ratio within the ullage of fuel tanks in order to reduce the required number of inputs to the model. This model is applied to the data sets for the experiments performed in the altitude chamber and wind tunnel. For the tests conducted in the altitude chamber, the correlation estimates the hydrocarbon concentrations extremely well during ascent and descent. During the on-ground condition the estimation is good, but not as accurate as the ascent or descent conditions. For the tests conducted in the wind tunnel, the computational values follow the general trend of the experimental values, but the computational values estimates the total hydrocarbon concentration approximately 10% lower than the experimental value consistently. Flammability studies are also performed in order to track the effects of temperature, pressure, and oxygen concentration on the upper and lower flammability limits. For the temperature and pressure profiles considered in this work, it is found that the temperature and pressure effects on the flammability limits are minimal. In contrast, the oxygen concentration has a significant effect on the flammability limits of the vapor; the flammable region narrows with a decrease in oxygen concentration.
Author: William M. Cavage Publisher: ISBN: Category : Airplanes Languages : en Pages : 0
Book Description
"The Fire Safety Team of the Airport and Aircraft Safety Research and Development Division performed tests at the Federal Aviation Administration (FAA) William J. Hughes Technical Center using the environmental chamber and the air induction facility (wind tunnel) to examine individual effects that contribute to commercial transport wing fuel tank flammability. Additionally, previously acquired wing tank flammability measurements taken during flight tests were compared with the results from the FAA Fuel Air Ratio Calculator in an effort to see if the calculations agreed with existing flight test data. The results of the scale fuel tank testing in the environmental chamber showed that (1) fuel height in the tank had little or no effect on the flammability, (2) increasing the amount of heat on the top surface and a higher ambient temperature caused increased flammability, and (3) lower fuel flash point increased flammability greatly. Wind tunnel tests conducted with a section of a Boeing 727 wing tank showed that, under dynamic airflow conditions, change in ullage temperature was the primary mechanism affecting ullage flammability, not fuel temperature, as observed in environmental chamber tests. Other wind tunnel tests showed that the angle of attack of the fuel tank played little role in reducing fuel tank flammability, but that a cross-venting condition of the fuel tank would lead to a very rapid decrease in hydrocarbon concentration. An input temperature algorithm could be used with the FAA Fuel Air Ratio Calculator to significantly improve predictions of wing tank ullage flammability, based on tests that showed in-flight changes of ullage flammability in a wing tank are driven largely by the ullage temperature. This is very different from what had been shown with a center wing fuel tank, in which fuel temperature continues to be the main driver of flammability even during flight."--Report documentation page
Author: AE-5D Fuel Tank Flammability Reduction Systems Committee Publisher: ISBN: Category : Languages : en Pages : 0
Book Description
The Aerospace Recommended Practices of this document are intended for nitrogen-based Flammability Reduction Means (FRM) implemented on transport category, turbine powered airplanes. The recommended practices herein, therefore, relate only to the transport category aircraft, and focus specifically on contemporary inerting systems equipment. Such systems are referred to a Fuel Tank Inerting Systems (FTIS) in this document. This document does not cover the following: Military aircraft applications Air separation technologies other than hollow fiber membrane (HFM) and pressure swing adsorption (PSA) Inerting of conventional unheated wing tanks or aircraft dry bays Expected future technology solutions for the generation of inert gas.The advice contained in this document is aimed towards providing aircraft manufacturers with guidance on the key issues associated with contemporary aircraft fuel tank inerting systems to supplement the guidance in FAA Advisory Circular AC 25.981-2. This document also provides system and component designers and manufacturers with advice on what aspects must be evaluated and addressed when designing a safe, low risk solution for transport aircraft fuel tank Flammability Reduction Means. As such, the information herein is intended as a guide for some system design aspects, but primarily identifies the issues which must be addressed in designing an inerting system for fuel tank flammability reduction. This document provides recommended practices for developing a non-aircraft specific commercially certifiable nitrogen based Flammability Reduction Means (FRM) including the applicable design considerations supporting Title 14 Code of Federal Regulations part 25, Appendix M, for Transport Category Airplanes" (Reference 14 CFR 25.981).
Author: P. M. McConnell Publisher: ISBN: Category : Airplanes Languages : en Pages : 116
Book Description
The low temperature performance of antimisting kerosene (AMK) in airframe fuel systems and in certain fuel system components was studied and compared to Jet A fuel. Water vapor ingested into fuel tanks during simulation of repeated descents through clouds and rain had little effect on AMK. AMK retained antimisting properties during exposure to severe environmental flight simulations. Jet pump and boost pump operation had no discernable effect on AMK flammability. Jet pump performance with AMK was adversely affected. Main fuel boost pumps required up to 18 percent more power with AMK that with Jet A, and suction feed performance was lower with ambient and -20 deg C, but better than Jet A and -40 deg C. Boost pump performance was not affected by gel formations produced at low temperatures by the vapor removal return flow shearing of AMK. Aerodynamic heating and cooling of AMK in the fuel tank was similar to Jet A.A high pressure pump and needle valve used to degrade the AMK was inadequate, resulting in filter bypass at low temperatures. (Author).
Author: Publisher: ISBN: Category : Languages : en Pages : 58
Book Description
This study assessed differences in headspace flammability for summertime gasolines and new high-ethanol content fuel blends. The results apply to vehicle fuel tanks and underground storage tanks. Ambient temperature and fuel formulation effects on headspace vapor flammability of ethanol/gasoline blends were evaluated. Depending on the degree of tank filling, fuel type, and ambient temperature, fuel vapors in a tank can be flammable or non-flammable. Pure gasoline vapors in tanks generally are too rich to be flammable unless ambient temperatures are extremely low. High percentages of ethanol blended with gasoline can be less volatile than pure gasoline and can produce flammable headspace vapors at common ambient temperatures. The study supports refinements of fuel ethanol volatility specifications and shows potential consequences of using noncompliant fuels. E85 is flammable at low temperatures; denatured ethanol is flammable at warmer temperatures. If both are stored at the same location, one or both of the tanks' headspace vapors will be flammable over a wide range of ambient temperatures. This is relevant to allowing consumers to splash -blend ethanol and gasoline at fueling stations. Fuels compliant with ASTM volatility specifications are relatively safe, but the E85 samples tested indicate that some ethanol fuels may produce flammable vapors.
Author: Publisher: ISBN: Category : Languages : en Pages : 41
Book Description
Study to measure the flammability of gasoline/ethanol fuel vapors at low ambient temperatures and develop a mathematical model to predict temperatures at which flammable vapors were likely to form.
Author: Adam Paul Harris Publisher: ISBN: Category : Languages : en Pages :
Book Description
Managing the effects of dissolved air evolution from aviation fuel has presented long-standing issues for the design and operation of aircraft fuel systems. This phenomenon, known colloquially as fuel outgassing, is responsible for a broad spectrum of fuel system issues, including; increased fuel tank flammability, two-phase flow in pipes, fuel pump cavitation and fuel tank over- pressurisation. The rate and effects of oxygen evolution from Jet A-I aviation turbine fuel is studied here using experimental techniques, dimensional modelling and aircraft flight testing. The rate of fuel agitation present within a laboratory fuel tank was demonstrated to have the greatest effect on the rate of oxygen evolution from the fuel. Oxygen evolution rate increased hyperbolic ally with increasing fuel agitation rate under pressure and temperature conditions consistent with an aircraft fuel tank during flight. Dimensional modelling was used to estimate the rate of oxygen evolution in an Airbus A320-200 aircraft fuel tank from measurements made on a dimensionally similar laboratory model. The extrapolated rate of oxygen evolution from similarity laws was found to be over 200% greater in the A320 inner wing fuel tank than that measured in the laboratory model. Further work is required to validate the similarity laws of fuel outgassing with flight test data if dimensional modelling is to be adopted for estimating fuel outgassing rates in aircraft fuel tank flammability studies. Flight testing on an Airbus A340-300 aircraft revealed the effect of fuel outgassing on a nitrogen inerted Centre Wing Fuel Tank (CWT) ullage to be minimal. CWT ullage oxygen concentration increased primarily due to atmospheric air inspired via the vent system, resulting from a reducing fuel quantity in the CWT. This unexpected result is believed to have been influenced by a combination of the fuel's tendency to absorb nitrogen from the ullage during CWT refuel, a large ullage to fuel ratio and near quiescent CWT fuel conditions.
Author: D. P. Gardiner Publisher: ISBN: Category : Ethanol as fuel Languages : en Pages : 32
Book Description
An experimental study measured the flammability of fuel vapors at low ambient temperatures and developed a mathematical model to predict the temperatures at which flammable vapors were likely to form. Results indicate that some currently available ethanol fuels are likely to produce flammable vapors within the ambient temperature range under Class 3 conditions. Results also indicate that mid-level ethanol blends (E20 and E30) are unlikely to significantly increase the risk of producing flammable vapors over that of the base gasoline used for the blends.
Author: Dhaval D. Dadia
Author: Dhaval D. Dadia
Author: William M. Cavage
Author: Steven M. Summer
Author: AE-5D Fuel Tank Flammability Reduction Systems Committee
Author: 
Author: P. M. McConnell
Author: 
Author: 
Author: Adam Paul Harris
Author: D. P. Gardiner