Browse Topic: Jet fuel

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Aircraft and Aircraft Engine Fuel Pump Low Lubricity Fluid Endurance TestARP1797B (Current)11/26/2025
This procedure is intended to apply to fuel pumps. This procedure will be defined in terms of recommended test fluid, test setup, test conditions, and test method. This procedure may be used for other fuel system components, by testing in conjunction with the pump, which normally supplies the component inlet flow, or a substitute test pump of similar capacity. This procedure may be used, with variations in test conditions and test fluid for performing pump evaluation tests. Tests at progressively increasing pump speeds and pressures will provide design limitation data. Alternate test periods on a test pump and another pump, of a design for which actual service durability is known, will provide useful comparison data.
AE-5B Aircraft and Engine Fuel and Lubricant Sys Components
Aviation Lubricant Tribology Evaluator (ALTE) Method to Determine the Lubricating Quality of Gas Turbine LubricantsARP6255A (Current)11/26/2025
Employing ‘ball-on-cylinder’ philosophy, a non-rotating steel ball is held in a vertically mounted chuck and using an applied load is forced against an axially mounted steel cylinder. The test cylinder is rotated at a fixed speed while being partially immersed in a lubricant reservoir. This maintains the cylinder in a wet condition and continuously transports a lubricating film of test fluid to the ball and cylinder interface. The diameter of the wear scar generated on the test ball is used as a measure of the fluid’s lubricating properties. The apparatus can be used, by adjusting the operating conditions, to reproduce two different wear mechanisms; mild and severe wear, the ALTE therefore has the ability to assess a lubricant’s performance in that regard.
E-34 Propulsion Lubricants Committee
DRYING OF THERMOSETTING COMPOSITE MATERIALSARP4977 (Current)5/14/2021
This SAE Aerospace Recommended Practice (ARP) describes standard methods for drying commercial aircraft composite structures prior to repair and gives general guidelines on use and applicability. It addresses the removal of liquids that have collected inside the structures through open damage, microcracks, or porosity and the removal of absorbed moisture from the composite material. The methods described in this document shall only be used when specified in an approved repair document or with the agreement of the original equipment manufacturer (OEM) or regulatory authority. If this document is used for the drying of materials other than thermosetting composite materials, the fitness for this purpose must be determined by the user.
AMS CACRC Commercial Aircraft Composite Repair Committee
Connectors, Fiber Optic, Advanced, Circular or Rectangular, Plug and Receptacle, Environment Resistant, Removable Termini/Contacts, General Specification ForAS5590B (Current)11/30/2020
This specification covers the performance requirements for a plug and receptacle. The connector inserts may contain multiple termini or multiple termini and electrical contacts. The connectors use removable termini, or removable termini and electrical contacts, and are capable of operating within a temperature range of −65 to +200 °C (see 1.2.1.1). These connectors are supplied under AS9100 reliability assurance program.
AS-3 Fiber Optics and Applied Photonics Committee
Vehicle, Magnetic Particle Inspection Petroleum BaseAMS2641D (Current)10/9/2020
This specification covers two types of refined hydrocarbon compounds in the form of liquids. This specification only covers newly manufactured materials.
AMS K Non Destructive Methods and Processes Committee
Fluid, Jet ReferenceAMS2629F (Current)3/12/2020
This specification covers a mixture of liquid hydrocarbons and soluble additives.
AMS G9 Aerospace Sealing Committee
Green Jet Fuel Additive Made from Acetone Plus LightTBMG-361733/1/2020
A domestically generated additive was made by taking biomass-derived acetone — common nail polish remover — and using light to upgrade it to higher-mass hydrocarbons. It can be blended with conventional jet fuel to fly while providing environmental benefits.
Engineered Solutions for Enclosure Sealing and InsulationTBMG-3566812/1/2019
In the aerospace and defense industries, enclosure sealing and insulation needs to meet challenging and complex requirements. For example, the EMI gaskets that are used in military touchscreens must shield sensitive electronics from electromagnetic interference (EMI) while providing electrical conductivity and ensuring environmental sealing. These enclosure gaskets must also cushion the unit from mechanical shock and avoid interfering with the display's touch function.
Low- to High-Temperature Reaction Transition in a Small-Bore Optical Gasoline Compression Ignition (GCI) Engine03-12-05-00318/19/2019
Abstract This study shows the development of low-temperature and high-temperature reactions in a gasoline-fuelled compression ignition (GCI) engine realizing partially premixed combustion for high efficiency and low emissions. The focus is how the ignition occurs during the low- to high-temperature reaction transition and how it varies due to single- and double-injection strategies. In an optically accessible, single-cylinder small-bore diesel engine equipped with a common-rail fuel injection system, planar laser-induced fluorescence (PLIF) imaging of formaldehyde (HCHO-PLIF), hydroxyl (OH-PLIF), and fuel (fuel-PLIF) has been performed. This was complemented with high-speed imaging of combustion luminosity and chemiluminescence imaging of cool flame and OH*. The diagnostics were performed for two different fuels including conventional diesel as a reference case and then a kerosene-based jet fuel which is a low-ignition quality fuel with cetane number of 30, firstly with single near top dead center (TDC) injection and then a double-injection strategy implementing very early injection and late injection in the same engine. For diesel combustion, it is shown that the cool-flame and HCHO signals appear from the jet axis before spreading downstream towards the bowl wall. The OH radicals present in the high-temperature reaction zones also show a similar development pattern with distinctive reaction zones forming from the jet axis and then near the bowl wall for each nozzle hole. When the reactions occur near the bowl wall, the HCHO and OH radicals coexist. Later, the high-reaction zones merge with each other due to jet-wall and jet-jet interactions. In comparison, the single-injection GCI combustion shows HCHO signals appearing from the bowl-wall region due to extended ignition delay. The OH radicals develop out of this HCHO region and show a more sequential development pattern than diesel combustion. The single-injection GCI also involves multiple ignition kernels that progressively merge to form larger reaction zones. The double-injection GCI combustion has higher charge premixing than the other cases, and due to very early first injection, the mixture homogeneity is also much higher. This is evidenced by a higher consumption rate of HCHO and faster development of OH across the entire reaction zones, indicating faster low- to high-temperature reaction transition. These fundamental findings explain why GCI combustion generates less soot and NO than diesel combustion as well as how double-injection GCI combustion achieves better low-load stability than the single-injection.
Goyal, Harsh, Zhang, Yilong, Kook, Sanghoon, Kim, Kenneth S., Kweon, Chol-Bum
Identification and Quantification of Phosphate Ester-Based Hydraulic Fluid in Jet Fuel04-12-01-00033/13/2019
Phosphate ester-based hydraulic fluids are commonly used in aviation, due to their fire-resistant properties. However, contamination of jet fuel with hydraulic fluid may cause serious engine failure, hot corrosion of metals, and swelling of elastomer and polymer seals. Identifying and quantifying hydraulic fluids in jet fuels using chromatography is challenging since common hydraulic fluids, such as ExxonMobil™ HyJet™ V and Skydrol™ LD-4, are composed of tri-butyl phosphate, the main peak of which overlaps with peaks from jet fuels in chromatograms. In this work, three techniques to separate and differentiate the jet fuel peaks from the tri-butyl phosphate peaks were developed. Two methods are based on a solid phase extraction (SPE) procedure followed by identification and quantification, which is carried out using a gas chromatograph equipped with a mass spectrometer or a flame ionization detector. The third technique is single-staged, where the separation and analysis are carried out by a gas chromatograph equipped with a polar column and a mass spectrometer. Lowest level of detection reached was 0.1 ppm of tri-butyl phosphate in jet fuel, 10 times lower than the limitations. Linearity was achieved in all analysis methods up to contamination of 100 ppm.
Stamker Gertopski, Diana, Tartakovsky, Konstantin, Rabaev, Moshe
Sleeve, Hose Assembly, Fire ProtectionAS1072F (Current)1/7/2019
This standard defines the requirements for bulk protective sleeve to provide fire resistance for aircraft hose assemblies, which will enable these assemblies to meet the requirements of AS1055. NOTE: Use of this sleeve does not eliminate the need to demonstrate that the sleeved assemblies will meet the applicable requirements of AS1055.
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
Novel Turboelectric Aircraft DesignTBMG-288615/1/2018
NASA Langley Research Center has developed a novel aircraft design that can carry 150+ passengers over a range of 3,500 nautical miles. Key features include a turboelectric propulsion system, twin underwing turbofans, and a rear-fuselage, electrically driven, boundary layer ingesting fan. The design is developed for single-aisle-class aircraft (the largest commercial transport class in the world) to significantly reduce fuel burn compared to current aircraft.
The Application of New Approaches to the Analysis of Deposits from the Jet Fuel Thermal Oxidation Tester (JFTOT)2017-01-229310/8/2017
Studies of diesel system deposits continue to be the subject of interest and publications worldwide. The introduction of high pressure common rail systems resulting in high fuel temperatures in the system with the concomitant use of fuels of varying solubilizing ability (e.g. ULSD and FAME blends) have seen deposits formed at the tip of the injector and on various internal injector components. Though deposit control additives (DCAs) have been successfully deployed to mitigate the deposit formation, work is still required to understand the nature and composition of these deposits. The study of both tip and internal diesel injector deposits (IDID) has seen the development of a number of bench techniques in an attempt to mimic field injector deposits in the laboratory. One of the most used of these is the Jet Fuel Thermal Oxidation Tester or JFTOT (ASTM D3241). The tester was originally designed to assess the oxidation of jet fuel, based on the principle that low stability fuels produce deposits that form on metal surfaces. Recently it has been modified so that under suitable conditions it may be used to determine the deposit forming potential of diesel fuels. The JFTOT technique has been used by a number of groups to try and understand diesel injector deposits. The ineradicable nature of the material on the JFTOT tube has seen the deposits analyzed by laser scanning microscopy, ellipsometry and recently infra-red microscopy. Other methods have been invasive involving either solvent washing or scraping off the deposit. In this paper other techniques for the analysis of deposits will be described yielding both chemical and metrological characteristics of the deposits. Fourier Transform Infrared Microscopy (FTIRM), and Time-of- Flight Secondary Ion Mass Spectrometry (ToFSIMS) will be used to describe the surface characteristics. Measurements from a Profile meter will be used to estimate deposit surface roughness and data from Scanning Electron Microscopy (SEM) will be employed to describe the morphology. The final techniques described will be Direct Analysis In Real Time Mass Spectrometry (DARTMS) using ambient mass spectrometry. and Fourier Transform Ion Cyclotron Resonance Mass spectrometry (FTICRMS) The advantage of the DART method is that mixtures and objects can be subjected to mass spectrometric analysis with the minimum of pre-treatment and sample preparation. Thus the technique is well suited for analyzing deposits on JFTOT tubes as it requires little sample preparation. A number of studies of materials deposited on JFTOT tubes will be described showing the suitability of these techniques for analyzing and providing the potential characterization of JFTOT deposits. The FTICRMS will be used to assign species in the JFTOT test fuels both pre and post test.
Barker, Jim, Reid, Jacqueline, Angel Smith, Sarah, Snape, Colin, Scurr, David, Langley, Graham, Patel, Krina, Carter, Anastarsia, Lapthorn, Cris, Pullen, Frank
Kilohertz Mie Scattering and OH* Chemiluminescence Imaging of JP-8 Multiple Injections Using a 250 MPa Fuel Injector2017-01-08323/28/2017
The objective of the study was to investigate the spray and combustion characteristics of Jet Propellant-8 (JP-8) using a high-pressure fuel injector which is capable of up to 250-MPa fuel injection pressure. Experiments were performed in a constant-pressure flow-through combustion chamber at the ambient conditions of 825 K and 6 MPa for the oxygen concentration of 0 and 21%. JP-8 was injected over a range of fuel injection pressures from 50 to 250 MPa for single injection events to establish a baseline operation. Pilot and post injections were used to study the effect of multiple injections on spray and combustion of the high-pressure fuel injector. Both pilot and post injection separation times and quantities were systematically varied. JP-8 spray and combustion events were imaged at 75 kHz using a combination of Mie scattering and OH* chemiluminescence imaging. The Mie scattering results showed that spray atomization and mixing was enhanced with increasing fuel injection pressure which was indicated as thinner and more uniform liquid columns. For non-reacting multiple injections, both pilot and post injections showed shorter liquid penetration lengths which were due to incomplete needle lift for these small injection quantities. Liquid penetration length of the main injection was slightly decreased as the pilot separation time was shortened. At higher fuel injection pressure, the main injection showed decreased hydraulic delay at the shortest pilot separation time. Furthermore, liquid penetration length of the post injection decreased at higher fuel injection pressure. Spray patterns became more uniform both within an injection and across injection events at the higher fuel pressures. Ignition delay decreased almost linearly with increasing fuel injection pressure. The OH* intensity showed that pilot injection led to more uniform main combustion which may result in improved combustion stability. Ignition delay increased at higher fuel injection pressure for the double injection events due to leaner mixtures with faster combustion at higher fuel pressure. Higher fuel injection pressure retarded the post combustion and post combustion became insensitive to the post separation time.
Temme, Jacob, Coburn, Vincent, Kweon, Chol-Bum
Fluid, Jet ReferenceAMS2629E (Historical)2/8/2017
This specification covers a mixture of liquid hydrocarbons and soluble additives.
AMS G9 Aerospace Sealing Committee
Energy Storage for Commercial Hybrid Electric Aircraft2016-01-20149/20/2016
Energy storage options for a hybrid electric commercial single aisle aircraft were investigated. The propulsion system features twin Geared Turbofan™ engines in which each low speed spool is assisted by a 2,500 HP electric motor during takeoff and climb. During cruise, the aircraft is powered solely by the turbine engines which are sized for efficient operation during this mission phase. A survey of state of the art energy storage options was conducted. Battery, super-capacitor, and flywheel metrics were collected from the literature including Specific Energy (Wh/kg), Volumetric Energy Density (Wh/L), Specific Power (W/kg), Cost ($/kWh), and Number of Cycles. Energy storage in fuels was also considered along with various converters sized to produce a targeted quantity of electric power. The fuel and converters include fuel cells (both proton exchange membrane and solid oxide operating on hydrogen or on jet fuel) and a turbogenerator (jet fuel or LNG). The various energy storage options were compared across a range of stored energy on the basis of weight. The selection of a lightweight energy storage technology depends on power and quantity of energy storage. A turbogenerator auxiliary power unit has the best energy and power density for the application. The fuel cells tend to be heavy options due to low specific power. PEM fuel cells operating on compressed or liquid hydrogen are lighter weight than SOFCs, however, PEMFCs are comparable to batteries at the energy storage design point of 1500 kWh. Applications requiring low detectability and long duration favor PEM fuel cells.
Rheaume, Jonathan M., Lents, Charles
Ball-On-Cylinder (BOC) Aircraft Turbine Fuel Lubricity TesterAIR1794A (Historical)5/13/2016
This metric SAE Aerospace Information Report (AIR) details a ball-on-cylinder (BOC) test device and specifies a method of rating the relative lubricity of aviation turbine fuel samples. The BOC produces a wear scar on a stationary steel ball by forcing it with a fixed load against a fuel wetted steel test ring in a controlled atmosphere. The test ring is rotated at a fixed speed so its surface is wetted by a momentary exposure to the fluid under test. The size of the wear scar is a measure of the test fluid lubricity and provides a basis for predicting friction or wear problems.
AE-5B Aircraft and Engine Fuel and Lubricant Sys Components
Spray Characterization and Ignition Delay Measurements of JP-8 and IPK in a Constant-Pressure Flow Chamber2016-01-07364/5/2016
This research compares the spray development and combustion characteristics of jet propellant 8 (JP-8) and iso-paraffinic kerosene (IPK) through a range of diesel engine in-cylinder operating conditions. Non-reacting spray experiments were performed in a constant-pressure flow chamber with 99% nitrogen gas composition at constant temperature (900 K) and densities ranging from 11-56 kg/m3. Near-simultaneous, high-speed Mie and schlieren images of the spray were acquired to measure the liquid and vapor penetration lengths of the non-reacting jet. Reacting experiments, consisting of photodiode measurements and intensified high-speed movies of OH* chemiluminescence, were performed at the same thermodynamic conditions as the non-reacting experiments, except with a 21%/79% oxygen/nitrogen ambient gas composition. Measurements of the rate of injection, issued from a single-hole axial common-rail fuel injector, showed negligible differences between the fuels. The non-reacting liquid length of IPK was approximately 20% shorter than JP-8 for the range of tested conditions, which was consistent with the average difference in volatility between the fuels. The ignition delay, determined from the photodiode record, was up to 80% longer for IPK fuel at low density conditions. Additionally, the lift-off length of IPK was measured to be approximately 50% more sensitive to ambient pressure than JP-8. These results provide fundamental information for the calibration and optimization of military diesel engines operating on conventional and alternatively sourced jet fuels.
Tess, Michael, Kurman, Matthew, Kweon, Chol-Bum
A Technical Evaluation of New Renewable Jet and Diesel Fuels Operated in Neat Form in Multiple Diesel Engines2016-01-08294/5/2016
The US Navy is in the process of evaluating Catalytic Hydrothermal Conversion Jet fuel (CHCJ-5) for inclusion in the JP-5 specification, MIL-DTL-5624, and evaluating Catalytic Hydrothermal Conversion Diesel fuel (CHCD-76) for inclusion in the F-76 specification, MILDTL-16884. CHC fuels are produced from renewable feedstocks such as triglycerides, plant oils, and fatty acids. A Catalytic Hydrothermolysis process chemically converts these feedstocks into a mixture of paraffins, cycloparaffins, aromatics, olefins, and organic acids. The resulting mixture is then hydroprocessed and fractionated to produce a kerosene (or diesel) product having a distillation profile comparable to traditional petroleum derived fuels. The end product is a fuel that is able to meet the jet (or diesel) chemical and physical MIL-SPEC requirements without blending with conventional petroleum fuels. Detailed physical and chemical characterizations are presented showing these new renewable fuels in neat form have similar properties as compared to their natural petroleum counterparts (JP-5 and F-76). Engine testing was performed using three highly instrumented engines (Waukesha, Yanmar and AM General). CHCJ-5 was compared to the combustion performance of JP-5, while CHCD-76 was compared to conventional diesel NATO F-76. Engine data from this testing was processed to compare the fuels on the basis of relative combustion metric changes. The results of this testing and analysis show that, in general, ignition delay is similar to or slightly shorter than the base fuel. Combustion phasing shifts are quite small, with the maximum rate of heat release showing a modest decrease with the CHC fuels due to their moderately higher cetane values. Overall, both CHC fuels have combustion changes that fall within Navy acceptance standards. Engine operation (including cold starting) with these new renewable neat fuels was similar to the base natural petroleum fuels with no concerns noted.
McDaniel, Andrew, Dickerson, Terrence, Luning-Prak, Dianne, Hamilton, Len, Cowart, Jim
Fusible-Core PolymerTBMG-2313810/1/2015
Egmond Plastic Alkmaar, The Netherlands +31-72-5614644
Effects of Ice Accretion in an Aircraft Protective Mesh Strainer of a Fuel Pump2015-01-24499/15/2015
This paper focuses on the investigation of the nature, process and effects of ice accretion on different feed pump strainers upstream of the aircraft feeding system. A suitable test rig was designed to circulate Jet A-1 containing water/ice contaminants at cold temperatures through the strainers. Following an extensive literature review, a number of screening tests were performed. These provided a strong base for an exhaustive study of fuel icing in the dynamic environment offered by the test rig. The effects of the rate of fuel cooling on the nature of ice were examined. As expected, it was observed that the yield of ice generated on the mesh screen increased with the water concentration in the fuel. It was also revealed that at higher cooling rates, a crust of snow formed on top of softer ice on the mesh screen. This phenomenon induced a slight drop in pressure across the mesh screen, indicating that the permeability of the crust layer is lower, but still allowed the passage of fuel through its structure. Comparing the particulate contamination experiments with the first set of results of uncontaminated fuel, it was observed that when there are foreign particles suspended in jet fuel, there is a higher yield of ice generated and accreted on the pump strainer
Baena, Solange, Lam, Joseph K-W, Lawson, Craig
Water Solubility in Different Alternative Jet Fuels: A Comparison with Petroleum-Based Jet Fuel2015-01-25639/15/2015
The paper presents an extensive assessment of the hygroscopic characteristics of a number of alternative jet fuel blends. These are blended with conventional Jet A-1 to conform with current aviation standards at a 50:50 ratio by volume, except for DSHC (Direct Sugar to Hydrocarbon), which is blended at 10% DSHC and 90% Jet A-1. Given the lack of information available on the water solubility of alternative jet fuels, an effective analysis of experimental data about this characteristic in six different alternatives was performed. These included four ASTM approved alternatives (two Fischer-Tropsch (FT) synthetics from coal and natural gas, one HEFA (Hydroprocessed Esters and Fatty Acids) derived from camelina and DSHC. An extra two alternatives currently under consideration for ASTM approval were also tested; ReadiJet and an ATJ (Alcohol to Jet). Water solubility-temperature curves were created and compared to the Jet A-1 reported in the CRC (Coordinating Research Council) Handbook of Aviation Fuel Properties. All samples were subjected to a temperature range of −20°C to 50°C, significantly wider than that illustrated in recent studies and the CRC Handbook. The preliminary results suggest that the alternative fuel blends followed a different pattern to the CRC Jet A-1 for water solubility at different temperatures. Unlike the conventional fuels, the curves did not fit an exponential trend. The preliminary results need to be verified to assert confidence in the results with further testing. The results for the water absorption between −20°C and 50°C for each alternative blend were measured and it was found that DSHC:Jet A-1 absorbed the most water, and ReadiJet:Jet A-1 the least. Further work is planned to validate the trends observed.
Charro, Alberto, Baena, Solange, Lam, Joseph K-W
Characterization of the Ultrafine and Black Carbon Emissions from Different Aviation Alternative Fuels2015-01-25629/15/2015
This study reports gaseous and particle (ultrafine and black carbon (BC)) emissions from a turbofan engine core on standard Jet A-1 and three alternative fuels, including 100% hydrothermolysis synthetic kerosene with aromatics (CH-SKA), 50% Hydro-processed Esters and Fatty Acid paraffinic kerosene (HEFA-SPK), and 100% Fischer Tropsch (FT-SPK). Gaseous emissions from this engine for various fuels were similar but significant differences in particle emissions were observed. During the idle condition, it was observed that the non-refractory mass fraction in the emitted particles were higher than during higher engine load condition. This observation is consistent for all test fuels. The 100% CH-SKA fuel was found to have noticeable reductions in BC emissions when compared to Jet A-1 by 28-38% by different BC instruments (and 7% in refractory particle number (PN) emissions) at take-off condition. BC emissions from this fuel were lower than from Jet A-1 by 45-50% (and 25-26% in refractory PN) at idle or cruise condition. The 100% CH-SKA fuel was observed to have a minimum influence on non-refractory PN emissions. A lower volume in naphthalene in the 100% CH-SKA fuel was hypothesized to be one of the factors attributing to the reduced BC emissions when compared to Jet A-1 emissions. For the 50% HEFA-SPK fuel, BC emissions were lower than the BC emissions from Jet A-1 by 58-86% for various engine load conditions. BC emissions from the 100% FT-SPK fuel were lower than from the Jet A-1 by 70-98%. Both the refractory and non-refractory PN emissions from these fuels were lower by comparable magnitude when compared to that from Jet A-1.
Chan, Tak W., Chishty, Wajid, Davison, Craig, Buote, David
Finite Element Analysis Simulation of a Fireproof Test for an Aircraft Propulsion Engine Mount Structure Made of Titanium2015-01-26219/15/2015
Aviation regulations requires that engine mounts, and other flight structures located in designated fire zones must be constructed of fireproof material so that they are capable of withstanding the effects of fire. Historically, steel is defined as being inherently fireproof, however, titanium was not. Therefore, a fireproof test was conducted using 6AL-4V titanium structure for the attachment of the propulsion system on a mid-size business jet to satisfy FAA Federal Aviation Requirement 25.865. To determine if the titanium structure would be able to support normal operating loads during the fire event, finite element analysis was performed on the titanium structure simulating the fire test. The fire test simulates a fire on the aircraft from the propulsion system by using a burner with jet fuel exposing the component to a 2000 °F (1093°C) flame. The 2000 °F (1093°C) Flame is calibrated based on FAA Advisory Circular AC20-135. The 2000 °F (1093°C) flame is modeled as a series of convection coefficients across the entire surface of the component. The conductive and convective thermal properties are used for the finite element analysis (FEA) model to simulate the heat transfer effects of the flame. A thermal transient analysis was performed to determine the component temperatures and correlation to the fire test showed excellent agreement. The peak temperatures in the vicinity of the flame on the titanium structure was about 1500 °F (816°C) but much lower at locations that were shielded by the structure. The transient thermal analysis also showed that after about 10 minutes the temperatures appeared to be at steady state conditions.
Leicht, Douglas
The Jet Fuel Hydrodynamic Cavitation Bubble Size with Cavitation Power and Energy from Rayleigh-Plesset Equation2015-01-23899/15/2015
Cavitation erosion in aircraft engine and control systems is a major concern in hydrodynamic power units. In developing turbulent flow of low pressure and high velocities, a certain amount of cavitation erosion is not unusual. Cavitation can occur with the presence of fuel vapor or air bubbles dissolved in the fuel tank that are transported through the system. Cavitation erosion is caused by collapse of the bubble, which occurs violently and creates a pressure shock wave of fluid. Striking a solid surface, the shock wave can cause progressive damage if it persists. A kinetic cavitation power rate is developed to make a meaningful estimation of the cavitation erosion rate theoretically, which then can be validated with laboratory experiments. Theoretically, we manipulate parameters such as bubble size, collapse pressure, and energy for a given fuel system design, finding variation within each component of the system. However, cavitation erosion rates vary wildly even when relative developments and comparisons are made. These variations are attributed to the simplicity of governing equations, boundary condition settings, and bubble sizing and geometry assumption differences of given derivation formulations. The jet fuel's bubble size, collapsing pressure, and surrounding fluid pressure, influenced by fuel properties due to temperature variation, appear to be the key factors in cavitation power and energy when predicting component life and degradation of efficiency in engine control systems.
Ni, William W., Cass, Michael, Bartholme, Daniel
A Fuel Surrogate Validation Approach Using a JP-8 Fueled Optically Accessible Compression Ignition Engine2015-01-09064/14/2015
An experimental fuel surrogate validation approach is proposed for a compression ignition application, and applied to validate a Jet-A POSF 4658 fuel surrogate. The approach examines the agreement of both physical and chemical properties of surrogate and target fuels during validation within a real compression-ignition engine environment during four sequential but distinct combustion phases. In-cylinder Mie Scattering measurements are applied to evaporating sprays to compare the behavior of the surrogate, its target fuel, and for reference, n-heptane. Early mixture formation and low temperature reaction behavior were investigated using 2-D broadband chemiluminescence imaging, while high temperature ignition and combustion chemistry were studied using OH chemiluminescence imaging. The optical measurements were combined with cylinder pressure-based combustion analysis, including ignition delay and premixed burn duration, to validate the global behavior of the surrogate. Engine-out UHC, NO and soot emissions were also compared at different intake conditions, injection pressures and injection strategies. The proposed approach can provide validation data for further numerical engine combustion modeling and kinetic mechanism validation. The results show the surrogate was able to match the spray behavior, high temperature radical distribution, high temperature ignition delay, and the premixed burn duration of the target Jet-A fuel. Reasonable agreement was observed between low temperature ignition delay and radical distribution. The surrogate also captures the trend of the effects of intake conditions and injection pressure when single or double injections are used.
Yu, Xin, Luo, Xi, Jansons, Marcis, Kim, Doohyun, Martz, Jason, Violi, Angela
Propulsion: Energy Sources14AERP10_0110/1/2014
Flying on Vegetation: Airlines, aircraft companies, and other stakeholders are taking the long view in developing sustainable alternatives to petroleum-based jet fuels. Fuel is expensive for airlines. According to sources interviewed for this article, fuel accounts for 30 to 50% of operating costs, depending on the size of the aircraft. And fuel prices remain volatile. At the same time, there are few alternatives to powering aircraft. While land transport has some available options-think electric vehicles and hydrogen fuel cells-aviation depends on liquid fuels with high energy density. Emissions are another concern. According to the Air Transport Action Group (ATAG), aviation is responsible for 2% of global manmade CO2 emissions.
Morey, Bruce
Flying on VegetationTBMG-2074410/1/2014
Fuel is expensive for airlines. According to sources interviewed for this article, fuel accounts for 30 to 50% of operating costs, depending on the size of the aircraft. And fuel prices remain volatile.
The Compatibility Study of Aircraft Fuel Tank Elastomers with Synthesized Paraffinic Kerosine and its Blends2014-01-90019/1/2014
The synthetic paraffinic kerosine (SPK) produced via HEFAs is of great interest for civil aviation industry as it exhibits an excellent thermal oxidative stability with significantly lower particulate matter emission. However, due to its aromatic free characteristics, the widespread use of SPK is limited by its compatibility with non-metal materials such as fuel tank elastomers. In this research the compatibility of SPK and its blends with widely used aircraft fuel tank elastomers were systematically studied. Experimental results demonstrated the volume swellability of all selected materials showed a linear relationship with volume percentage of No.3 jet fuel in SPK blend. The increase of volume percentage of No.3 jet fuel in the SPK blend increased volume swellability for all materials except fluorosilicone gasket. The alkyl benzenes and naphthalenes in the blend acted as the hydrogen donors, which facilitated the formation of polymer matrix and led to the increase of the distance between polymer chains. The poor volume swellability of fluorosilicone gasket was attributed to material itself highly fluorinated and relatively inert characteristics. Experimental results verified the material swelling performance was not only related to fuel properties but also influenced by material properties. Material elongation and hardness were also evaluated after aging in SPK and its blends at specified temperature for certain amount of time. Moreover, experimental results showed that the fuel properties were also impacted by the material used for fuel transportation. The synthetic rubber seal cap of storage can may cause high halogen content in the SPK and its blends.
Chen, Kai
Comparison of Soot Formation For Diesel and Jet-A in a Constant Volume Combustion Chamber Using Two-Color Pyrometry2014-01-12514/1/2014
The measurement of the two-color line of sight soot and KL factor for NO.2 diesel and jet-A fuels was conducted in an optical constant volume combustion chamber by using a high speed camera under 1000 K ambient temperature and varied oxygen concentration conditions. The ambient conditions were set as follows: four oxygen cases including 10%, 15%, 18% and 21% at 1000 K ambient temperature. KL factor and soot temperature were determined based on the two-color pyrometry technique using two band-pass filters with wavelengths of 650 nm and 550 nm. The results show that low soot temperature is observed in the upstream inner flame along the centerline, which is surrounded by high soot temperature regions, and a high KL factor is found in the same region with a low soot temperature. The results under different times suggest that soot temperature is higher for high O2 conditions during the entire flame development; meanwhile, both integrated KL factor and soot area decrease with the increase of O2 concentration. The two fuels share a similar trend of soot temperature and KL factor, however, diesel flame has a higher soot temperature and a larger high soot temperature area compared to jet-A flame. On the other hand, diesel flame shows a lower soot level during the quasi-steady state with a higher total soot level at the end of the combustion under low O2 conditions. A lower O2 concentration range from 10% to 15% is expected to have the possibility to achieve a simultaneous reduction of soot and NOx in sooting flames under the 1000 K ambient temperature condition.
Jing, Wei, Roberts, William, Fang, Tiegang
Role of Volatility in the Development of JP-8 Surrogates for Diesel Engine Application2014-01-13894/1/2014
Surrogates for JP-8 have been developed in the high temperature gas phase environment of gas turbines. In diesel engines, the fuel is introduced in the liquid phase where volatility plays a major role in the formation of the combustible mixture and autoignition reactions that occur at relatively lower temperatures. In this paper, the role of volatility on the combustion of JP-8 and five different surrogate fuels was investigated in the constant volume combustion chamber of the Ignition Quality Tester (IQT). IQT is used to determine the derived cetane number (DCN) of diesel engine fuels according to ASTM D6890. The surrogate fuels were formulated such that their DCNs matched that of JP-8, but with different volatilities. Tests were conducted to investigate the effect of volatility on the autoignition and combustion characteristics of the surrogates using a detailed analysis of the rate of heat release immediately after the start of injection. In addition, the effect of volatility on the spray dynamics was investigated by Schlieren imaging in an optically accessible rapid compression machine (RCM). The images supported the conclusions made in the IQT tests. Furthermore, apparent activation energies of JP-8 and surrogate fuels were determined based on the chemical delay periods, which could be considered as a new parameter for developing surrogate fuel.
Zheng, Ziliang, Lee, PO-I, Shrestha, Amit, Badawy, Tamer, Lai, Ming-Chia, Henein, Naeim, Sattler, Eric
Experimental Validation and Combustion Modeling of a JP-8 Surrogate in a Single Cylinder Diesel Engine2014-01-13764/1/2014
This paper presents the results of an experimental investigation on a single cylinder engine to validate a two-component JP-8 surrogate. The two-component surrogate was chosen based on a previous investigation where the key properties, such as DCN, volatility, density, and lower heating value, of the surrogate were matched with those of the target JP-8. The matching of the auto-ignition, combustion, and emission characteristics of the surrogate with JP-8 was investigated in an actual diesel engine environment. The engine tests for the validation of the surrogate were conducted at an engine speed of 1500 rpm, a load of 3 bar, and different injection timings. The results for the cylinder gas pressure, ignition delay period, rate of heat release, and the CO, HC, and NOx emissions showed a good match between the surrogate and the target JP-8. However, the engine-out particulate matter for the surrogate was lower than that for the JP-8 at all tested conditions. These findings are presented and discussed in the paper. Additionally, a reduced surrogate fuel model was constructed and was implemented in three-dimensional CFD simulation for the predictions of the cylinder gas pressure, rate of heat release, and engine-out emissions of the tested surrogate. The CFD results were found to be in good agreement with the experimental data.
Shrestha, Amit, Joshi, Umashankar, Zheng, Ziliang, Badawy, Tamer, Henein, Naeim, Sattler, Eric, Schihl, Peter
2013 Create the Future Design: Transportation & Automotive Category WinnerTBMG-1774411/1/2013
Carl Lawrence, Becky English, Graham Hill, John Murino, Elaine Thorndike, Gaby Aweida, Carl Talkington, Rob Kammerling, Kim Hedberg, Nancy Balch, Ilse Gayl and Ron Gremban Swift Tram, Inc., Boulder, CO
Comparison and Evaluation of Wear, Performance and Emission of Diesel, Karanja Oil Biodiesel and JP-8 in a Military 585 kW CIDI Engine2013-01-265810/14/2013
Investigating the impact of Karanja oil biodiesel and JP-8 fuel on diesel engine performance, emission and wear are very important for military track and wheeled vehicles due to their great potential as alternative fuels. In the present study, a military 585 kW CIDI engine was fuelled and tested with diesel, Karanja oil biodiesel and JP-8 respectively. The performances of fuels were evaluated in terms of brake horse power, specific fuel consumption, brake specific energy consumption, brake mean effective pressure, thermal efficiency and heat release rates. The emission of carbon monoxide (CO), unburnt hydrocarbon (UHC), and oxides of nitrogen NOx with the three fuels were also compared. Both Karanja oil, after transesterification and JP-8 exhibit the properties (density, viscosity and calorific value) within acceptable limits of ASTM standard. Performance of both JP-8 and pure Karanja oil biodiesel were slightly lower than diesel. Emissions of CO and UHC were found lower with both Karanja oil biodiesel and JP-8 as compared to diesel fuel. However, only JP-8 fuel had lower NOx emission whereas Karanja oil biodiesel had 10% higher NOx emission. The engine wear was also tested after a 100 hours run.
Pandey, Anand Kumar, Nandgaonkar, Milankumar
Camelina-Based Biofuel Shows Advantages in Turboprop13AERD1001_0210/1/2013
Researchers within the government of Canada see the need to improve the emissions performance of the Rolls-Royce T56 engine, which despite its age, remains a workhorse for its military aircraft fleet. In the United States, more than 200 billion gallons of liquid fuel is produced each year in a ratio of about 7:2:1 for gasoline, diesel, and jet fuel, respectively. With international air traffic expected to increase in the long term, the cost of aviation fuel will continue to rise unless current production can be increased. To address the global fuel challenges and economic sustainability, the International Air Transport Association (IATA) in June 2009 committed the airline industry to achieving a continuous improvement in fuel efficiency of 1.5% per year from 2009 to 2020, reaching carbon-neutral growth by 2020, and achieving a 50% absolute reduction in carbon emissions by 2050.
The Development of Novel Fuel Dehydrating Icing Inhibitors2013-01-21699/17/2013
Dissolved water is a normal component of jet fuel which is vapourised during combustion; however, free water is a contaminant that can starve engines, freeze to form ice crystals capable of blocking fuel feeds, support microbial growth, and contribute towards corrosion. Jet fuel may be protected from the potentially hazardous effects of free-water using biocides and icing/corrosion inhibitors. This investigation seeks to identify novel chemical approaches to the dual management of both water contamination and ice formation in jet fuel. The strategy of using organic molecules as dehydrating agents remains a relatively neglected approach perhaps because of the complexity of the physical organic chemistry involved in developing and refining these systems. However, organic molecules with well characterised dehydrating properties - such as ortho esters, acetals, hemiacetals, ketals, and hemiketals - present themselves as an excellent starting-point for the development and optimisation of novel Fuel Dehydrating Icing Inhibitors (FDII). This paper describes our systematic approach towards the development of jet fuel additives which are kinetically fast, selective, lipophilic water scavengers that produce, upon hydrolysis, a hydrophilic ice inhibitor. A brief human and environmental toxicological screening of candidates is described. We anticipate that this class of FDII represents a novel approach towards protecting jet fuel against the effects of water contamination.
Repetto, Sonia L., Costello, James F., De Lacy Costello, Benjamin, Ratcliffe, Norman M., Lam, Joseph K.-W.
Immediate Impacts on Particulate and Gaseous Emissions from a T56 Turbo-Prop Engine Using a Biofuel Blend2013-01-21319/17/2013
Adoption of hydro-processed esters and fatty acid biojet fuels is a critical component for the sustainability of the aviation industry. Aviation biofuels reduce pollution and provide alternatives to conventional fossil fuels. A study of the impacts of biofuels on emissions from a T56 turbo-prop engine was undertaken as a joint effort among several departments of the Government of Canada. In this study, particulate (including particle number and black carbon (BC) mass) and regulated gaseous emissions (CO2, CO, NO, NO2, THC) were characterized with the engine operating on conventional F-34 jet fuel and jet fuel blended with camelina-based hydro-processed biojet fuel (C-HEFA) by 50% in volume. Emissions characterization, conducted after 20-hour ground engine durability tests, showed immediate significant reductions in particle number and BC mass when the engine was operated on the C-HEFA blend. Operating at high speed ground idle (HSGI) using the C-HEFA blend reduced particle number and BC mass emissions by 31% and 50%, respectively. At Take-off engine mode, particle number and BC mass reductions were 22% and 32%, respectively. In addition, particles generated from the C-HEFA blend were also observed to be slightly smaller than those generated from the conventional jet fuel by 2-4 nanometer (nm). CO emissions from the C-HEFA blend were lower by 4-6%. CO2 emissions from the C-HEFA blend were lower by approximately 1%, consistent with the difference in hydrocarbon ratios in the C-HEFA blend.
Chan, Tak W., Pham, Vinh, Chalmers, Jennifer, Davison, Craig, Chishty, Wajid, Poitras, Pierre
Control of Fuel Octane for Knock Mitigation on a Dual-Fuel Spark-Ignition Engine2013-01-03204/8/2013
A two-port fuel-injection (PFI) system is added to a Rotax 914 four-cylinder spark-ignition engine to allow two fuels of different reactivity to be injected simultaneously in order to vary the fuel octane number during engine operation. Engine performance using the dual-fuel PFI system is compared to that using injection of primary-reference-fuel (PRF) blends via a single-PFI system for fuel octane ratings of 50, 70, and 87 octane. The on-the-fly octane control of dual-PFI system is found to control fuel-octane well enough to produce maximum indicated mean effective pressure (IMEPn) results within ± 2% of single-PFI PRF IMEPn results. IMEPn is compared among dual-PFI blends from 20 to 87 octane, neat n-heptane, neat JP-8, and JP-8/isooctane blends. Maximum IMEPn for these fuels is established for the Rotax 914 engine operating from 2500 to 5800 rev/min. IMEPn limitations for dual-PFI blends of JP-8 and isooctane are investigated at typical general-aviation cruise-power requirements to establish the volume proportion of JP-8 that can be used to sustain flight. The octane value of the sample of JP-8 tested is ∼ 20, and enabling JP-8 cruise operation requires a 2.5 - 3.5-bar shift in maximum IMEPn with JP-8. Results for typical cruise operation using JP-8/isooctane blends show that a maximum volume flow proportion of 88% JP-8 at low-load cruise, and 40% at high-load cruise could be used to sustain flight. These results reveal low-load neat JP-8 cruise as a possibility if the octane appetite of the Rotax 914 is reduced.
Baranski, Jacob, Anderson, Eric, Grinstead, Keith, Hoke, John, Litke, Paul
Calculation of Heating Value for Diesel Fuels Containing Biodiesel2013-01-11394/8/2013
Biodiesel, a fuel comprised of mono-alkyl esters of long-chain fatty acids also known as Fatty Acid Methyl Esters(FAME), derived from vegetable oils or animal fats, has become an important commercial marketplace automotive fuel in the United States (US) and around the world over last few years. FAME biodiesels have many chemical and physical property differences compared to conventional petroleum based diesel fuels. Also, the properties of biodiesel vary based on the feedstock chosen for biodiesel production. One of the key differences between petroleum diesel fuels and biodiesel is the energy content. The energy content, or heating value, is an important property of motor fuel, since it directly affects the vehicle fuel economy. While the energy content can be measured by combustion of the fuel in a bomb calorimeter, this analytical laboratory testing is time consuming and expensive. It would be more convenient to estimate the energy content from other commonly measured fuel properties. Several standardized empirical methods have been developed in the past for estimating the energy content of hydrocarbon fuels such as gasoline, diesel fuel, and jet fuel. However, with the addition of biodiesel to petroleum diesel fuel, the estimation methods developed for hydrocarbon diesel fuels are not very accurate for use with biodiesel blends. This paper summarizes heating value test results from different biodiesel blends representing the most common biodiesel feedstocks. New lower heating value predictive model equations are proposed for diesel fuel blends containing biodiesel and the results from standardized measurement tests are compared to the calculated values. This paper expands the scope of the empirical equations proposed in the SAE paper 2010-01-1571 for gasoline-ethanol blends to cover diesel fuel blends containing biodiesel.
Lopes, Shailesh Martin, Furey, Robert, Geng, Pat
Combustion and Emissions Characteristics of JP-8 Blends and ULSD #2 with Similar CN in a Direct Injection Naturally Aspirated Compression Engine2013-01-16824/8/2013
"The Single Fuel Forward Policy" legislation enacted in the United States mandates that deployed U.S. military ground vehicles must be operable with aviation fuel (JP-8). This substitution of JP-8 for diesel raises concerns about the compatibility of this fuel with existing reciprocating piston engine systems. This study investigates the combustion, emissions, and performance characteristics of blends of JP-8 and Ultra Low Sulfur Diesel (ULSD) fuels with similar cetane numbers (CN), 48 (JP-8) and 47(ULSD), respectively, in a direct injection (DI) compression ignition engine over the load range of 3-8 bar imep at 1400 rpm. The results showed that JP-8 blends and ULSD had ignition delays ranging from approximately 1.0-1.4 ms and an average combustion duration time in the range of 47-65 CAD. Cylinder maximum heat flux values were found to be between 2.0 and 4.4 MW/m₂, with radiation flux increasing much faster than convection flux while increasing the imep. Combustion maximum bulk temperature was in the range of 1700 K to 2500K, and also increased with load. Both mechanical and overall efficiencies increased with imep at constant speed but were minimally influenced by the fuel blend. Soot showed an increase at higher loads ranging between 0.01-0.18 g/kWh while NOx increased with higher loads and higher cycle temperatures. Carbon dioxide (CO₂) emissions showed an increase in value by increasing imep at constant speed while the UHC (unburned hydrocarbons) emissions decreased with load and maintained similar for all blends at constant imep. The results suggest that JP-8 and ULSD with similar CN have highly comparable combustion characteristics in a DI compression ignition engine despite differences in fuel properties and that CN is the paramount characteristic in comparing ULSD and JP-8.
Soloiu, Valentin, Ochieng, Henry, Weaver, Jabeous, Duggan, Marvin, Harp, Spencer, Vlcek, Brian, Jenkins, Craig, Jansons, Marcis
Investigation of Low-Temperature Combustion in an Optical Engine Fueled with Low Cetane Sasol JP-8 Fuel Using OH-PLIF and HCHO Chemiluminescence Imaging2013-01-08984/8/2013
Low cetane JP-8 fuels have been identified as being difficult to use under conventional diesel operation. However, recent focus on low-temperature combustion (LTC) modes has led to an interest in distillate hydrocarbon fuels having high volatility and low autoignition tendency. An experimental study is performed to evaluate low-temperature combustion processes in a small-bore optically-accessible diesel engine operated in a partially-premixed combustion mode using low-cetane Sasol JP-8 fuel. This particular fuel has a cetane number of 25. Both single and dual injection strategies are tested. Since long ignition delay is a consequence of strong autoignition resistance, under the conditions examined, low cetane Sasol JP-8 combustion can only take place with a double injection strategy: one pilot injection event in the vicinity of exhaust TDC and one main injection event near firing TDC. In this work, the effects of autoignition properties are examined by comparing the behavior of a high cetane number JP-8 fuel with that of a low CN Sasol JP-8. The double injection strategy also served to reduce pressure rise rates during operation at light load (2 bar IMEP) conditions. Dual injection timing is optimized for peak IMEP, at which point simultaneous OH Planar Laser-Induced Fluorescence (OH-PLIF) and high-speed crank-angle-resolved HCHO chemiluminescence imaging are performed to analyze the partially-premixed combustion process. Fuel efficiency and engine-out emissions performance are also presented. In terms of IMEP, low CN Sasol JP-8 fuel is shown to be a satisfactory fuel for low-temperature combustion under light-load condition using the proper dual injection strategy. However, partially-premixed combustion operation in this work results in higher UHC emissions and lower fuel efficiency when compared with the high cetane JP-8 fuel.
Zha, Kan, Yu, Xin, Lai, Ming-Chia, Jansons, Marcis
Advanced Glow Plug for Heavy Fuels Applications2013-01-17164/8/2013
With current DoD goals of switching to a common battlefield logistics fuel, there is a significant push to develop technologies that allow small, high-powered engines such as used in unmanned aerial, marine, and ground vehicles, typically fueled by volatile fuels such as gasoline, to operate on heavy fuels such as JP-8. In this paper, the feasibility of catalytic glow plugs as an enabling component for the use of heavy fuels both as a retrofit to existing engines as well as new engine designs is demonstrated. Compared to standard spark igniters and non-catalytic glow plugs, the use of catalytic glow plugs will provide benefits including lower required compression ratio, improved igniter life, reduced energy requirements, and overall reduction in system weight and size. The catalytic glow plugs were shown to have a significant increase in surface temperature (180+°C) with impingement of a fuel spray and this increase was maintained over many cycles of impingement. Engine testing demonstrated the use of catalyst-allowed stable engine operation at reduced power requirements with durability exceeding 150 hrs. This technology would allow the use of logistic heavy fuels in small engines, while potentially reducing power supply weight and engine complexity and weight, both of which would allow greater range and/or payload capacity.
Baird, Benjamin, Etemad, Shahrokh
Sleeve, Hose Assembly, Fire ProtectionAS1072E (Historical)1/2/2013
This standard defines the requirements for bulk protective sleeve to provide fire resistance for aircraft hose assemblies, which will enable these assemblies to meet the requirements of AS1055. NOTE: Use of this sleeve does not eliminate the need to demonstrate that the sleeved assemblies will meet the applicable requirements of AS1055.
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
Energy Optimized Aircraft: What is it and how do we make one?2012-01-217910/22/2012
Efforts are underway to develop technologies to create a more Energy Optimized Aircraft (EOA). The question becomes how should one define an Energy Optimized Aircraft and how should energy optimization be measured to determine what is optimal? This paper provides a top level point of view for the goal of an Energy Optimized Aircraft. It outlines how one should approach the design of such an aircraft, the relevant vehicle systems technologies to enable energy optimization for fighter aircraft, and potential aircraft level measurands for determining degrees of goodness associated with incorporating different technologies. The top-to-bottom approach is provided for traceability of technologies being developed to aircraft and mission level goals.
Griggs, Steven C., Iden, Steven Mark, Lamm, Peter T.
Soot Volume Fraction and Morphology of Conventional, Fischer-Tropsch, Coal-Derived, and Surrogate Fuel at Diesel Conditions2012-01-06784/16/2012
Future fuels will come from a variety of feed stocks and refinement processes. Understanding the fundamentals of combustion and pollutants formation of these fuels will help clear hurdles in developing flex-fuel combustors. To this end, we investigated the combustion, soot formation, and soot oxidation processes for various classes of fuels, each with distinct physical properties and molecular structures. The fuels considered include: conventional No. 2 diesel (D2), low-aromatics jet fuel (JC), world-average jet fuel (JW), Fischer-Tropsch synthetic fuel (JS), coal-derived fuel (JP), and a two-component surrogate fuel (SR). Fuel sprays were injected into high-temperature, high-pressure ambient conditions that were representative of a practical diesel engine. Simultaneous laser extinction measurement and planar laser-induced incandescence imaging were performed to derive the in-situ soot volume fraction. From experiments, it was found that fuels with long lift-off length generally produce less soot but fuel molecular structure also affects soot formation. For instance, JP fuel with the longest lift-off length among tested fuels showed higher soot than JS because of higher cycloparaffinic content. Attributed to variations in both lift-off length and molecular structure, the level of total soot within the fuels jet in decreasing order was D2=SR≻JW≻JP≻JC≻JS. Further details of the soot processes were clarified by sampling the soot particles from within the reacting jet by means of a thermophoretic probe, with subsequent analysis by transmission electron microscopy (TEM). Analyzed TEM images of soot particles showed a marked variation in the soot particle structures depending on the fuel type and were consistent with the soot volume fraction trend.
Kook, Sanghoon, Pickett, Lyle M.
Effect of Intake Pressure and Temperature on the Auto-Ignition of Fuels with Different Cetane Number and Volatility2012-01-13174/16/2012
This paper investigates the effect of boost pressure and intake temperature on the auto-ignition of fuels with a wide range of properties. The fuels used in this investigation are ULSD (CN 45), FT-SPK (CN 61) and two blends of JP-8 (with CN 25 and 49). Detailed analysis of in-cylinder pressure and rate of heat release traces are made to correlate the effect of intake pressure and injection strategy on the events immediately following start of injection leading to combustion. A CFD model is applied to track the effect of intake pressure and injection strategy on the formation of different chemical species and study their role and contribution in the auto-ignition reactions. Results from a previous investigation on the effect of intake temperature on auto-ignition of these fuels are compared with the results of this investigation.
Jayakumar, Chandrasekharan, Zheng, Ziliang, Joshi, Umashankar, Bryzik, Walter, Henein, Naeim, Sattler, Eric
Comparison of In-Cylinder Soot Evolution in an Optically Accessible Engine Fueled with JP-8 and ULSD2012-01-13154/16/2012
Due to the single fuel concept implemented by the US military, the soot production of diesel engines fueled with JP-8 has important implications for military vehicle visual signature and survivability. This work compares in-cylinder soot formation and oxidation of JP-8 and ULSD in a small-bore, optical diesel engine. Experimental engine-out soot emission measurements are compared to crank-angle resolved two-color measurements of soot temperature and optical thickness, KL. A 3-D chemical kinetic-coupled CFD model with line of sight integration is employed in order to investigate the soot distribution in a 2-D projection associated with the imaging plane, as well as to aid in interpreting the third dimension along the optical depth which is not available within the experimental work. The study also examines the effect of volatility on soot emission characteristics by CFD simulation. With the same injection pressure and timing for both fuels considered, heat release analysis shows JP-8 has more energy release than ULSD, however two color measurements indicate JP-8 produces less in-cylinder soot throughout the cycle as well as lower engine out measurements compared to ULSD. Furthermore, JP-8 is found to have a lower soot temperature and less high temperature areas than ULSD. A line of sight integration technique is applied to the CFD (Reaction Design FORTE) output to compare the simulation results with experimental high speed images. The model has good agreement with the experimental results, as does the predicted soot temperature and KL factor with the two color experimental measurements. However, interpretation of the two-color line of sight images obtained from the CFD simulation indicated that the measurement of the KL factor will be affected by the amount of radiation intensity available to a camera characterized by a finite dynamic range. Finally, the effect of fuel volatility is investigated using the CFD model by varying fuel evaporation properties. It is observed that the high volatility fuels, such as JP-8, exhibit lower engine out soot emissions due to better fuel mixing and increased local equivalence ratio homogeneity.
Yu, Xin, Zha, Kan, Florea, Radu, Jansons, Marcis
Automotive Engineering: The Future is TodayTBMG-130623/1/2012
The Ford Focus Electric is the industry’s first car to feature 100 percent sustainable clean technologies in interior materials, including seat fabrics with Unifi’s REPREVE®-branded fiber made from recycled plastic bottles. Ford, through the use of REPREVE, plans to divert about 2 million post-consumer plastic bottles for use in the new Focus Electric and other new vehicles for this model year. The Focus Electric contains REPREVE-based fabrics that are made from the equivalent of about 22 recycled PET (polyethylene terephthalate) bottles in each car.
Nozzles and Ports – Gravity Fueling Interface Standards for Civil AircraftAS1852D (Current)1/3/2012
This SAE Aerospace Standard (AS) defines the maximum allowable free opening dimensions for airframe fueling ports on civil aircraft that require the exclusive use of gasoline as an engine fuel, and the minimum free opening dimensions for airframe fueling ports on civil aircraft that operate with turbine fuels as the primary fuel type and with gasoline as the emergency fuel type. This SAE Aerospace Standard (AS) also defines the features and dimensions for airframe refueling ports on civil aircraft that require the exclusive use of turbine fuel as an engine fuel. In addition, this document defines the minimum fuel nozzle spout dimensions for turbine fuel ground service equipment, and the maximum fuel nozzle spout diameter for gasoline ground service equipment.
AE-5A Aerospace Fuel, Inerting and Lubrication Sys Committee
Gaseous and Particle Emissions from a Turbo-Jet Engine Operating on Alternative Fuels at Simulated Altitudes2011-01-259710/18/2011
Gaseous and particle emission assessments on a 1.15 kN-thrust turbojet engine were conducted at five altitudes in an altitude chamber with Jet A-1 fuel, pure Fischer Tropsch (FT), and two mixed fuels of JP-8 with FT or Camelina-based hydro-processed jet fuels. In general, lower emissions in CO₂, NOx, and particle number as well as higher emissions in CO and THC were observed at higher altitudes compared to lower altitudes. These observations, which were similar for all test fuels, were attributed to the reduced combustion efficiency and temperature at higher altitudes. The use of alternative fuels resulted in lower CO₂ emissions, ranging from 0.7% to 1.7% for 50% to 100% synthetic fuel in the fuel mixture at various altitudes. In terms of CO, the use of 100% FT fuel resulted in CO reduction up to 9.7% at 1525 m altitude and up to 5.9% at 9145 m altitude. Significant reduction in particle diameter, number and mass emission rates were observed with the use of alternative fuels due to the low aromatic and sulfur content in the fuels. Higher reductions were observed for increasing percentage of the alternative synthetic fuel in the fuel mixture. With the use of pure FT fuel, up to 80% and 96% reductions in particle number emissions were observed at 1525 m and 9145 m altitudes, respectively. In comparison, a larger particle reduction benefit was observed for the Camelina-based hydro-processed jet fuel than for the FT fuel.
Chan, Tak W., Cuddihy, Kevin, Chishty, Wajid, Davison, Craig, McCurdy, Mark, Barton, Peter
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