Combustion Characteristics of Special Hydrocarbon Jet Fuels PDF Download

Author:
Publisher:
ISBN:
Category : Hydrocarbons
Languages : en
Pages : 162

View

Book Description

Author: W. W. HORSTMAN
Publisher:
ISBN:
Category :
Languages : en
Pages : 1

View

Book Description
The combustion performance of potential hydrocarbon fuels for supersonic aircraft jet engines was evaluated in a J-79 engine combustor. The combustor test conditions simulated full-scale engine operation at high altit des and supersonic speeds. As the inlet air pressure decreased, the combustion efficienc decreased. Differences in combustion efficiency were noted between 8 fuels at the various operating c n iti ns. A comparison of the fuel flow requirement for a constant urner temperature rise (thrust) at two test conditions indicated lowest fuel flow on a weight basis for a paraffinic fuel and a production type JP-6 fuel; lowest fuel flow on a volume basis was indicated for a naphthenic fuel and isopropylbicyclohexyl. At a more severe operating condition the isopropylbicyclohexyl indicated a low fuel flow requirement on both a weight and volume basis. The effect of fuel preheat on combustion efficiency was negligible. Combustor liner temperat re ere not affected appreciably by fuel differences. The carbon deposits were very light for all fuels. The fuels with the higher ASTM initial and 10% boiling points had higher ignition requirements at simulated altitude relight test conditions. (Author).

Author: W. S. Blazowski
Publisher:
ISBN:
Category :
Languages : en
Pages : 74

View

Book Description
Future anticipated changes in jet fuel character can be expected to have substantial combustion system effects. This report contributes technical information to assist in future definition of new jet fuel specifications formulated with the intent of minimizing total cost of system operation while maintaining performance and flight safety. The impact of lower fuel hydrogen content on combustor liner temperatures, smoke, and gaseous emissions has been evaluated and improved correlations with hydrogen content have been developed. Results obtained with the various fuel blends tested have confirmed the dominant influence of hydrogen content on combustion characteristics when compared to volatility and hydrocarbon type effects. Use of the new non-dimensional liner temperature parameter has also resulted in a good correlation of a wide variety of previous combustor data involving rich combustion systems.

Author: Colin William Curtis
Publisher:
ISBN:
Category :
Languages : en
Pages : 110

View

Book Description
Liquid propelled propulsion systems, which range from rocket systems to hypersonic scramjet and ramjet engines, require active cooling in order to prevent additional payload requirements. In these systems, the liquid fuel is used as a coolant and is delivered through micro-channels that surround the combustion chambers, nozzles, as well as the exterior surfaces in order to extract heat from these affected areas. During this process, heat exchange occurs through phase change, sensible heat extraction, and endothermic reactions experienced by the liquid fuel. Previous research has demonstrated the significant modifications in fuel composition and changes to the fuel's physical properties that can result from these endothermic reactions. As a next step, we are experimentally investigating the effect that endothermic reactions have on fundamental flame behavior for real hydrocarbon fuels that are used as rocket and jet propellants. To achieve this goal, we have developed a counter-flow flame burner to measure extinction limits of the thermally stressed fuels. The counter-flow flame system is to be coupled with a high pressure reactor, capable of subjecting the fuel to 170 atm and 873 K, effectively simulating the extreme environment that cause the liquid fuel to experience endothermic reactions. The fundamental flame properties of the reacted fuels will be compared to those of unreacted fuels, allowing us to determine the role of endothermic reactions on the combustion behavior of current hydrocarbon jet and rocket propellants. To quantify the change in transport properties and chemical kinetics of the reacting mixture, simultaneous numerical simulations of the reactor portion of the experiment coupled with a counterflow flame simulation are performed using n-heptane and n-dodecane.

Author: Bernard J. Wood
Publisher:
ISBN:
Category : Liquid propellants
Languages : en
Pages : 42

View

Book Description

Author: Meredith Colket
Publisher:
ISBN: 9781624106033
Category : Fuel switching
Languages : en
Pages : 0

View

Book Description
In summarizing the results obtained in the first five years of the National Jet Fuel Combustion Program (NJFCP), this book demonstrates that there is still much to be learned about the combustion of alternative jet fuels.

Author:
Publisher:
ISBN:
Category :
Languages : ja
Pages : 14

View

Book Description

Author: M. R. Riazi
Publisher: ASTM International
ISBN: 9780803133617
Category : Technology & Engineering
Languages : en
Pages : 425

View

Book Description
The last three chapters of this book deal with application of methods presented in previous chapters to estimate various thermodynamic, physical, and transport properties of petroleum fractions. In this chapter, various methods for prediction of physical and thermodynamic properties of pure hydrocarbons and their mixtures, petroleum fractions, crude oils, natural gases, and reservoir fluids are presented. As it was discussed in Chapters 5 and 6, properties of gases may be estimated more accurately than properties of liquids. Theoretical methods of Chapters 5 and 6 for estimation of thermophysical properties generally can be applied to both liquids and gases; however, more accurate properties can be predicted through empirical correlations particularly developed for liquids. When these correlations are developed with some theoretical basis, they are more accurate and have wider range of applications. In this chapter some of these semitheoretical correlations are presented. Methods presented in Chapters 5 and 6 can be used to estimate properties such as density, enthalpy, heat capacity, heat of vaporization, and vapor pressure. Characterization methods of Chapters 2-4 are used to determine the input parameters needed for various predictive methods. One important part of this chapter is prediction of vapor pressure that is needed for vapor-liquid equilibrium calculations of Chapter 9.

Author: National Academies of Sciences, Engineering, and Medicine
Publisher: National Academies Press
ISBN: 0309440998
Category : Technology & Engineering
Languages : en
Pages : 123

View

Book Description
The primary human activities that release carbon dioxide (CO2) into the atmosphere are the combustion of fossil fuels (coal, natural gas, and oil) to generate electricity, the provision of energy for transportation, and as a consequence of some industrial processes. Although aviation CO2 emissions only make up approximately 2.0 to 2.5 percent of total global annual CO2 emissions, research to reduce CO2 emissions is urgent because (1) such reductions may be legislated even as commercial air travel grows, (2) because it takes new technology a long time to propagate into and through the aviation fleet, and (3) because of the ongoing impact of global CO2 emissions. Commercial Aircraft Propulsion and Energy Systems Research develops a national research agenda for reducing CO2 emissions from commercial aviation. This report focuses on propulsion and energy technologies for reducing carbon emissions from large, commercial aircraftâ€" single-aisle and twin-aisle aircraft that carry 100 or more passengersâ€"because such aircraft account for more than 90 percent of global emissions from commercial aircraft. Moreover, while smaller aircraft also emit CO2, they make only a minor contribution to global emissions, and many technologies that reduce CO2 emissions for large aircraft also apply to smaller aircraft. As commercial aviation continues to grow in terms of revenue-passenger miles and cargo ton miles, CO2 emissions are expected to increase. To reduce the contribution of aviation to climate change, it is essential to improve the effectiveness of ongoing efforts to reduce emissions and initiate research into new approaches.

Author: Vincent J. Siminski
Publisher:
ISBN:
Category :
Languages : en
Pages : 242

View

Book Description
The purpose of this program was to determine, analytically and experimentally the extent to which the autoignition delay times of liquid hydrocarbons could be reduced by modification of the molecular structure or through the utilization of homogeneous additives and heterogeneous catalysts. To this end the autoignition delays of a number of different hydrocarbons were determined in three different experimental apparatus; a well-stirred reactor, a constant flow subsonic duct and a supersonic detached jet or ducted flow system. At one atmosphere pressure the velocity and temperature of the test devices were varied from subsonic to supersonic and from 300 to 1600 K respectively. No quantitative relationship could be established between the ignition lags measured in the constant flow system and the average residence times determined in the stirred reactor at the blow-out point. However, it is clear that the stirred reactor data more closely describe the total hydrocarbon combustion time than any 'pseudo ignition lag' associated with the hydrocarbon. Of the more than 25 different homogeneous additives tested, the strongest ignition promoters, by far, were found to be the alkyl nitrates and nitrites or nitric oxide and nitrogen dioxide. The presence of a platinum surface on the walls of the combustion chamber reduced the autoignition temperature of various hydrocarbons by 350 K. Fuel blends consisting of 15 volume percent n-propyl nitrate in either H-MCPD or Shelldyne-H were ignited and combusted in a piloted supersonic flow (Mach 1.5) over a temperature range of 300 to 1300 K.