Jet Fuel Thermal Stability - Lab Testing for JP8+100

2002 ◽  
Author(s):  
David R. Forester ◽  
Bharat B. Malik ◽  
Spencer E. Taylor
Keyword(s):  
Thermal Stability ◽  
Jet Fuel

JP-8+100: The Development of High-Thermal-Stability Jet Fuel

1996 ◽  
Vol 118 (3) ◽  
pp. 170-179 ◽  
Author(s):  
S. P. Heneghan ◽  
S. Zabarnick ◽  
D. R. Ballal ◽  
W. E. Harrison
Keyword(s):  
Thermal Stability ◽  
Jet Fuel ◽  
High Thermal Stability ◽  
Maximum Temperature ◽  
Additive Package ◽  
Primary Coolant ◽  
Free Radical Theory ◽  
Radical Theory ◽  
Current Availability ◽  
Strategic Factors

Jet fuel requirements have evolved over the years as a balance of the demands placed by advanced aircraft performance (technological need), fuel cost (economic factors), and fuel availability (strategic factors). In a modern aircraft, the jet fuel not only provides the propulsive energy for flight, but also is the primary coolant for aircraft and engine subsystems. To meet the evolving challenge of improving the cooling potential of jet fuel while maintaining the current availability at a minimal price increase, the U.S. Air Force, industry, and academia have teamed to develop an additive package for JP-8 fuels. This paper describes the development of an additive package for JP-8, to produce “JP-8+100.” This new fuel offers a 55°C (100°F) increase in the bulk maximum temperature (from 325°F to 425°F) and improves the heat sink capability by 50 percent. Major advances made during the development of JP-8+100 fuel include the development of several new quantitative fuel analysis tests, a free radical theory of autooxidation, adaptation of new chemistry models to computational fluid dynamics programs, and a nonparametric statistical analysis to evaluate thermal stability. Hundreds of additives were tested for effectiveness, and a package of additives was then formulated for JP-8 fuel. This package has been tested for fuel system materials compatibility and general fuel applicability. To date, the flight testing has shown an improvement in thermal stability of JP-8 fuel. This improvement has resulted in a significant reduction in fuel-related maintenance costs and a threefold increase in mean time between fuel-related failures. In this manner, a novel high-thermal-stability jet fuel for the 21st century has been successfully developed.

JP-8+100 - The development of high thermal stability jet fuel

1996 ◽  
Author(s):  
S. Heneghan ◽  
S. Zabarnick ◽  
D. Ballal ◽  
W. Harrison, III
Keyword(s):  
Thermal Stability ◽  
Jet Fuel ◽  
High Thermal Stability

scholarly journals Jet Fuel Deposition and Oxidation: Dilution, Materials, Oxygen, and Temperature Effects

1995 ◽  
Author(s):  
Steven Zabarnick ◽  
Paula Zelesnik ◽  
Rebecca R. Grinstead
Keyword(s):  
Thermal Stability ◽  
Electrode Materials ◽  
Batch Reactor ◽  
Jet Fuel ◽  
Pressure Measurements ◽  
Good Technique ◽  
Antioxidant Concentration ◽  
Fuel Deposition

The quartz crystal microbalance (QCM) and pressure measurements are used for determination of jet fuel thermal stability in a batch reactor. The QCM is able to monitor extremely small amounts of deposition in situ, while the pressure measurements provide qualitative data on the oxidation process. The dependence of the deposition amount was monitored as a function of the oxygen availability for two fuels. Also, the effect of QCM electrode materials was investigated. Deposition and oxidation were compared for the following electrode materials: gold, aluminum, silver, and platinum. We also studied the effect of dilution on oxidation and deposition. Jet fuel was diluted with increasing amounts of hydrocarbon solvent. It was observed that this dilution procedure can help characterize a fuel’s effective antioxidant concentration. Fuel dilution is also shown to be a good technique for improving thermal stability characteristics of poor fuels. Additionally we have studied the temperature effect on deposition for two fuels over the range 140 to 180 C.

scholarly journals Studies of Jet Thermal Stability in a Flowing System

1992 ◽  
Author(s):  
S. P. Heneghan ◽  
C. R. Martel ◽  
T. F. Williams ◽  
D. R. Ballal
Keyword(s):  
Thermal Stability ◽  
Oxygen Consumption ◽  
Jet Fuel ◽  
Total Carbon ◽  
Threshold Temperature ◽  
Jet Fuels ◽  
Test Duration ◽  
Fuel Temperature ◽  
Test Rig ◽  
Carbon Deposits

A flowing, single-pass heat exchanger test rig, with a fuel capacity of 189 litres, has been developed to evaluate jet fuel thermal stability. This so called, “Phoenix Rig” is capable of supplying jet fuel to a 2.15 mm I.D. tube at a pressure up to 3.45 MPa, fuel temperature up to 900K, and a fuel-tube Reynolds number in the range 300–11,000. Using this test rig, fuel thermal stability (carbon deposition rate), dissolved oxygen consumption, and methane production were measured for three baseline jet fuels and three fuels blended with additives. Such measurement were performed under oxygen-saturation or oxygen-starved conditions. Tests with all of the blended fuel samples showed a noticeable improvement in fuel thermal stability. Both block temperature and test duration increased the total carbon deposits in a nonlinear fashion. Interestingly, those fuels that need a higher threshold temperature to force the consumption of oxygen exhibited greater carbon deposits than those that consume oxygen at a lower temperature. These observations suggested a complicated relationship between the formation of carbon deposits and the temperature-driven consumption of oxygen. A simple analysis, based on a bi-molecular reaction rate, correctly accounted for the shape of the oxygen consumption curve for various fuels. This analysis yielded estimates of global bulk parameters of oxygen consumption. The test rig yielded quantitative results which will be very useful in evaluating fuel additives, understanding the chemistry of deposit formation, and eventually developing a global chemistry model.

scholarly journals Extended Duration Thermal Stability Test of Improved Thermal Stability Jet Fuels

1995 ◽  
Author(s):  
Gordon L. Dieterle ◽  
Kenneth E. Binns
Keyword(s):  
Thermal Stability ◽  
Heat Exchanger ◽  
Jet Fuel ◽  
Stability Test ◽  
Bulk Temperature ◽  
Jet Fuels ◽  
Test Results ◽  
Fuel Temperature ◽  
Extended Duration ◽  
Thermal Stability Of

A single-pass, dual heat exchanger system called the Extended Duration Thermal Stability Test (EDTST) system was developed for evaluating jet fuel thermal stability. Various JP-8 fuels and thermal stability additives have been evaluated in the system. The test results indicate that additives can substantially improve the thermal stability of conventional jet fuels. Relationships of bulk and wetted wall temperatures on coking deposits that form in heated tubes have also been evaluated. To date, tests conducted with EDTST have verified that additives can improve the thermal stability of JP-8 fuels. The goal of operating at wetted wall temperatures of 260°C (500°F) has been achieved. The goal for bulk fuel temperatures of 218°C (425°F) with no deposits has not been achieved. Additional additive candidates are to be evaluated in the EDTST system to identify additives that meet both the wetted wall and bulk fuel temperature goals of this program. However, if the bulk temperature goal cannot be totally achieved, the JP-8 fuel specification will most probably be changed to take advantage of the wetted wall temperature improvement already demonstrated by a JP-8+100 additive candidate.

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