Studies of Jet Fuel Thermal Stability in a Flowing System

1993 ◽  
Vol 115 (3) ◽  
pp. 480-485 ◽  
Author(s):  
S. P. Heneghan ◽  
C. R. Martel ◽  
T. F. Williams ◽  
D. R. Ballal
Keyword(s):  
Thermal Stability ◽  
Oxygen Consumption ◽  
Bimolecular Reaction ◽  
Jet Fuel ◽  
Total Carbon ◽  
Threshold Temperature ◽  
Test Duration ◽  
Fuel Temperature ◽  
Test Rig ◽  
Carbon Deposits

A flowing, single-pass heat exchanger test rig, with a fuel capacity of 189 liters, has been developed to evaluate jet fuel thermal stability. This “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 900 K, 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 bimolecular 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 fuels additives, understanding the chemistry of deposit formation, and eventually developing a global chemistry model.

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.

The Effects of Dissolved Oxygen Concentration, Fractional Oxygen Consumption, and Additives on JP-8 Thermal Stability

1997 ◽  
Vol 119 (4) ◽  
pp. 822-829 ◽  
Author(s):  
J. S. Ervin ◽  
T. F. Williams ◽  
S. P. Heneghan ◽  
S. Zabarnick
Keyword(s):  
Thermal Stability ◽  
Oxygen Consumption ◽  
Heat Exchanger ◽  
Dissolved Oxygen ◽  
Oxygen Concentration ◽  
Jet Fuel ◽  
Combined Effects ◽  
Fuel System ◽  
Dissolved Oxygen Concentration ◽  
Additive Package

Since dissolved oxygen participates in fuel deposit formation, knowledge of the effects of dissolved oxygen concentration on fuel thermal stability is critical for fuel system design. In this work, the combined effects of dissolved oxygen availability and additives on jet fuel thermal stability are studied. Experiments with JP-8 jet fuel were conducted in a three-part heat exchanger that simulated a complex thermal and flow environment. The dissolved oxygen content at the flow inlet was varied, and deposition was studied under conditions of either fractional or complete oxygen consumption. The effects of a thermal stability additive package were also studied. An intriguing result found with JP-8 fuels is an increase in deposits formed in heated regions for decreased oxygen consumption, but inverse behavior with the additive package.

scholarly journals The Effects of Dissolved Oxygen Concentration, Fractional Oxygen Consumption, and Additives on JP-8 Thermal Stability

1996 ◽  
Author(s):  
J. S. Ervin ◽  
T. F. Williams ◽  
S. P. Heneghan ◽  
S. Zabarnick
Keyword(s):  
Thermal Stability ◽  
Oxygen Consumption ◽  
Heat Exchanger ◽  
Dissolved Oxygen ◽  
Oxygen Concentration ◽  
Jet Fuel ◽  
Combined Effects ◽  
Fuel System ◽  
Dissolved Oxygen Concentration ◽  
Additive Package

Since dissolved oxygen participates in fuel deposit formation, knowledge of the effects of dissolved oxygen concentration on fuel thermal stability is critical for fuel system design. In this work, the combined effects of dissolved oxygen availability and additives on jet fuel thermal stability are studied. Experiments with JP-8 jet fuel were conducted in a three-part heat exchanger which simulated a complex thermal and flow environment. The dissolved oxygen content at the flow inlet was varied, and deposition was studied under conditions of either fractional or complete oxygen consumption. The effects of a thermal stability additive package were also studied. An intriguing result found with JP-8 fuels is an increase in deposits formed in heated regions for decreased oxygen consumption, but inverse behavior with the additive package.

Combustion Emission Measurements With Preheated Jet Fuel

2011 ◽  
Author(s):  
Qing-ping Zheng ◽  
Sangsig Yun ◽  
Dan Titirica ◽  
Sam Sampath ◽  
Ibrahim Yimer
Keyword(s):  
Temperature Effect ◽  
Experimental Tests ◽  
Jet Fuel ◽  
Operating Conditions ◽  
Cycle Performance ◽  
Fuel Temperature ◽  
Test Rig ◽  
Temperature Regimes ◽  
Aero Engines ◽  
Set Up

Jet fuel thermal stability at high temperature is receiving increased attention recently as advanced aero engines are being pushed to high power, high pressure and temperature regimes for improved engine cycle performance and low emissions. This paper describes the rig experimental tests to assess the high fuel temperature effect on combustor emissions. A special test rig facility has been designed and set up for emission measurements with preheated fuel. The purpose of the tests is to evaluate the combustor emission characteristics under nominal and elevated fuel temperatures. The scope of the project is two fold: (1) to design, procure and establish a dedicated hot fuel deoxygenation, fuel preheat facility that can reach temperature up to 600 °F (589 K); (2) to measure combustion emissions, mainly NOx, CO and UHC, at normal and elevated fuel temperature under representative engine operating conditions. The test rig has run for extended duration and proved reliable over the whole test campaign. Measured emission results show that fuel temperature effect on NOx, CO, UHC emissions are marginal, possibly due to the low emission capability of the sector combustor that is less sensitive to fuel inlet condition changes than other combustor designs. These results indicate a manageable risk for engine development with elevated fuel temperature from the emission viewpoint.

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.

scholarly journals Innovative Test Rig for Jet Fuels Thermal Stability Testing / Innowacyjne Stanowisko Badawcze Do Określania Stabilności Termicznej Paliw Lotniczych

2014 ◽  
Vol 29 (1) ◽  
pp. 15-22
Author(s):  
Jarosław Sarnecki
Keyword(s):  
Thermal Stability ◽  
Laboratory Test ◽  
Thermal Conditions ◽  
Standard Test ◽  
Test Method ◽  
Jet Fuels ◽  
Stability Testing ◽  
Test Rig ◽  
Standard Test Method ◽  
Laboratory Test Method

Abstract The article deals with laboratory test method for jet fuels thermal stability testing. Author described the reasons that led to test rig preparation, its construction and operation principles. Innovative test rig for jet fuels thermal stability testing enables research in wide thermal conditions and different pressures. Testing capabilities and advantages compared with currently used standard test method of jet fuels thermal stability testing according to ASTM D3241 have been also presented

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
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