Regularities of the change in the critical combustion thickness for porous low-gas pyrotechnic specimens

1994 ◽  
Vol 65 (5) ◽  
pp. 1105-1108
Author(s):  
G. M. Koledinskii ◽  
B. V. Novozhilov
Keyword(s):  
Critical Combustion

Some critical combustion aspects of reformulated heating fuels

Fuel ◽  
1995 ◽  
Vol 74 (2) ◽  
pp. 147-152 ◽  
Author(s):  
S.Win Lee ◽  
David P.C. Fung
Keyword(s):  
Critical Combustion

Assessment of Biofuels/Jet A-1 Blends to Meet Cold Start and Altitude Relight Requirements

2017 ◽  
Author(s):  
Joël Jean ◽  
Alain Fossi ◽  
Alain deChamplain ◽  
Bernard Paquet
Keyword(s):  
Negative Impact ◽  
Cold Start ◽  
Operating Pressure ◽  
Pressure Drops ◽  
Steam Ejector ◽  
Engine Testing ◽  
Almost All ◽  
Engine Components ◽  
Critical Combustion ◽  
Better Than

The certification of new fuels for aircraft applications requires preliminary extensive investigations for the most critical combustion phases. Especially, cold start and altitude relight of an aircraft gas turbine and thus its operating envelope could potentially be affected by the use of new fuels. To assess such effects, a test rig is designed using two different air-assist pressure atomizers. The ignition envelopes for seven different blends with a minimum of 50% Jet A-1 are compared to that of pure Jet A-1. Variation in combustor aerodynamics is accounted for by considering various pressure drops across the combustion chamber, and the ignition envelope is retrieved by finding the minimum and maximum fuel-air ratios leading to a successful ignition event. Effects of fuel physical properties, pressure and temperature which are critical factors for a successful ignition event are also investigated. To simulate cold start and altitude relight, a heat exchanger is used to cool air and fuel, while a bleed valve mounted between the combustor and a steam ejector is used to regulate the operating pressure. Globally, cold start for temperatures ranging from 10°C to −40°C, and the altitude relight for operating altitudes ranging from 4 572 m to 10 668 m, show that the lean limit for the seven blends of fuels are in some cases as good as, and for the other cases better than the pure Jet A-1. Some discrepancies are noted for altitude relight at 9 161 m and 10 688 m, for some biofuels with a minimum of 50% Jet A-1, suggesting a need of real engine testing before final approval. Apart from these isolate cases, almost all the biofuel blends with a minimum of 50% Jet A-1 are truly “drop-in” fuels and should qualify for aviation use since they do not present any negative impact on the typical engine components used in the test program. Furthermore, ASTM D1655 requirements are also achieved for all test conditions. Biofuel blends with less than 50% Jet A-1 are found to always be better than the biofuel blends with minimum of 50% Jet A-1 and, it is recommended to modify ASTM D1655 to include them as acceptable “drop-in” fuels.

Some Basic Studies of Liquid Propellant Injection Processes

1964 ◽  
Vol 68 (647) ◽  
pp. 743-750
Author(s):  
J. D. Lewis
Keyword(s):  
High Speed ◽  
Rocket Engine ◽  
Small Scale ◽  
Performance Measurements ◽  
Liquid Propellant ◽  
Controlling Parameter ◽  
Engine Combustion ◽  
The Subject ◽  
Basic Studies ◽  
Critical Combustion

SummaryThe recent analytical studies of rocket engine combustion based on propellant vaporisation as the rate controlling parameter, especially those by Spalding, and Priem and Heidmann, have contributed greatly to our appreciation of the mechanism of stable combustion. Critical combustion experiments on a small scale engine have shown fair agreement with vaporisation predictions, but have also revealed the need to understand and improve the mixing process.In parallel with performance measurements in a combustion system, detailed measurements of the atomisation process including the break-up mechanism and drop-size distribution have been made. However, there are many gaps in our knowledge of the subject and further work remains to be done.It is thought that the high-speed photographic and gas sampling techniques developed for these investigations provide useful research tools for more detailed studies of the problems.

Critical combustion diameter of condensed substances

1974 ◽  
Vol 10 (5) ◽  
pp. 580-587 ◽  
Author(s):  
B. N. Kondrikov ◽  
B. V. Novozhilov
Keyword(s):  
Combustion Diameter ◽  
Critical Combustion

Impact of Fuel Composition on Gas Turbine Engine Performance

2019 ◽  
Author(s):  
Dan Burnes ◽  
Alejandro Camou
Keyword(s):  
Gas Turbine ◽  
Carbon Emissions ◽  
Fossil Fuels ◽  
Engine Performance ◽  
Fuel Composition ◽  
Turbine Engine ◽  
Higher Power ◽  
Output Characteristics ◽  
Industrial Gas Turbine ◽  
Critical Combustion

Abstract An industrial gas turbine can run on a wide variety of fuels to produce power. Depending on the fuel composition and resulting properties, specifically the hydrogen-carbon ratio, the available output power, operability, and emissions of the engine can vary significantly. This study is an examination of how different fuels can affect the output characteristics of Solar Turbines Incorporated industrial engines, and highlights the benefits of using fuels with higher hydrogen-carbon ratios including higher power, higher efficiency, and lower carbon emissions. This study also highlights critical combustion operability issues that need to be considered such as autoignition, flashback, blowout and combustion instabilities that become more prominent when varying the hydrogen-carbon ratio significantly. Our intent is to provide a clear and concise reference to edify the reader examining attributes of fuels with different properties and how natural gas is superior to other fossil fuels with lower hydrogen carbon ratios in terms of carbon emissions, power, and efficiency.

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