scholarly journals Advanced Combustion Technology Program

1989 ◽  
Keyword(s):  
Technology Program ◽  
Advanced Combustion ◽  
Combustion Technology

The NASA Broad-Specification Fuels Combustion Technology Program: An Assessment of Phase I Test Results

1983 ◽  
Author(s):  
James S. Fear
Keyword(s):  
Adverse Effects ◽  
Phase I ◽  
Phase Ii ◽  
Pollutant Emissions ◽  
Test Results ◽  
Combustion System ◽  
Technology Program ◽  
Advanced Combustion ◽  
Combustion Technology ◽  
Selection Of

An assessment is made of the results of phase I screening testing of current and advanced combustion system concepts using several broadened-properties fuels. The severity of each of several fuels-properties effects on combustor performance or liner life is discussed, as well as design techniques with the potential to offset these adverse effects. The selection of concepts to be pursued in Phase II refinement testing is described. This selection takes into account the relative costs and complexities of the concepts, the current outlook on pollutant emissions control, and practical operational problems.

Effect of EGR in a Gasoline Operated Diesel Engine in LTC Mode

2012 ◽  
Author(s):  
Stephen Ciatti ◽  
Swami Nathan Subramanian ◽  
Alison Ferris
Keyword(s):  
Power Density ◽  
Diesel Engines ◽  
High Efficiency ◽  
Cetane Number ◽  
Reference Points ◽  
Experimental Investigations ◽  
Boost Pressure ◽  
Oxides Of Nitrogen ◽  
Advanced Combustion ◽  
Combustion Technology

Conventional combustion techniques struggle to meet the current emissions’ regulations while retaining high engine efficiency. Specifically in automotive diesel engines, oxides of nitrogen (NOx) and particulate matter (PM) emissions have limited the utilization of diesel fuel in compression ignition engines. By comparison, throttled, knock-limited conventional gasoline operated SI engines tend not to be fuel efficient. Advanced combustion systems that simultaneously address PM and NOx while retaining the high efficiency of modern diesel engines, are being developed around the globe [1]. One of the most difficult problems in the area of advanced combustion technology development is the control of combustion initiation [2] and retaining power density [3]. During the past several years, significant progress has been accomplished in reducing emissions of NOx and PM through strategies such as LTC/HCCI/PCCI/PPCI and other advanced combustion processes; however control of ignition and improving power density has suffered to some degree — advanced combustion engines tend to be limited to the 10 bar BMEP range and under [4]. Experimental investigations have been carried out on a light duty, DI, multi cylinder, diesel automotive engine. The engine is operated in low temperature combustion technology with 87 RON (Research Octane Number) fuel [7]. Using an Ignition Quality Test (IQT) device, the equivalent Cetane Number (CN) was measured to be 25. In the present work, various EGR rates are examined to determine the effect on the combustion, emissions and performance. Experiments were conducted at three different engine load/speed combinations that are part of General Motors’ reference points for vehicle operation. To reduce the complexity, boost pressure and injection pressure and timing were kept constant while EGR percentage and intake temperature were used as parameters in this study. The intake temperature was not truly independent, as it trended with EGR level, but based upon the boost level and the available EGR cooling, Intake Air Temperature (IAT) was kept in the range of 40–80 deg C. Additional cooling capacity will be added in future work in an effort to keep IAT more consistent. EGR rates have a detrimental effect on engine efficiencies at lower load while it appears to have little effect on efficiency at higher loads. A more significant effect at very low load appears to be higher intake temperatures (hot EGR) as opposed to the very slight decrease in oxygen concentration.

scholarly journals Review on an Advanced Combustion Technology: Supercritical Hydrothermal Combustion

2020 ◽  
Vol 10 (5) ◽  
pp. 1645 ◽  
Author(s):  
Chengchao Cui ◽  
Yanhui Li ◽  
Shuzhong Wang ◽  
Mengmeng Ren ◽  
Chuang Yang ◽  
...  
Keyword(s):  
Heavy Oil ◽  
Batch Reactor ◽  
Industrial Applications ◽  
Thermal Recovery ◽  
Continuous Reactor ◽  
Ignition Process ◽  
Advanced Combustion ◽  
Wide Range ◽  
Homogeneous Combustion ◽  
Combustion Technology

Supercritical hydrothermal combustion, a new and promising homogeneous combustion technology with a wide range of application scenarios and broad development prospects, provides creative ideas and means for the enhanced degradation of organic wastes, hydrothermal spallation drilling, thermal recovery of heavy oil, etc. This technology is elaborated upon in five parts: (1) introducing the main devices including semi-batch reactor and continuous reactor to study the hydrothermal flame in accordance with research institutions, (2) presenting the research status of related numerical simulation from the angles of reaction kinetics and flow-reaction, (3) summarizing the characteristics of hydrothermal flame and combustion by five key parameters, (4) dividing up ignition process and explaining ignition mechanism from the perspectives of critical physical properties of water and heat transfer and mixing conditions, (5) discussing and forecasting its industrial applications including hydrothermal spallation drilling, the thermal recovery of heavy oil, the clean conversion and utilization of coal-based fuel, and the harmless treatment of pollutants. By and large, this paper analyzed in detail everything from experimental equipment to industrial applications, from combustion characteristics to ignition mechanisms, and from summary conclusions to prospect prediction. In the end, herein is summarized a couple of existing paramount scientific and technical obstacles in hydrothermal combustion. Further significant studies in the future should include excellent reactors, advanced monitoring techniques, and powerful computational fluid dynamics.

NASA/General Electric Broad-Specification Fuels Combustion Technology Program: Phase I

1983 ◽  
Vol 7 (6) ◽  
pp. 508-517 ◽  
Author(s):  
W. J. Dodds ◽  
E. E. Ekstedt ◽  
D. W. Bahr ◽  
J. S. Fear
Keyword(s):  
Phase I ◽  
General Electric ◽  
Technology Program ◽  
Combustion Technology

scholarly journals NASA Broad-Specification Fuels Combustion Technology Program: Status and Description

1980 ◽  
Author(s):  
J. S. Fear
Keyword(s):  
Gas Turbine ◽  
Jet Fuel ◽  
Full Scale ◽  
Fuel Properties ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Aircraft Engines ◽  
Technology Program ◽  
Current Specification ◽  
Combustion Technology

The use of “broad-specification” fuels in aircraft gas turbine engines can be a significant factor in offsetting anticipated shortages of current-specification jet fuel in the latter part of the century. The changes in fuel properties accompanying the use of broad-specification fuels will tend to cause numerous emissions, performance, and durability problems in currently-designed combustion systems. The NASA Broad-Specification Fuels Combustion Technology Program is a contracted effort to evolve and demonstrate the technology required to utilize broad-specification fuels in current and next generation commercial Conventional Takeoff and Landing (CTOL) aircraft engines, and to verify this technology in full-scale engine tests in 1983. The program consists of three phases: Combustor Concept Screening, Combustor Optimization Testing, and Engine Verification Testing.

An Experimental and Modeling Study of HCCI Combustion Using n-Heptane

2006 ◽  
Author(s):  
Hailin Li ◽  
Hongsheng Guo ◽  
W. Stuart Neill ◽  
Wally Chippior ◽  
Joshua D. Taylor
Keyword(s):  
Internal Combustion Engines ◽  
Combustion Process ◽  
Engine Performance ◽  
Strong Impact ◽  
Engine Operation ◽  
Hcci Combustion ◽  
Advanced Combustion ◽  
Auto Ignition ◽  
Combustion Technology ◽  
Modeling Study

Homogeneous Charge Compression Ignition (HCCI) is an advanced combustion technology being considered for internal combustion engines due to the potential for high fuel conversion efficiency and extremely low PM and NOx emissions. In principle, HCCI involves the auto-ignition of a homogeneous mixture of fuel, air and diluents at low to moderate temperatures and high pressure. Previous research has indicated that fuel chemistry has a strong impact on HCCI combustion. This paper reports the preliminary results of an experimental and modeling study of HCCI engine operation using n-heptane, which has a well known fuel chemistry. The experiments were designed to explore the effects of intake temperature, compression ratio, air/fuel ratio, engine speed and turbo-charging on HCCI combustion. A numerical model with detailed fuel chemistry was developed to simulate the combustion process in HCCI engines and predict engine performance. The model captured the main combustion stage and its variation in phasing with critical engine parameters.

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