scholarly journals Measurement of Exhaust Emissions From Two J-58 Engines at Simulated Supersonic Cruise Flight Conditions

1976 ◽  
Author(s):  
J. D. Holdeman
Keyword(s):  
Carbon Monoxide ◽  
Power Level ◽  
Exhaust Emissions ◽  
Flight Speed ◽  
Hydrocarbon Emissions ◽  
Oxides Of Nitrogen ◽  
Test Conditions ◽  
Simulated High Altitude ◽  
Unburned Hydrocarbons ◽  
Cruise Flight

Emissions of total oxides of nitrogen, unburned hydrocarbons, carbon monoxide, and carbon dioxide from two J-58 afterburning turbojet engines at simulated high-altitude flight conditions are reported. Test conditions included flight speeds from Mach 2 to 3 at altitudes from 16 to 23 km. For each flight condition, exhaust measurements were made for four or five power levels from maximum power without afterburning through maximum afterburning. The data show that exhaust emissions vary with flight speed, altitude, power level, and radial position across the exhaust. Oxides of nitrogen (NOx) emissions decreased with increasing altitude and increased with increasing flight speed. NOx emission indices with afterburning were less than half the value without afterburning. Carbon monoxide and hydrocarbon emissions increased with increasing altitude and decreased with increasing flight speed. Emissions of these species were substantially higher with afterburning than without.

S. I. Engine Pollution Control Using Low-Cost Palletized Catalytic Converter

Volume 2 ◽  
2004 ◽  
Author(s):  
Madhuri Jakkaraju ◽  
Vasudha Patri
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Pollution Control ◽  
Noble Metals ◽  
Fossil Fuel ◽  
Catalytic Converter ◽  
Low Cost ◽  
Hydrocarbon Emissions ◽  
Oxides Of Nitrogen ◽  
Carbon Dioxide Co2

I. C. Engines consume large amounts of fossil fuel emitting harmful pollutants like carbon monoxide (CO), unburnt hydrocarbons (UBHC), and oxides of nitrogen (NOx). By using a catalytic converter (CC), the carbon monoxide, hydrocarbon emissions can be transformed into less harmful carbon dioxide (CO2) & water vapor (H2O). Currently available CC’s are using costly noble metals like platinum (pt), palladium (pd), rhodium (rh) etc., hence making them expensive. This paper deals with the use of low-cost palletized silver coated alumina as the catalyst element in a CC. In this study, alumina and silver were used in the ratio of 10:1. All tests have been conducted on a stationary S.I. Engine at a constant speed of 1500 r.p.m with and without CC. Also, the performance of the palletized CC in combination with promoters like Bismuth, Cerium and Lanthanum was tested which have shown better results than silver alone as the coating element. It has been experimentally determined that the CO emissions have dropped from 7.25 (% vol) to 3.03(% vol) and the HC values have reduced from 350 ppm to 190 ppm.

scholarly journals Modification of Combustor Stoichiometry Distribution for Reduced NOx Emission From Aircraft Engines

1992 ◽  
Author(s):  
G. J. Sturgess ◽  
R. McKinney ◽  
S. Morford
Keyword(s):  
Fluid Dynamics ◽  
Carbon Monoxide ◽  
Emissions Reduction ◽  
Outlet Temperature ◽  
Aircraft Engines ◽  
Oxides Of Nitrogen ◽  
Design Chart ◽  
Temperature Distributions ◽  
Unburned Hydrocarbons ◽  
Reduction Of Oxides

Measurements of the emissions from an experimental engine were analyzed to construct a design chart for the reduction of oxides of nitrogen (NOx) in conventional combustors. The design chart was used to reconfigure the stoichiometry distribution of the combustor of a production engine so as to reduce NOx while holding the emissions of carbon monoxide, unburned hydrocarbons and smoke well below existing regulations. Combustion section pressure loss and combustor outlet temperature distributions were substantially unchanged. The modified design was refined with the aid of computational fluid dynamics calculations to optimize the emissions reduction. Worthwhile reductions in NOx were obtained with combustor modifications that are transparent to the engine user.

Correlation Between Speciated Hydrocarbon Emissions and Flame Ionization Detector Response for Gasoline/Alcohol Blends

2011 ◽  
Vol 133 (8) ◽  
Author(s):  
Thomas Wallner
Keyword(s):  
Exhaust Emissions ◽  
Flame Ionization Detector ◽  
Detector Response ◽  
Hydrocarbon Emissions ◽  
Response Factor ◽  
Oxides Of Nitrogen ◽  
Ionization Detector ◽  
Flame Ionization ◽  
Certification Testing ◽  
Exhaust Stream

The U.S. renewable fuel standard has made it a requirement to increase the production of ethanol and advanced biofuels to 36 billion by 2022. Ethanol will be capped at 15 billion, which leaves 21 billion to come from other sources such as butanol. Butanol has a higher energy density and lower affinity for water than ethanol. Moreover, alcohol fueled engines in general have been shown to positively affect engine-out emissions of oxides of nitrogen and carbon monoxide compared with their gasoline fueled counterparts. In light of these developments, the variety and blend levels of oxygenated constituents is likely to increase in the foreseeable future. The effect on engine-out emissions for total hydrocarbons is less clear due to the relative insensitivity of the flame ionization detector (FID) toward alcohols and aldehydes. It is well documented that hydrocarbon (HC) measurement using a conventional FID in the presence of oxygenates in the engine exhaust stream can lead to a misinterpretation of HC emissions trends for alcohol fuel blends. Characterization of the exhaust stream for all expected hydrocarbon constituents is required to accurately determine the actual concentration of unburned fuel components in the exhaust. In addition to a conventional exhaust emissions bench, this characterization requires supplementary instrumentation capable of hydrocarbon speciation and response factor independent quantification. Although required for certification testing, this sort of instrumentation is not yet widely available in engine development facilities. Therefore, an attempt is made to empirically determine FID correction factors for oxygenate fuels. Exhaust emissions of an engine fueled with several blends of gasoline and ethanol, n-butanol and iso-Butanol were characterized using both a conventional FID and a Fourier transform infrared. Based on these results, a response factor predicting the actual hydrocarbon emissions based solely on FID results as a function of alcohol type and content is presented. Finally, the correlation derived from data presented in this study is compared with equations and results found in the literature.

Premixing and Flash Vaporization in a Two-Stage Combustor

1982 ◽  
Vol 104 (1) ◽  
pp. 36-43 ◽  
Author(s):  
B. G. A. Sjo¨blom
Keyword(s):  
Carbon Monoxide ◽  
Combustion Zone ◽  
Recirculation Zone ◽  
Oxides Of Nitrogen ◽  
Two Stage ◽  
Fuel Flow ◽  
Secondary Fuel ◽  
Unburned Hydrocarbons ◽  
Complete Vaporization ◽  
Engine Power

A double recirculation zone two-stage combustor fitted with airblast atomizers has been investigated in a previous work. The present paper describes further tests with premixing tubes in the secondary combustion zone. Flash vaporization was employed to ensure complete vaporization of the secondary fuel, which was heated to 600K by the combustor inlet air. The combustor was run at conditions corresponding to four different engine power settings, and the effect of primary/secondary fuel flow split on emissions was investigated. Tests were also performed with unheated secondary fuel, and comparisons were made with flash vaporization data. The best configuration reduced the oxides of nitrogen by 54 percent, carbon monoxide by 59 percent and unburned hydrocarbons by 97 percent as compared to emission levels for the standard JT8D combustor, which was used as a reference.

scholarly journals Fuel Effects on Aircraft Combustor Emissions

1986 ◽  
Author(s):  
Curtis M. Reeves ◽  
Arthur H. Lefebvre
Keyword(s):  
Experimental Data ◽  
Carbon Monoxide ◽  
Fuel Injection ◽  
Injection Pressure ◽  
Operating Conditions ◽  
Pollutant Emissions ◽  
Design Parameters ◽  
Oxides Of Nitrogen ◽  
Fuel Type ◽  
Unburned Hydrocarbons

Results of an analytical program to determine the effects of broad variations in fuel properties on the pollutant emissions generated by several prominent turbojet engine combustion systems, including both tubo-annular and annular configurations, are presented. Measurements of mean drop size conducted at representative engine operating conditions are used to supplement the available experimental data on the effects of combustor design parameters, combustor operating conditions, and fuel type, on pollutant emissions. The results of the study indicate that the fuel’s physical properties that govern atomization quality and evaporation rates have a significant effect on the emissions of carbon monoxide and unburned hydrocarbons. Analysis of the available experimental data shows that the influence of fuel chemistry on the emissions of carbon monoxide, unburned hydrocarbons, and oxides of nitrogen, is small. Smoke emissions are found to be strongly dependent on combustion pressure, primary-zone fuel/air ratio, and the mode of fuel injection (pressure atomization or airblast). Fuel chemistry, as indicated by hydrogen content, is also important. Equations are presented for the correlation and/or prediction of exhaust emissions in terms of combustor size, combustor geometry, engine operating conditions, fuel spray characteristics, and fuel type.

Emission Reductions Through Precombustion Chamber Design in a Natural Gas, Lean Burn Engine

1992 ◽  
Vol 114 (3) ◽  
pp. 466-474 ◽  
Author(s):  
M. E. Crane ◽  
S. R. King
Keyword(s):  
Natural Gas ◽  
Exhaust Emissions ◽  
Hydrocarbon Emissions ◽  
Oxides Of Nitrogen ◽  
Lean Burn ◽  
Precombustion Chamber ◽  
Engine Efficiency ◽  
Chamber Design ◽  
And Control ◽  
Total Hydrocarbons

A study was conducted to evaluate the effects of various precombustion chamber design, operating, and control parameters on the exhaust emissions of a natural gas engine. Analysis of the results showed that engine-out total hydrocarbons and oxides of nitrogen (NOx) can be reduced, relative to conventional methods, through prechamber design. More specifically, a novel staged prechamber yielded significant reductions in NOx and total hydrocarbon emissions by promoting stable prechamber and main chamber ignition under fuel-lean conditions. Precise fuel control was also critical when balancing low emissions and engine efficiency (i.e., fuel economy). The purpose of this paper is to identify and explain positive and deleterious effects of natural gas prechamber design on exhaust emissions.

Correlation Between Speciated Hydrocarbon Emissions and Flame Ionization Detector Response for Gasoline/Alcohol Blends

2010 ◽  
Author(s):  
Thomas Wallner
Keyword(s):  
Exhaust Emissions ◽  
Flame Ionization Detector ◽  
Detector Response ◽  
Hydrocarbon Emissions ◽  
Response Factor ◽  
Oxides Of Nitrogen ◽  
Ionization Detector ◽  
Flame Ionization ◽  
Certification Testing ◽  
Exhaust Stream

The U.S. Renewable Fuel Standard has made it a requirement to increase the production of ethanol and advanced biofuels to 36 billion gallons by 2022. Ethanol will be capped at 15 billion gallons, which leaves 21 billion gallons to come from other sources, such as butanol. Butanol has a higher energy density and lower affinity for water than ethanol. Moreover, alcohol fueled engines in general have been shown to positively affect engine-out emissions of oxides of nitrogen and carbon monoxide compared to their gasoline fueled counterparts. In light of these developments the variety and blend levels of oxygenated constituents is likely to increase in the foreseeable future. The effect on engine-out emissions for total hydrocarbons (THC) is less clear due to the relative insensitivity of the flame ionization detector (FID) toward alcohols and aldehydes. It is well documented that hydrocarbon (HC) measurement using a conventional FID in presence of oxygenates in the engine exhaust stream can lead to a misinterpretation of HC emissions trends for alcohol fuel blends. Characterization of the exhaust stream for all expected hydrocarbon constituents is required to accurately determine the actual concentration of unburned fuel components in the exhaust. In addition to a conventional exhaust emissions bench, this characterization requires supplementary instrumentation capable of hydrocarbon speciation and response factor independent quantification. Although required for certification testing, this sort of instrumentation is not yet widely available in engine development facilities. Therefore an attempt is made to empirically determine an oxygenate fuel, FID correction factor. Exhaust emissions of an engine fueled with several blends of gasoline and ethanol, n-Butanol and iso-Butanol were characterized using both a conventional FID and an FTIR. Based on these results, a response factor predicting the actual hydrocarbon emissions, based solely on FID results as a function of alcohol type and content, is presented. Finally the correlation derived from data presented in this study is compared to equations and results found in the literature.

Modification of Combustor Stoichiometry Distribution for Reduced NOx Emission From Aircraft Engines

1993 ◽  
Vol 115 (3) ◽  
pp. 570-580 ◽  
Author(s):  
G. J. Sturgess ◽  
R. G. McKinney ◽  
S. A. Morford
Keyword(s):  
Fluid Dynamics ◽  
Carbon Monoxide ◽  
Emissions Reduction ◽  
Outlet Temperature ◽  
Aircraft Engines ◽  
Oxides Of Nitrogen ◽  
Design Chart ◽  
Temperature Distributions ◽  
Unburned Hydrocarbons ◽  
Reduction Of Oxides

Measurements of the emissions from an experimental engine were analyzed to construct a design chart for the reduction of oxides of nitrogen (NOx) in conventional combustors. The design chart was used to reconfigure the stoichiometry distribution of the combustor of a production engine so as to reduce NOx while holding the emissions of carbon monoxide, unburned hydrocarbons, and smoke well below existing regulations. Combustion section pressure loss and combustor outlet temperature distributions were substantially unchanged. The modified design was refined with the aid of computational fluid dynamics calculations to optimize the emissions reduction. Worthwhile reductions in NOx were obtained with combustor modifications that are transparent to the engine user.

Effects of Ethanol and/or Methanol in Alcohol-Gasoline Blends on Exhaust Emissions

1989 ◽  
Vol 111 (3) ◽  
pp. 432-438 ◽  
Author(s):  
R. M. Bata ◽  
V. P. Roan
Keyword(s):  
Carbon Monoxide ◽  
Exhaust Emissions ◽  
Hydrocarbon Emissions ◽  
Exhaust Gas ◽  
Alcohol Content ◽  
Hydrocarbon Production ◽  
Fuel Blends ◽  
Spark Timing ◽  
Exhaust Gas Emissions ◽  
Automotive Fuels

The effect on exhaust gas emissions (carbon monoxide, CO, hydrocarbons, HC, and aldehydes, CHO) resulting from mixing methanol and/or ethanol with gasoline for automotive fuels has been studied experimentally. Tests were conducted on an OEM four-cylinder engine running at different conditions of equivalence ratio and spark timing. Fuel blends with different percentages of alcohol content and different ratios of methanol to ethanol in the alcohol mixture were tested. Results of this investigation indicated that the presence of either or both of the alcohols in fuel blends significantly reduced the concentration of carbon monoxide in the exhaust emissions (up to 40–50 percent compared to pure gasoline only), with methanol slightly more effective than ethanol. Hydrocarbon emissions were also decreased by increasing the alcohol content of the fuel, with minimum hydrocarbon production occurring at percent alcohol-gasoline blends in conjunction with near-stoichiometric air-fuel ratios. However, aldehyde emissions were found to be markedly higher with alcohol-gasoline blends. The 10 percent alcohol-gasoline blends were found to produce about 50 percent more aldehyde emissions than pure gasoline.

scholarly journals Ultra-Lean Combustion at High Inlet Temperatures

1981 ◽  
Author(s):  
D. N. Anderson
Keyword(s):  
Carbon Monoxide ◽  
Turbine Engines ◽  
Residence Times ◽  
Gas Turbine Engines ◽  
Fuel Injector ◽  
Lean Combustion ◽  
Hot Environment ◽  
Test Conditions ◽  
Air Temperatures ◽  
Unburned Hydrocarbons

Combustion at inlet-air temperatures of 1100 to 1250 K was studied for application to advanced automotive gas turbine engines. Combustion was initiated by the hot environment, and therefore no external ignition source was used. Combustion was stabilized without a flameholder. The tests were performed in a 12-cm-diameter test section at a pressure of 2.5 × 105 Pa, with reference velocities of 32 to 60 m/s and at maximum combustion temperatures of 1350 to 1850 K. Number 2 diesel fuel was injected by means of a multiple-source fuel injector. Unburned hydrocarbons emissions were negligible for all test conditions. Nitrogen oxides emissions were less than 1.9 g NO2/kg fuel for combustion temperatures below 1680 K. Carbon monoxide emissions were less than 16 g CO/kg fuel for combustion temperatures greater than 1600 K, inlet-air temperatures higher than 1150 K, and residence times greater than 4.3 ms.

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