PQIS Fuel Trends.

Transcription

1 Supporting Information for Influence of Jet Fuel Composition on Aircraft Engine Emissions: A Synthesis of Aerosol Emissions Data from the NASA APEX, AAFEX, and ACCESS Missions Richard H. Moore,,, Michael Shook,, Andreas Beyersdorf, Chelsea Corr,, Scott Herndon, W. Berk Knighton, Richard Miake-Lye, K. Lee Thornhill,, Edward L. Winstead,, Zhenhong Yu, Luke D. Ziemba, and Bruce E. Anderson NASA Langley Research Center, Hampton, VA 23681, USA, Science Systems and Applications, Inc. (SSAI), Hampton, VA, 23666, USA, NASA Postdoctoral Program, Oak Ridge Associated Universities, Oak Ridge, TN 3783, USA, Aerodyne Research, Inc., Billerica, MA 1821, USA., Montana State University, Bozeman, MT 59717, USA, and Science Systems and Applications, Hampton, VA 23666, USA richard.h.moore@nasa.gov PQIS Fuel Trends Defense Logistics Agency (DLA) Energy compiles an annual report describing fuel quantities and properties for United States Department of Defense fuel procurements as part of the Petroleum Quality Information System (PQIS). While not necessarily representative of the worldwide aviation fuel supply, the PQIS report is based on data obtained for over 1.6 billion gallons of JP-8 fuel in the continuous United States during, and similar volumes for prior years. Figure S1 shows the PQIS To whom correspondence should be addressed NASA Langley Research Center, Hampton, VA 23681, USA Science Systems and Applications, Inc. (SSAI), Hampton, VA, 23666, USA NASA Postdoctoral Program, Oak Ridge Associated Universities, Oak Ridge, TN 3783, USA Aerodyne Research, Inc., Billerica, MA 1821, USA. Montana State University, Bozeman, MT 59717, USA Science Systems and Applications, Hampton, VA 23666, USA trends in mean JP-8 fuel properties from 21- (top) and property histograms for the two most recent years (bottom). The overall trend in sulfur and aromatics over this time period is toward slightly lower values, naphthalene content has increased slightly, and hydrogen content has been fairly constant. As discussed in the main tet, the military specification for JP-8 fuel is fairly broad, and fuel sulfur content can range from -3 ppmm S, while aromatics cannot eceed 25% by volume to meet the specification. In reality, the fuel property ranges are much more narrow, with most fuels having lower than 1 ppmm S and aromatic content of 15-2% by volume. The JP-8 fuels obtained for the APEX, AAFEX, and ACCESS ground tests are consistent with this range. 1

2 Interactions Between Eplanatory Variables Figure S2 shows the collinearity between the eplanatory fuel property variables used in the multiple regression model. A high degree of multicollinearity is found between aromatic, napthalenes, and hydrogen content (i.e., the points are clustered closely to the linear fit line), while sulfur content varies less consistently with these variables. As discussed in the main tet, the engine thrust was initially set to a given fan speed (N1), but fluctuations in the ambient temperature can alter the fuel flow rate within a single thrust setting. This is shown in Figure S3. The mean fuel flow rate (dotted line) is used in the unstandardized regression analysis to ensure that this temperature dependence is reflected in the ambient temperature dependence coefficient rather than the flow flow rate coefficient. Summary of Dataset Files and Variables The test point data used in the statistical analyses are included as separate files detailed in Table S1. Each file contains the variables described in Table S2. References (1) PQIS, PQIS Annual Report;. 2

3 8 Sulfur (ppmm S) % of Total JP8 Fuel Volume Tested Naphthalene % of Total JP8 Fuel Volume Tested Hydrogen (mass%) Aromatics Year Fuel Sulfur Content (ppmm S) Fuel Naphthalene Content Fuel Hydrogen Content (mass%) Fuel Aromatic Content Figure S1: Timeseries of mean fuel properties (top) and single-year histograms (bottom) showing typical JP8 fuel characteristics reported by PQIS for the past decade 1. Linear trend lines are included in the time series plot to guide the eye. 3

4 Naphthalenes Aromatics 15 5 Sulfur (ppmm S) Hydrogen Content (mass%) 1 3 Temp. ( oc) Eng #2 = 1 Eng #3 = Figure S2: Scatter plots of the fuel property data during NASA APEX, AAFEX, and ACCESS. Each variable is plotted against all other variables on the ordinate (rows) and the abscissa (columns). The bar charts on the diagonal show the frequency distribution of the variable for the entire dataset. 4

5 -1 Single Engine Fuel Flow Rate (kg s ) Nominal Power Setting: 1% 85% 65% 3% 7% 4% Linear Fit Mean Value Ambient Temperature (ºC) Figure S3: Relationship between engine fuel flow rate and ambient temperature for a given engine throttle setting. Solid lines are a linear fit to the data, while the dotted lines are the mean fuel flow values reported in Table 2 of the main tet, which are used for the unstandardized multiple regression model. 5

6 Filename Table S1: List of data files included in the Supplementary Information.zip file.. power4.tt power7.tt power3.tt power65.tt power85.tt power1.tt power3to1.tt Description Engine, Fuel, and Emissions Properties at 4% Nominal Engine Power Engine, Fuel, and Emissions Properties at 7% Nominal Engine Power Engine, Fuel, and Emissions Properties at 3% Nominal Engine Power Engine, Fuel, and Emissions Properties at 65% Nominal Engine Power Engine, Fuel, and Emissions Properties at 85% Nominal Engine Power Engine, Fuel, and Emissions Properties at 1% Nominal Engine Power Consolidated Data for 3-1% Nominal Engine Powers NOTE: Fuel flow rates in the power3to1.tt file have been set to their mean values for this power setting to capture the temperature dependence of the fuel flow rate in the statistical analysis. This is described in the manuscript. Fuel flow rates in the other files are those recorded during each test point. 6

7 Variable Name Table S2: List of variables included within each data file.. Description ID Test Point Identifier Within Each Power Setting Mission Name of Ground Test Project npoints Number of Data Points Within the Test Point Engine DC-8 Engine Number (#2 = Left Inboard, #3 = Right Inboard) Fuel Name of Jet Fuel Sulfur Fuel Sulfur Content (ppmm S) Aromatics Fuel Aromatic Content Naph Fuel Naphthalenes Content Hydrogen Fuel Hydrogen Content TempC Ambient Temperature at the Ground Test Site (degrees Celsius) ColdEIn Total Aerosol Number Emissions Inde (kg-fuel -1 ) HotEIn Non-Volatile Aerosol Number Emissions Inde (kg-fuel -1 ) VolEIn Volatile Aerosol Number Emissions Inde (kg-fuel -1 ) mbc Optically-Derived Black Carbon Mass Emissions Inde (mg kg-fuel -1 ) ColdV Total Aerosol Volume Emissions Inde (mm 3 kg-fuel -1 ) HotV Non-Volatile Aerosol Volume Emissions Inde (mm 3 kg-fuel -1 ) VolV Volatile Aerosol Volume Emissions Inde (mm 3 kg-fuel -1 ) Org Fract Aerosol Organic Fraction SO4 Fract Aerosol SO4 Fraction morg Derived Aerosol Organic Mass Emissions Inde (mg kg-fuel -1 ) mso4 Derived Aerosol SO4 Mass Emissions Inde (mg kg-fuel -1 ) ColdGMD Total Aerosol Number Geometric Mean Diameter (nm) ColdVMD Total Aerosol Volume Geometric Mean Diameter (nm) HotGMD Non-Volatile Aerosol Number Geometric Mean Diameter (nm) HotVMD Non-Volatile Aerosol Volume Geometric Mean Diameter (nm) Engine2 Flag; Equals 1 for Engine #2 and for Engine #3 Engine3 Flag; Equals 1 for Engine #3 and for Engine #2 N1 Engine Fan Speed (%) N2 Engine Combustor Speed (%) EGT Engine Ehaust Gas Temperature ( K) FF Engine Fuel Flow Rate (kg-fuel s -1 ) 7