skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


  • NSF Public Access
  • Search Results
  • Development of a Synthetic Surrogate for F-24 From Blends of Iso-Paraffinic Kerosene (IPK) and Fischer-Tropsch Synthetic Kerosene (S8) in a Constant Volume Combustion Chamber (CVCC)
Title: Development of a Synthetic Surrogate for F-24 From Blends of Iso-Paraffinic Kerosene (IPK) and Fischer-Tropsch Synthetic Kerosene (S8) in a Constant Volume Combustion Chamber (CVCC)
Investigations were conducted using mass blends of Iso-Paraffinic Kerosene (IPK) and Fischer-Tropsch Synthetic Kerosene (S8) to produce a synthetic surrogate for aerospace F-24. Due to the fossil fuel origin of F-24, the introduction of a synthetic surrogate would create a sustainable aviation fuel (SAF) with sources obtained from within the United States. An analysis of ignition delay (ID), combustion delay (CD), derived cetane number (DCN), negative temperature coefficient (NTC) region, Low-Temperature Heat Release region (LTHR) and High-Temperature Heat Release (HTHR) was conducted using a PAC CID 510 Constant Volume Combustion Chamber (CVCC). The fuels examined in this study are neat IPK, neat S8, neat F-24, and by mass percentages, as follows: 75IPK 25S8, 52IPK 48S8, 51IPK 49S8, 50IPK 50S8 and 25IPK 75S8. The DCN values determined for IPK, S8, and F-24 were 26.92, 59.56 and 44.35 respectively. The influence of IPK present in the blends increases CD, thus reducing the DCN significantly. The fuel blend of 50IPK 50S8 was observed to be the closest match to F-24 when comparing DCN, ID and CD. The surrogate blends were determined to have a lower magnitude of peak pressure ringing compared to that of the neat S8 and F-24, this is due to the extended NTC region caused by the IPK present in the blend. During further refinement of the surrogate blend, the Apparent Heat Release Rate (AHRR) curve for the 51IPK 49S8 fuel blend was found to have the closest match to the AHRR of F24. The surrogate blend 50IPK 50S8 was shown to have the smallest percent difference and best match during the LTHR stage, compared to F-24, while 52IPK 48S8 had the smallest percent difference for the energy released during LTHR. The ID and CD of the 25/75% blends were too dissimilar from the F-24 target to be considered as a surrogate. A Noise Vibration Harshness (NVH) analysis was also conducted during the combustion of the three neat fuels in the CVCC. This analysis was conducted to relate the ID, CD, HTHR and ringing to the vibrations that occur during combustion. Neat S8 was observed to have the most vibrations occurring during the combustion process. Additionally, the HTHR was observed to have a distinct pattern for the three neat fuels and the combustion of these fuels was quieter overall.  more » « less
Award ID(s):
1950207
PAR ID:
10414635
Author(s) / Creator(s):
; ; ; ; ; ;
Editor(s):
ASME
Date Published:
Journal Name:
Proc. ASME. ICEF2022, ASME 2022 ICE Forward Conference,
Volume:
V001T02A009
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. (, Proc. ASME. ICEF2021, ASME 2021 Internal Combustion Engine Division Fall Technical Conference,)
    ASME; iCEF (Ed.)
    Research was conducted to observe the correlation of ignition delay, combustion delay, the negative temperature coefficient region (NTCR), and the low temperature heat release region (LTHR), in a constant volume combustion chamber (CVCC) in relation to blended amounts of iso-paraffinic kerosene (IPK) by mass with Jet-A and their derived cetane numbers (DCN). The study utilizes the ASTM standard D7668-14.a in a PAC CID 510 CVCC. The DCN was calculated using the ignition delay and combustion delay measured over 15 combustion events. The fuel blends investigated were 75%Jet-A blended with 25%IPK, 50%Jet-A with 50%IPK, 25%Jet-A with 75%IPK, neat Jet-A, and neat IPK. The ignition delay of neat Jet-A and IPK was found to be 3.26ms and 5.31ms, respectively, and the combustion delay of the fuels were 5.00ms and 17.17 ms, respectively. The ignition delay for 75Jet-A25IPK, 50Jet-A50IPK, 25Jet-A75IPK, fuel blends were found to be 3.5ms, 3.8ms, and 4.2ms, respectively. The combustion delay between the 75Jet-A25IPK, 50Jet-A50IPK, 25Jet-A75IPK, blends are 5.8ms, 7.0ms, and 9.4ms, respectively. The DCNs for 75Jet-A25IPK, 50Jet-A50IPK, 25Jet-A75IPK 43.1, 38.7, and 33.5, respectively. The DCN of the fuel blends compared to neat Jet-A was lower by 10.16% for 75Jet-A25IPK, 19.37% for 50Jet-A50IPK, 30.50% for 25Jet-A75IPK and 46.03% for neat IPK. Blends with larger amounts by mass of IPK resulted in extended ignition and combustion delays. It is concluded that the fuels that have larger amounts of IPK blended within them have extended NTC regions, LTHR regions, and decreased ringing intensity during combustion. 
    more » « less
  2. ; ; ; ; (, Proceedings of ASME 2023 ICE Forward Conference)
    ASME (Ed.)
    An investigation was conducted on the performance and emissions characteristics of two Fischer-Tropsch (F-T) synthetic kerosenes, Gas-to-Liquid (GTL) S8 and Coal-to-Liquid (CTL) Iso-Paraffinic Kerosene (IPK), in a high compression ratio research engine with separate combustion chamber and using neat ULSD as a baseline. A 50% and a 70% by mass blend S8 with ULSD and a 50% and a 70% by mass blend of IPK with ULSD were analyzed for performance and emissions at 5, 6, and 7 bar Indicated Mean Effective Pressure (IMEP) and 2400 rpm. Additionally, neat S8, neat IPK, and neat ULSD were investigated in the Constant Volume Combustion Chamber (CVCC) for Ignition Delay (ID), Combustion Delay (CD), and Derived Cetane Number (DCN). S8 was found to have the highest DCN at 62 with very short ID and CD while IPK was found to have the lowest DCN at 26 and with the longest ID and CD. ULSD has a DCN between the two F-T fuels at 48. As a result of its long ID and CD, IPK showed extended regions of Low Temperature Heat Release (LTHR) and Negative Temperature Coefficient Region (NTCR) in the CVCC. It was also found that neat IPK, 50ULSD50IPK, and 30ULSD70IPK exhibit little to no ringing events at peak pressure and after High Temperature Heat Release (HTHR). In the research engine, peak heat release for ULSD, 50ULSD50S8, and 50ULSD50IPK was found to be 24.2 J/CAD, 20.5 J/CAD, and 23.4 J/CAD respectively. Due to the increase of the DCN with the addition of S8 to the blend, the 50ULSD50S8 blend exhibited minimal difference between the pre-chamber and the main chamber as it ignites earlier in the cycle with the flame front traveling quickly to the main chamber. IPK, however, had a short physical ignition delay and a long chemical ignition delay, as indicated by its low DCN, takes longer to ignite and creates a more homogeneous mixture in the highly turbulent pre-chamber. This causes a spike in heat release in the pre-chamber before the flame front propagates to the main chamber. This resulted in 50ULSD50IPK having the highest Peak Pressure Rise Rate (PPRR) and 50ULSD50S8 having the lowest PPRR. While both fuel blends reduced the soot emissions due to their low aromatic content, 50ULSD50IPK showed a 25% reduction in soot when compared to ULSD while 50ULSD50S8 showed only a 6% reduction in soot when compared to neat ULSD. There was a increase in CO emissions with the addition of IPK and a reduction in CO at low load with the addition of S8. With both F-T fuels, CO2 and NOx were found to decrease. 
    more » « less
  3. ; ; ; ; ; ; (, Proc. ASME. ICEF2022, ASME 2022 ICE Forward Conference,)
    ASME (Ed.)
    In this study, iso-paraffinic kerosene (IPK) was analyzed for ignition delay, combustion delay, pressure trace, pressure rise rate and, apparent heat release rate in an experimental single cylinder indirect injection (IDI) compression ignition engine as well as in a constant volume combustion chamber (CVCC). Neat IPK, neat ULSD, and a by-mass blend of 50%IPK50%ULSD were analyzed in a CVCC and an IDI engine to determine the effect of Derived Cetane Number (DCN), Ignition Delay (ID), and Low Temperature Heat Release (LTHR) on combustion timing and engine knock. In the CVCC, IPK was found to have a significantly lower DCN than ULSD at 26 and 47, respectively. The blend was found to have a DCN between the two neat fuels at 37.5. Additionally, the ignition delay increased in the CVCC from 3.56 ms for ULSD to 5.3 ms for IPK with the blend falling between the two at 4.38 ms. For engine research, the single-cylinder experimental IDI engine was run at 2400 rpm at 5, 6, and 7 Indicated Mean Effective Pressure (IMEP) using each of the three researched fuels. It was found that when running neat IPK, there was a profound level of engine knock at all loads characterized by the 60% increase in the Peak Pressure Rise Rate (PPRR) when compared to ULSD. The pressure trace for IPK at all loads showed a significant delay in combustion due to IPK’s resistance to autoignition. This was observed in the increasing ignition delay in the engine from 0.88 ms for ULSD to 1.1 ms at 7 bar IMEP for IPK. Despite the delay in ignition for IPK, all three researched fuels reached peak Apparent Heat Release Rate (AHRR) at approximately 370° leading to a much more rapid increase in AHRR for IPK when compared to ULSD. This steep slope in the AHRR, also seen in the increased PPRR, and longer ID caused the high levels of engine knock, observed as oscillations in the pressure trace which decreased in magnitude as IMEP increased. 
    more » « less
  4. ; ; ; ; ; (, SAE Technical Paper Series)
    The Coal-To-Liquid (CTL) synthetic aviation fuel, Iso-Paraffinic Kerosene (IPK), was studied for ignition delay, combustion delay, pressure trace, pressure rise rate, apparent heat release rate in an experimental single cylinder indirect injection (IDI) compression ignition engine and a constant volume combustion chamber (CVCC). Autoignition characteristics for neat IPK, neat Ultra-Low Sulfur Diesel (ULSD), and a blend of 50%IPK and 50% ULSD were determined in the CVCC and the effects of the autoignition quality of each fuel were determined also in an IDI engine. ULSD was found to have a Derived Cetane Number (DCN) of 47 for the batch used in this experimentation. IPK was found to have a DCN of 25.9 indicating that is has a lower affinity for autoignition, and the blend fell between the two at 37.5. Additionally, it was found that the ignition delay for IPK in the CVCC was 5.3 ms and ULSD was 3.56 ms. This increase in ignition delay allowed the accumulation of fuel in the combustion chamber when running with IPK that resulted in detonation of the premixed air and fuel found to cause high levels of Ringing Intensity (RI) when running neat IPK indicated by the 60% increase in Peak Pressure Rise Rate (PPRR) when compared to ULSD at the same load. An emissions analysis was conducted at 7 bar Indicated Mean Effective Pressure (IMEP) for ULSD and the blend of 50% ULSD and 50% IPK. With the addition of 50% IPK by mass, there was found to be a reduction in the NOx, CO2, with a slight increase in the CO in g/kWh. 
    more » « less
  5. ; ; ; ; ; (, SAE Transactions)
    SAE (Ed.)
    An investigation of the performance and emissions of a Fischer-Tropsch Coal-to-Liquid (CTL) Iso-Paraffinic Kerosene (IPK) was conducted using a CRDI compression ignition research engine with ULSD as a reference. Due to the low Derived Cetane Number (DCN), of IPK, an extended Ignition Delay (ID), and Combustion Delay (CD) were found for it, through experimentation in a Constant Volume Combustion Chamber (CVCC). Neat IPK was analyzed in a research engine at 4 bar Indicated Mean Effective Pressure (IMEP) at three injection timings: 15°, 20°, and 25° BTDC. Combustion phasing (CA50) was matched with ULSD at 10.8° and 16° BTDC. The IPK DCN was found to be 26, while the ULSD DCN was significantly higher at 47 in a PAC CID 510. In the engine, IPK’s DCN combined with its short physical ignition delay and long chemical ignition delay compared to ULSD, caused extended duration in Low Temperature Heat Release (LTHR) and cool flame formation. It was found in an analysis of the Apparent Heat Release Rate (AHRR) curve for IPK that there were multiple Negative Temperature Coefficient (NTCR) regions before the main combustion event. The High Temperature Heat Release (HTHR) of IPK achieved a greater peak heat release rate compared to ULSD. Pressure rise rate for IPK was observed to increase significantly with increase in injection timing. The peak in-cylinder pressure was also greater for IPK when matching CA50 by varying injection timing. Emissions analysis revealed that IPK produced less NOx, soot, and CO2 compared to ULSD. CO and UHC emissions for IPK increased. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Save / Share this Record
  • Send to Email