TY - JOUR
T1 - Mixing characteristics of cracked gaseous hydrocarbon fuels in a scramjet combustor
AU - Ravindran, Magesh
AU - Bricalli, Mathew
AU - Pudsey, Adrian
AU - Ogawa, Hideaki
N1 - Funding Information:
The authors would like to gratefully acknowledge the support of the CRC-P50510 Hydrocarbon Fuel Technology for Hypersonic Air Breathing Vehicles, as well as the high-performance computing support from the National Computational Infrastructure Australia . The CRC Programme supports industry-led collaborations between industry, researchers and the community. The first author is also thankful for the support of the Australian Government Research Training Program (RTP) Scholarship and Candler's group at the University of Minnesota for the US3D code .
Publisher Copyright:
© 2019 IAA
Copyright:
Copyright 2019 Elsevier B.V., All rights reserved.
PY - 2019/9
Y1 - 2019/9
N2 - High-performance hydrocarbon-fuelled scramjet engines require efficient fuel-air mixing due to the relatively short flow residence time through the combustor. At high temperatures, hydrocarbon fuels react endothermically and absorb thermal energy from the surroundings. The process known as cracking becomes essential at high Mach numbers to increase the total heat-sink capacity of the fuel. This study presents the results of chemically frozen numerical simulations that investigate the mixing characteristics of cracked gaseous heavy hydrocarbon fuels injected through a circular, flush-wall porthole injector. The mixing characteristics of fuel compositions representing cracking efficiencies ranging from 0 to 100% are investigated. The mixing rates and flow structures are found to change with fuel compositions. As the cracking increases, the mixing and streamwise circulation increase for an injectant. However, the jet penetration and stagnation pressure losses decrease. The streamwise circulation is found to have a strong influence on the mixing, the injection pressure on the jet penetration and the strength of the bow shock on stagnation pressure losses. Overall, it is shown that there are mixing benefits to be gained by injecting cracked hydrocarbon fuels compared to heavy uncracked fuels in scramjets.
AB - High-performance hydrocarbon-fuelled scramjet engines require efficient fuel-air mixing due to the relatively short flow residence time through the combustor. At high temperatures, hydrocarbon fuels react endothermically and absorb thermal energy from the surroundings. The process known as cracking becomes essential at high Mach numbers to increase the total heat-sink capacity of the fuel. This study presents the results of chemically frozen numerical simulations that investigate the mixing characteristics of cracked gaseous heavy hydrocarbon fuels injected through a circular, flush-wall porthole injector. The mixing characteristics of fuel compositions representing cracking efficiencies ranging from 0 to 100% are investigated. The mixing rates and flow structures are found to change with fuel compositions. As the cracking increases, the mixing and streamwise circulation increase for an injectant. However, the jet penetration and stagnation pressure losses decrease. The streamwise circulation is found to have a strong influence on the mixing, the injection pressure on the jet penetration and the strength of the bow shock on stagnation pressure losses. Overall, it is shown that there are mixing benefits to be gained by injecting cracked hydrocarbon fuels compared to heavy uncracked fuels in scramjets.
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U2 - 10.1016/j.actaastro.2019.06.010
DO - 10.1016/j.actaastro.2019.06.010
M3 - Article
AN - SCOPUS:85067299827
SN - 0094-5765
VL - 162
SP - 168
EP - 184
JO - Acta Astronautica
JF - Acta Astronautica
ER -