TY - JOUR
T1 - Dense core response to forced acoustic fields in oxygen-hydrogen rocket flames
AU - Morii, Youhi
AU - Beinke, Scott
AU - Hardi, Justin
AU - Shimizu, Taro
AU - Kawashima, Hideto
AU - Oschwald, Michael
N1 - Funding Information:
The experimental data were gathered with the assistance of Dmitry Suslov, Walter Clauβ, and the crew of the P8 test bench. This work was performed in the frame of the Franco-German Rocket Engine Stability iniTiative (REST), and the DLR-JAXA Joint Research Agreement on liquid propellant space propulsion. Research undertaken for this report has been assisted with a grant from the Sir Ross and Sir Keith Smith Fund (Smith Fund) ( www.smithfund.org.au ). The support is acknowledged and greatly appreciated. The Smith Fund by providing funding for this project does not verify the accuracy of any findings or any representations contained in it. Any reliance on the findings in any written report or information provided to you should be based solely on your own assessment and conclusions. The Smith fund does not accept any responsibility or liability from any person, company or entity that may have relied on any written report or representations contained in this report if that person, company or entity suffers any loss (financial or otherwise) as a result.
Funding Information:
The experimental data were gathered with the assistance of Dmitry Suslov, Walter Clau?, and the crew of the P8 test bench. This work was performed in the frame of the Franco-German Rocket Engine Stability iniTiative (REST), and the DLR-JAXA Joint Research Agreement on liquid propellant space propulsion. Research undertaken for this report has been assisted with a grant from the Sir Ross and Sir Keith Smith Fund (Smith Fund) (www.smithfund.org.au). The support is acknowledged and greatly appreciated. The Smith Fund by providing funding for this project does not verify the accuracy of any findings or any representations contained in it. Any reliance on the findings in any written report or information provided to you should be based solely on your own assessment and conclusions. The Smith fund does not accept any responsibility or liability from any person, company or entity that may have relied on any written report or representations contained in this report if that person, company or entity suffers any loss (financial or otherwise) as a result.
Publisher Copyright:
© 2020 Beihang University
PY - 2020/9
Y1 - 2020/9
N2 - Oscillatory combustion representative of thermo-acoustic instability in liquid rockets is simulated by experiment and LES calculation to investigate the flame behavior in detail. In particular, we focus on how the velocity and pressure fluctuations affect the behavior of the dense oxygen jet, or ‘LOx core’. The test case investigated is a high pressure, multi-injector, oxygen-hydrogen combustor with a siren for acoustic excitation. First, the LES calculation is validated by the resonant frequencies and average flame topology. A precise frequency correction is conducted to compare experiment with LES. Then an unforced case, a pressure fluctuation case, and a velocity fluctuation case are investigated. LES can quantitatively reproduce the LOx core shortening and flattening that occurs under transverse velocity excitation as it is observed in the experiments. On the other hand, the core behavior under pressure excitation is almost equal to the unforced case, and little shortening of the core occurs. The LOx core flattening is explained by the pressure drop around an elliptical cylinder using the unsteady Bernoulli equation. Finally, it is shown that the shortening of the LOx core occurs because the flattening enhances combustion by mixing and increase of the flame surface area.
AB - Oscillatory combustion representative of thermo-acoustic instability in liquid rockets is simulated by experiment and LES calculation to investigate the flame behavior in detail. In particular, we focus on how the velocity and pressure fluctuations affect the behavior of the dense oxygen jet, or ‘LOx core’. The test case investigated is a high pressure, multi-injector, oxygen-hydrogen combustor with a siren for acoustic excitation. First, the LES calculation is validated by the resonant frequencies and average flame topology. A precise frequency correction is conducted to compare experiment with LES. Then an unforced case, a pressure fluctuation case, and a velocity fluctuation case are investigated. LES can quantitatively reproduce the LOx core shortening and flattening that occurs under transverse velocity excitation as it is observed in the experiments. On the other hand, the core behavior under pressure excitation is almost equal to the unforced case, and little shortening of the core occurs. The LOx core flattening is explained by the pressure drop around an elliptical cylinder using the unsteady Bernoulli equation. Finally, it is shown that the shortening of the LOx core occurs because the flattening enhances combustion by mixing and increase of the flame surface area.
KW - Combustion instability
KW - Computational fluid dynamics (CFD)
KW - Large eddy simulation (LES)
KW - Liquid rocket engine
KW - Supercritical fluid
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U2 - 10.1016/j.jppr.2020.06.001
DO - 10.1016/j.jppr.2020.06.001
M3 - Article
AN - SCOPUS:85091246212
VL - 9
SP - 197
EP - 215
JO - Propulsion and Power Research
JF - Propulsion and Power Research
SN - 2212-540X
IS - 3
ER -