TY - JOUR
T1 - Experimental study of the structure of forward-tilting rotating detonation waves and highly maintained combustion chamber pressure in a disk-shaped combustor
AU - Nakagami, Soma
AU - Matsuoka, Ken
AU - Kasahara, Jiro
AU - Matsuo, Akiko
AU - Funaki, Ikkoh
N1 - Funding Information:
This study was subsidized by a Grant-in-Aid for Scientific Research (A), no. 24246137. The authors would like to thank the Japan Aerospace Exploration Agency. The authors would also like to thank all members of the "Research and Development of an Ultra-High-Thermal-Efficiency Rotating Detonation Engine with Self-Compression Mechanism," program team, which is being conducted as part of the Advanced Research Program for Energy and Environmental Technologies, New Energy and Industrial Technology Development Organization.
PY - 2017
Y1 - 2017
N2 - The structure of detonation waves in rotating detonation combustors (RDCs) and their combustion chamber pressure characteristics have not yet been fully clarified due to the complexity and shape of the RDC combustion chamber. Therefore, a disk-shaped RDC was used in this study to visualize the inside of the combustion chamber while simultaneously measuring its pressure. Forward-tilting rotating detonation waves were observed, and a schematic was proposed for them. The initial velocity of the forward-tilting rotating detonation wave was 1200 ± 160 m/s, and it subsequently increased to 1600 ± 160 m/s; meanwhile, the Chapman-Jouguet (CJ) velocity was 2376 m/s. There are several reasons why the velocity may have differed so widely from the CJ value, including the presence of burned gas in front of the detonation wave, the complicated wave structure due to non-uniformity of the mixture in the RDC, insufficient propellant mixing, and the difference between the true and actual wave propagation direction. The velocity and amplitude of the combustion chamber static pressure appeared to be correlated. Averaged combustion chamber static pressure reached 0.432 MPa, which was 89.0% and 92.8% of the fuel and oxidizer plenum pressure, respectively. Dynamic pressure was also estimated using an equilibrium calculation. The resulting dynamic pressure was 0.008 MPa, and estimated total pressure was 0.440 MPa; these values were 90.1% and 94.6% of the fuel and oxidizer plenum total pressure, respectively, even though pressure was lost through the small diameter injector holes.
AB - The structure of detonation waves in rotating detonation combustors (RDCs) and their combustion chamber pressure characteristics have not yet been fully clarified due to the complexity and shape of the RDC combustion chamber. Therefore, a disk-shaped RDC was used in this study to visualize the inside of the combustion chamber while simultaneously measuring its pressure. Forward-tilting rotating detonation waves were observed, and a schematic was proposed for them. The initial velocity of the forward-tilting rotating detonation wave was 1200 ± 160 m/s, and it subsequently increased to 1600 ± 160 m/s; meanwhile, the Chapman-Jouguet (CJ) velocity was 2376 m/s. There are several reasons why the velocity may have differed so widely from the CJ value, including the presence of burned gas in front of the detonation wave, the complicated wave structure due to non-uniformity of the mixture in the RDC, insufficient propellant mixing, and the difference between the true and actual wave propagation direction. The velocity and amplitude of the combustion chamber static pressure appeared to be correlated. Averaged combustion chamber static pressure reached 0.432 MPa, which was 89.0% and 92.8% of the fuel and oxidizer plenum pressure, respectively. Dynamic pressure was also estimated using an equilibrium calculation. The resulting dynamic pressure was 0.008 MPa, and estimated total pressure was 0.440 MPa; these values were 90.1% and 94.6% of the fuel and oxidizer plenum total pressure, respectively, even though pressure was lost through the small diameter injector holes.
KW - Pressure gain combustion
KW - RDC
KW - RDE
KW - Rotating detonation combustor
KW - Rotating detonation engine
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U2 - 10.1016/j.proci.2016.07.097
DO - 10.1016/j.proci.2016.07.097
M3 - Article
AN - SCOPUS:85006802969
VL - 36
SP - 2673
EP - 2680
JO - Proceedings of the Combustion Institute
JF - Proceedings of the Combustion Institute
SN - 1540-7489
IS - 2
ER -