TY - GEN
T1 - Three-dimensional global stability on stuart vortex of free shear layer
AU - Yakeno, Aiko
AU - Hirota, Makoto
N1 - Funding Information:
This work is partially supported by Tohoku University Center for Gender Equality Promotion (TUMUG).
Publisher Copyright:
© Springer Nature Switzerland AG 2019.
PY - 2019
Y1 - 2019
N2 - Three-dimensional secondary global instability for the two-dimensional Stuart vortex of a free shear layer is investigated. That is in order to clarify an increase mechanism of the turbulence kinetic energy which is due to three-dimensional rib structure between rolls when the flow separation is achieved. We developed a program to compute the optimal transitional modes to amplify kinetic energy the most for the two-dimensional Stuart vortex base flow and compared the three-dimensional optimal growths for several Stuart vortex profiles, they correspond to which pulsation generates in downstream of a hump in DNS study. Results show that linear energy growth rate of turbulence component becomes large at the high-frequency case and small at the low-frequency case, that tendency does not correspond to which in DNS study. It implies that not only the linear growth but also nonlinear process should contribute to generate three-dimensional rib structure and increase turbulence energy.
AB - Three-dimensional secondary global instability for the two-dimensional Stuart vortex of a free shear layer is investigated. That is in order to clarify an increase mechanism of the turbulence kinetic energy which is due to three-dimensional rib structure between rolls when the flow separation is achieved. We developed a program to compute the optimal transitional modes to amplify kinetic energy the most for the two-dimensional Stuart vortex base flow and compared the three-dimensional optimal growths for several Stuart vortex profiles, they correspond to which pulsation generates in downstream of a hump in DNS study. Results show that linear energy growth rate of turbulence component becomes large at the high-frequency case and small at the low-frequency case, that tendency does not correspond to which in DNS study. It implies that not only the linear growth but also nonlinear process should contribute to generate three-dimensional rib structure and increase turbulence energy.
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U2 - 10.1007/978-3-030-22196-6_2
DO - 10.1007/978-3-030-22196-6_2
M3 - Conference contribution
AN - SCOPUS:85072824564
SN - 9783030221959
T3 - Springer Proceedings in Physics
SP - 9
EP - 13
BT - Progress in Turbulence VIII - Proceedings of the iTi Conference in Turbulence 2018
A2 - Örlü, Ramis
A2 - Talamelli, Alessandro
A2 - Peinke, Joachim
A2 - Oberlack, Martin
PB - Springer Science and Business Media, LLC
T2 - 8th iTi Conference on Turbulence, 2018
Y2 - 3 September 2018 through 7 September 2018
ER -