TY - GEN
T1 - Transients of Shear-Layer Oscillation in Cavity Flow in Response to Unsteady Actuation
AU - Islam, Md Rashidul
AU - Sun, Yiyang
N1 - Publisher Copyright:
© 2023, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.
PY - 2023
Y1 - 2023
N2 - Controlling the shear-layer oscillation in open cavity flows through energy-based actuation remains a popular technique because of its flexibility in tackling different flow conditions. However, an efficient design of an unsteady actuation strategy is challenging due to our limited understanding of the transient dynamics induced by actuation on the shear-layer oscillation. In this work, we investigate the response of cavity flow oscillations to various unsteady actuation introduced upstream of the cavity leading edge by performing direct numerical simulations (DNS). The free-stream Mach number is M∞ = 0.5, and the depth-based Reynolds number is 925. Single- and multiple-cycle actuation in the wall-normal direction with varying duty cycles, amplitudes, and different actuation onset are studied. The signature of flow oscillation obtained from the probes in the shear layer and the cavity aft-wall reveals significant transient dynamics in response to the unsteady actuation. We note that the oscillation frequency and the limit cycle phase change due to the actuation. Moreover, we found two sensitive regions in the phase space of the limit cycle which can lead to either transient amplification or suppression in the shear layer oscillation. The multiple-cycle actuation reveals some unique frequencies and the number of pulses pair that can generate a prolonged suppression of the shear layer oscillation. Moreover, we found that the three-dimensional actuation has the same level of control authority as the two-dimensional actuation in controlling the shear-layer oscillation. The results suggest that it is possible to achieve distinct control objectives using the same actuator by adjusting the unsteady parameter values to generate a favorable response.
AB - Controlling the shear-layer oscillation in open cavity flows through energy-based actuation remains a popular technique because of its flexibility in tackling different flow conditions. However, an efficient design of an unsteady actuation strategy is challenging due to our limited understanding of the transient dynamics induced by actuation on the shear-layer oscillation. In this work, we investigate the response of cavity flow oscillations to various unsteady actuation introduced upstream of the cavity leading edge by performing direct numerical simulations (DNS). The free-stream Mach number is M∞ = 0.5, and the depth-based Reynolds number is 925. Single- and multiple-cycle actuation in the wall-normal direction with varying duty cycles, amplitudes, and different actuation onset are studied. The signature of flow oscillation obtained from the probes in the shear layer and the cavity aft-wall reveals significant transient dynamics in response to the unsteady actuation. We note that the oscillation frequency and the limit cycle phase change due to the actuation. Moreover, we found two sensitive regions in the phase space of the limit cycle which can lead to either transient amplification or suppression in the shear layer oscillation. The multiple-cycle actuation reveals some unique frequencies and the number of pulses pair that can generate a prolonged suppression of the shear layer oscillation. Moreover, we found that the three-dimensional actuation has the same level of control authority as the two-dimensional actuation in controlling the shear-layer oscillation. The results suggest that it is possible to achieve distinct control objectives using the same actuator by adjusting the unsteady parameter values to generate a favorable response.
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U2 - 10.2514/6.2023-3995
DO - 10.2514/6.2023-3995
M3 - Conference contribution
AN - SCOPUS:85200405762
SN - 9781624107047
T3 - AIAA Aviation and Aeronautics Forum and Exposition, AIAA AVIATION Forum 2023
BT - AIAA Aviation and Aeronautics Forum and Exposition, AIAA AVIATION Forum 2023
PB - American Institute of Aeronautics and Astronautics Inc, AIAA
T2 - AIAA Aviation and Aeronautics Forum and Exposition, AIAA AVIATION Forum 2023
Y2 - 12 June 2023 through 16 June 2023
ER -