TY - GEN
T1 - Effect of fineness ratio of 0.5 - 2.0 on the wake structure around a circular cylinder measured using time-resolved PIV
AU - Yokota, Sho
AU - Ochiai, Taku
AU - Ambo, Takumi
AU - Ozawa, Yuta
AU - Nonomura, Taku
AU - Asai, Keisuke
PY - 2019/1/1
Y1 - 2019/1/1
N2 - In this study, the wake structure around freestream-aligned cylinder is investigated and its aerodynamic characteristics are discussed. A magnetic suspension and balance system (MSBS) was used to support a model without interference from a mechanical support device. Seven models with the fineness ratio (length to diameter, L/D) of 0.5, 1.0, 1.25, 1.5, 1.75, 2.0, and 2.25 were used. Reynolds number based on the cylinder diameter were and . 3.2 × 104 6.3 × 104 The velocity field was obtained by particle image velocimetry (PIV) in the center plane of the cylinder. In the case of fineness ratio over 1.5, the reattachment of shear layer was observed from the mean velocity field. The characteristic fluctuation of velocity was confirmed in power spectral density of streamwise component and vertical component. The length of the recirculation region is different depending on fineness ratio. The characteristic frequencies of the velocity fluctuation which seems to be due to recirculation bubble pumping and large-scale structure are observed from power spectrum density.
AB - In this study, the wake structure around freestream-aligned cylinder is investigated and its aerodynamic characteristics are discussed. A magnetic suspension and balance system (MSBS) was used to support a model without interference from a mechanical support device. Seven models with the fineness ratio (length to diameter, L/D) of 0.5, 1.0, 1.25, 1.5, 1.75, 2.0, and 2.25 were used. Reynolds number based on the cylinder diameter were and . 3.2 × 104 6.3 × 104 The velocity field was obtained by particle image velocimetry (PIV) in the center plane of the cylinder. In the case of fineness ratio over 1.5, the reattachment of shear layer was observed from the mean velocity field. The characteristic fluctuation of velocity was confirmed in power spectral density of streamwise component and vertical component. The length of the recirculation region is different depending on fineness ratio. The characteristic frequencies of the velocity fluctuation which seems to be due to recirculation bubble pumping and large-scale structure are observed from power spectrum density.
KW - Bluff body
KW - Cylinder
KW - Flow visualization
KW - MSBS
KW - Wake structure
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U2 - 10.1115/AJKFluids2019-5530
DO - 10.1115/AJKFluids2019-5530
M3 - Conference contribution
AN - SCOPUS:85076407374
T3 - ASME-JSME-KSME 2019 8th Joint Fluids Engineering Conference, AJKFluids 2019
BT - Fluid Mechanics
PB - American Society of Mechanical Engineers (ASME)
T2 - ASME-JSME-KSME 2019 8th Joint Fluids Engineering Conference, AJKFluids 2019
Y2 - 28 July 2019 through 1 August 2019
ER -