TY - JOUR
T1 - Rising and Sinking in Resonance
T2 - Mass Distribution Critically Affects Buoyancy-Driven Spheres via Rotational Dynamics
AU - Will, Jelle B.
AU - Krug, Dominik
N1 - Funding Information:
We thank Varghese Mathai, Chong Shen Ng, Chao Sun, and Detlef Lohse for insightful discussions as well as Jim Scheefhals for assisting in the experiments. This work was supported by the Netherlands Organisation for Scientific Research (NWO) under VIDI Grant No. 13477. This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No. 950111 BU-PACT).
Funding Information:
We thank Varghese Mathai, Chong Shen Ng, Chao Sun, and Detlef Lohse for insightful discussions as well as Jim Scheefhals for assisting in the experiments. This work was supported by the Netherlands Organisation for Scientific Research (NWO) under VIDI Grant No. 13477. This project has received funding from the European Research Council (ERC) under the European Union-s Horizon 2020 research and innovation programme (grant agreement No. 950111 BU-PACT).
Publisher Copyright:
© 2021 American Physical Society.
PY - 2021/4/30
Y1 - 2021/4/30
N2 - We present experimental results for spherical particles rising and settling in a still fluid. Imposing a well-controlled center of mass offset enables us to vary the rotational dynamics selectively by introducing an intrinsic rotational timescale to the problem. Results are highly sensitive even to small degrees of offset, rendering this a practically relevant parameter by itself. We further find that, for a certain ratio of the rotational to a vortex shedding timescale (capturing a Froude-type similarity), a resonance phenomenon sets in. Even though this is a rotational effect in origin, it also strongly affects translational oscillation frequency and amplitude, and most importantly, the drag coefficient. This observation equally applies to both heavy and light spheres, albeit with slightly different characteristics for which we offer an explanation. Our findings highlight the need to consider rotational parameters when trying to understand and classify path properties of rising and settling spheres.
AB - We present experimental results for spherical particles rising and settling in a still fluid. Imposing a well-controlled center of mass offset enables us to vary the rotational dynamics selectively by introducing an intrinsic rotational timescale to the problem. Results are highly sensitive even to small degrees of offset, rendering this a practically relevant parameter by itself. We further find that, for a certain ratio of the rotational to a vortex shedding timescale (capturing a Froude-type similarity), a resonance phenomenon sets in. Even though this is a rotational effect in origin, it also strongly affects translational oscillation frequency and amplitude, and most importantly, the drag coefficient. This observation equally applies to both heavy and light spheres, albeit with slightly different characteristics for which we offer an explanation. Our findings highlight the need to consider rotational parameters when trying to understand and classify path properties of rising and settling spheres.
UR - http://www.scopus.com/inward/record.url?scp=85105650413&partnerID=8YFLogxK
U2 - 10.1103/PhysRevLett.126.174502
DO - 10.1103/PhysRevLett.126.174502
M3 - Article
AN - SCOPUS:85105650413
SN - 0031-9007
VL - 126
JO - Physical review letters
JF - Physical review letters
IS - 17
M1 - 174502
ER -