Effects of Degrees of Motion Freedom on Free-Fall of A Sphere in Fluid
Free-fall of a sphere in fluid is investigated at a Galileo number of 204 by direct numerical simulations (DNS). We mainly focus on the effects of different degrees-of-freedom (DOFs) of the sphere motion during free-fall. The characteristics of free-fall are compared with those of flow past a fixed...
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Published in | China ocean engineering Vol. 32; no. 5; pp. 605 - 613 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
Nanjing
Chinese Ocean Engineering Society
01.10.2018
Springer Nature B.V Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration (CISSE), Shanghai 200240, China State Key Laboratory of Ocean Engineering, Shanghai Jiao Tong University, Shanghai 200240, China |
Subjects | |
Online Access | Get full text |
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Summary: | Free-fall of a sphere in fluid is investigated at a Galileo number of 204 by direct numerical simulations (DNS). We mainly focus on the effects of different degrees-of-freedom (DOFs) of the sphere motion during free-fall. The characteristics of free-fall are compared with those of flow past a fixed sphere. Additional numerical tests are conducted with constraints placed on the translational or rotational DOFs of the sphere motion to analyze different DOFs of sphere motion. The transverse motion contributes significantly to the characteristics of free-fall; it results in the retardation of the vortex shedding, leading to the decrease of the Strouhal number. In addition, the transversal sphere motion exhibits the tendency to promote the sphere rotation. On the contrary, the effects of the sphere rotation and vertical oscillations during free-fall are negligible. |
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ISSN: | 0890-5487 2191-8945 |
DOI: | 10.1007/s13344-018-0062-5 |