구 주위의 비정상 면대칭 및 비대칭 유동의 특성CHARACTERISTICS OF UNSTEADY PLANAR-SYMMETRIC AND ASYMMETRIC FLOWS OVER A SPHERE
- Other Titles
- CHARACTERISTICS OF UNSTEADY PLANAR-SYMMETRIC AND ASYMMETRIC FLOWS OVER A SPHERE
- Authors
- 김동주
- Issue Date
- 2008
- Publisher
- 한국전산유체공학회
- Keywords
- 구(Sphere); 보텍스 쉐딩(Vortex Shedding); 면대칭 유동(Planar-Symmetric flow); 비대칭 유동(Asymmetric Flow)
- Citation
- 한국전산유체공학회지, v.13, no.4, pp 39 - 44
- Pages
- 6
- Journal Title
- 한국전산유체공학회지
- Volume
- 13
- Number
- 4
- Start Page
- 39
- End Page
- 44
- URI
- https://scholarworks.bwise.kr/kumoh/handle/2020.sw.kumoh/22942
- ISSN
- 1598-6071
- Abstract
- Numerical simulations of laminar flow over a sphere are conducted to investigate the effect of the Reynolds number on the characteristics of vortex shedding. The Reynolds numbers considered are between 300 and 475, covering unsteady planar-symmetric and asymmetric flows. Results show that the unsteady planar-symmetric flow can be categorized into two different regimes: single-frequency regime and multiple-frequency regime. The former has a single frequency component due to periodic shedding of the vortices with the same strength in every shedding cycle, while the latter has multiple frequency components due to cycle-to-cycle variation in the strength of shed vortices with the shedding angle fixed. The multiple-frequency planar-symmetric flow, which is newly found in the present study, occurs at Re=330~360 between the single-frequency planar-symmetric flow and the asymmetric flow. On the other hand, the asymmetric flow occurs at Re365, where the vortices shed from the sphere show variation both in strength and shedding angle unlike the planar-symmetric flow. Also, it is shown that the breaking of planar symmetry is closely related to the imbalance of vortical strength between a pair of streamwise vortices.
- Files in This Item
- There are no files associated with this item.
- Appears in
Collections - Department of Mechanical Engineering > 1. Journal Articles
Items in ScholarWorks are protected by copyright, with all rights reserved, unless otherwise indicated.