DOI: 10.1016/j.atmosres.2017.09.008
Scopus记录号: 2-s2.0-85031919975
论文题名: Numerical Study of Motion of Falling Conical Graupel
作者: Chueh C.-C. ; Wang P.K. ; Hashino T.
刊名: Atmospheric Research
ISSN: 1698095
出版年: 2018
卷: 199 起始页码: 82
结束页码: 92
语种: 英语
英文关键词: CFD
; Conical graupel particles
; Fall attitudes
; Low Reynolds numbers
Scopus关键词: Computational fluid dynamics
; Degrees of freedom (mechanics)
; Drag
; Mechanics
; Reynolds number
; Damped oscillations
; Fall attitudes
; Horizontal movements
; Horizontal translation
; Hydrodynamic forces
; Low Reynolds number
; Position and orientations
; Six degrees of freedom
; Navier Stokes equations
; computational fluid dynamics
; drag coefficient
; hydrodynamic force
; Navier-Stokes equations
; numerical model
; oscillation
; Reynolds number
; snow
英文摘要: In the present study, the attitudes of freely-falling conical graupel with a realistic range of densities are investigated numerically by solving the transient Navier-Stokes equations and the body dynamics equations representing the 6-degrees-of-freedom motion. This framework allows us to determine the position and orientation of the graupel in response to the hydrodynamic force of the flow fields. The results show more significant horizontal movements than those cases with a fixed bulk density of ice assumed in our previous study. This is because the real graupel particles possess the density less than the bulk density of ice, which, in turn, leads to a relatively small mass and a relatively small set of moments of inertia. We demonstrate that, with the six degrees of freedom considered together, when Reynolds number is small, a typical damped oscillation occurs, whereas when Reynolds number is high, amplifying oscillation may occur which leads to more complicated and unpredictable flying attitudes such as tumbling. The drag coefficients obtained in the present study agree with the previous studies and can be approximated by that of spheres of the same Reynolds numbers. We also show that conical graupel can perform significant horizontal translations which can be on the order of 1 km in 1 h. © 2017 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/109021
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
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作者单位: Research Center for Environmental Changes, Academia Sinica, Taipei, Taiwan; Department of Atmospheric and Oceanic Sciences, University of Wisconsin-MadisonWI 53706, United States; Research Institute for Applied Mechanics, Kyushu University, Japan
Recommended Citation:
Chueh C.-C.,Wang P.K.,Hashino T.. Numerical Study of Motion of Falling Conical Graupel[J]. Atmospheric Research,2018-01-01,199