|제목(국문)||2차원 dune 유동의 대와류모사|
|제목(영문)||LARGE EDDY SIMULATION OF FLOW OVER 2 DIMENSIONAL DUNE|
(Kyoung Slk Chang
▷공저자 네트워크 보기
(G. Constantinescu ,University of Iowa, IIHR ) ▷공저자네트워크등록하기
The present large eddy simulation (LES) study focuses on the case of developing flow within wide channels containing at the bottom wall an array of 2D dunes (2a/h=0.25, I/h=3.75, I is the wavelength, 2a is the dune height, h is the mean channel depth) of closer shape to the ones observed in natural streams. For the case of an incoming steady flow, the instantaneous flow flelds are characterized by the formation of arrays of highly-organized hairpin vortices whose dimensions scale with the dune height, LES shows that for shallow channels (2a/h>0.25), the large-scale hairpins and the streaks penetrate regularly up to the free suiface, thus affecting mass transport and mixing over the whole water column. LES shows that the hairpin eddies play the primary role in the formation of the streaks of high and low momentum over the region containing dunes. The presence of resolved turbulence in the incoming flow reduces the streamwise distance needed for the streaks to develop over the rough bed region, but does not affect qualitatively the transition process toward the fully developed flow regime, nor the spacing of the streaks in the fully-developed flow region.
|keyword||대와류모사(Large Eddy Simulation), 2차원 모래언덕(2D Dune), 응집구조(Coherent Structure)|
|저널명||한국전산유체공학회 추계학술대회 ▷관련저널보기|