Numerical study of dividing open-channel flows at bifurcation channel using TELEMAC-2D

Dae Jin Jung; Chang-Lae Jang; Kwansue Jung

doi:10.3741/JKWRA.2016.49.7.635

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2016 Vol.49, Issue 7 Preview Page

Numerical study of dividing open-channel flows at bifurcation channel using TELEMAC-2D TELEMAC-2D모형을 이용한 개수로 분류흐름에 대한 수치모의 연구

31 July 2016. pp. 635-644

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Abstract

This study investigates variation of flow characteristics due to variation of branch channel width and discharge ratio at bifurcation channel using 2D numerical model. The calculated result considering secondary flow is more accurate and stable than without considering one. The diversion flow rate (Q₃/Q₁) is reduced by flow stagnation effect according to the interaction of the secondary flow and flow separation zone in branch channel. The less upstream inflow or the lower upstream velocity, the bigger variation of diversion flow rate by changing branch channel width. At uniform downstream boundary condition, the rate of change in Froude number of downstream of main channel(Fr₂)-diversion flow rate (Q₃/Q₁) relations is similar about -2.4843~-2.6675 when branch channel width ratio (b/B) is decreased. At uniform diversion flow rate (Q₃/Q₁) condition, the width of recirculation zone in branch channel is decreased when branch channel width ratio (b/B) is decreased. The less upstream inflow in the case of increasing branch channel width or the narrower branch channel width in the case of increasing upstream inflow, the bigger reduction ratio of recirculation zone width. At uniform inflow discharge (Q₁) condition, diversion flow rate, the width and length of recirculation zone in branch channel are decreased when branch channel width ratio (b/B) is decreased.

Keywords

Bifurcation

Variation of Branch Channel Width

Variation of Discharge Ratio

Secondary Flow

TELEMAC-2D

Recirculation Zone

본 연구에서는 2차원 수치모형을 이용하여 개수로 분류부에서 분류수로 폭과 유량비 변화에 따른 흐름특성을 파악하였다. 2차류 영향을 고려한 분류부 수치모의시 흐름분포를 실험결과에 더 정확하고 안정하게 모의가능하다. 분류수로내 통수능을 감소시키는 흐름분리구역과 2차류의 상호작용에 의한 흐름정체 효과는 분류유량비를 감소시킨다. 분류부 상류 유입유량과 유속이 감소할수록 수로폭 변화에 따른 분류유량비 변화가 더 크다. 동일 하류단 경계조건에서 분류수로 폭을 감소시킬 때, 본류 하류부 프루우드 수-분류유량비 관계식의 변화율은 –2.4843~-2.6675로 유사하게 나타난다. 동일 분류유량비 조건에서 분류수로 폭이 감소할수록 수축계수는 증가하고, 흐름분리구역의 폭은 감소한다. 분류수로 폭을 증가시킬 경우 분류부 상류 유입유량이 적을수록, 그리고 분류부 상류 유입량을 증가시킬 경우 분류수로 폭이 좁을수록 흐름분리구역 폭 감소율이 더 크다. 동일 상류 유입유량 조건에서 분류수로 폭이 감소할수록 분류유량비, 흐름분리구역의 길이와 폭은 감소한다.

키워드

분류부

분류 수로폭 변화

유량비 변화

2차류

TELEMAC-2D

흐름분리구역

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Information

Publisher :KOREA WATER RESOURECES ASSOCIATION
Publisher(Ko) :한국수자원학회
Journal Title :Journal of Korea Water Resources Association
Journal Title(Ko) :한국수자원학회 논문집
Volume : 49
No :7
Pages :635-644
Received Date : 2016-03-21
Revised Date : 2016-06-13
Accepted Date : 2016-06-25
DOI :https://doi.org/10.3741/JKWRA.2016.49.7.635

Journal of Korea Water Resources Association ISSN:2799-8746(Print) 2799-8754(Online) 한국수자원학회 논문집

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