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Original Article

Effectiveness Analysis of a Vertical Water-Injection Technique for Scour Mitigation Immediately Downstream of the Apron

물받이공 직하류 세굴 저감을 위한 연직 물 주입 기법의 효과 분석

Jeong Hu Lee1
,
Chang Geun Song2*
이 정후1
,
송 창근2*
1Postdoctoral Researcher, Department of Safety Engineering, Incheon National University, Incheon 22012, Korea
2Professor, Department of Safety Engineering, Incheon National University, Incheon 22012, Korea
1인천대학교 안전공학과 박사후연구원
2인천대학교 안전공학과 교수
*Corresponding Author
31 December 2025. pp. 240-251
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Abstract

The local scour downstream of a rigid apron, caused by submerged wall jets from sluice gate openings, is critically important as it poses a significant threat to structural stability. This study examines the impact of water injection at the apron’s end on flow structures and scour mitigation under a wall jet flow. A coupled numerical model for scour simulation was developed by integrating the Large Eddy Simulation (LES) model, the Discrete Element Method (DEM), and the Volume of Fluid (VOF) method within the open-source CFD software OpenFOAM. Validation of the numerical model shows a good agreement between the simulation results and observed data, confirming the model’s reliability. The numerical model was used to analyze the quantitative changes in flow structures and scour morphology by increasing the vertical water injection flow rate ratio (defined as the ratio of injection flow rate to the wall jet flow rate) from 0 to 0.25. The results indicated that as the injection flow rate ratio increased, the streamwise mean velocity and bed shear stress near the apron decreased, leading to significant reductions in both bedload transport rate and maximum scour depth. Specifically, when the injection flow rate ratio was 0.1, 0.2, and 0.25, the maximum scour depth was reduced by 40.82%, 63.27%, and 95.92%, respectively. These findings demonstrate that vertical water injection at the downstream end of the apron can serve as an effective countermeasure for local scour mitigation. Compared to conventional scour protection techniques, this method offers greater flexibility and adaptability in hydraulic structure design. Future research will investigate the scour reduction effects under various flow conditions and configurations of injection slot geometry.

Keywords
Discrete element method
Large eddy simulation
Local scour
Wall jet
Water injection

수문 개구부를 통해 방류되는 수중 벽제트는 보 하도 하류에서 국부 세굴을 유발하며, 이는 수공 구조물의 안정성을 위협하는 주요 요인 중 하나이다. 본 연구에서는 벽제트 흐름 하에서 하도 종단에서의 연직 물 주입이 유동 구조 및 세굴 저감에 미치는 영향을 수치적으로 분석하였다. 이를 위해, 3차원 계산유체역학 소프트웨어인 OpenFOAM을 기반으로, LES (Large Eddy Simulation) 난류 모형, DEM (Discrete Element Method) 기법, VOF (Volume of Fluid) 기법을 통합한 결합 세굴 수치모형을 구축하였다. 구축된 수치모형을 통해 얻은 유동 구조 및 세굴 형상 결과를 실험 자료와 비교한 결과, 양호한 일치도를 보여 모형의 신뢰성을 확보하였다. 수치모형을 이용하여 개구부 방류 체적 유량에 대한 물 주입 유량비를 0에서 0.25까지 단계적으로 증가시키며 유동 구조 및 세굴 형상의 정량적 변화를 분석하였다. 그 결과, 물 주입 유량비가 증가할수록 하도 인근 흐름 방향 평균 유속과 바닥 전단응력이 감소하였으며, 이에 따라 소류사 이송률과 세굴심 모두 유의미하게 저감되는 경향을 보였다. 결과적으로, 개구부 방류 체적 유량에 대한 물 주입 유량비가 0.1, 0.2, 0.25일 때, 최대 세굴심은 각각 40.82%, 63.27%, 95.92% 감소하는 것으로 나타났다. 본 연구의 주요 결론은 하도 종단에서의 물 주입이 하류 세굴 저감에 효과적인 수단이 될 수 있으며, 기존의 세굴 저감 대책들에 비해 수공 구조물 설계에 있어 보다 높은 유연성과 대응력을 제공할 수 있음을 보여준다는 점이다. 향후 연구에서는 다양한 유동 조건 및 주입 슬롯 구성 변화에 따른 세굴 저감 효과를 추가적으로 분석할 계획이다.

키워드
DEM
LES
국부 세굴
벽제트
물 주입
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Information
  • Publisher :Korean Society of Ecology and Infrastructure Engineering
  • Publisher(Ko) :응용생태공학회
  • Journal Title :Ecology and Resilient Infrastructure
  • Journal Title(Ko) :응용생태공학회 논문집
  • Volume : 12
  • No :4
  • Pages :240-251
  • Received Date : 2025-10-15
  • Revised Date : 2025-11-16
  • Accepted Date : 2025-11-27
  • DOI :https://doi.org/10.17820/eri.2025.12.4.240
Journal Informaiton Ecology and Resilient Infrastructure Ecology and Resilient Infrastructure
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