조류유입 차단막을 설치한 댐의 용수취수 유입유동 특성 = Reservoir water intake flow characteristics from an intake tower surrounded an algal fence

다국어 초록 (Multilingual Abstract)

Shallow water withdrawal systems have been replaced with a selected withdrawal system to keep stable raw water quality in spite of occurrence of algae and muddy inflow. Before reconstruction of the water intake tower in Yongdam reservoir supplying water to Gosan water treatment facility, we have predicted flow patterns of inflowing water into the water intake tower for various withdrawal conditions.
Inflow pattern of water intake tower has been predicted by solving three-dimensional incompressible Navier-Stokes equations with a porous media modeling of an algal fence. In order to prevent the effects from boundary condition, very wide computational domain, where inlet and outlet boundaries are set up away from over 500 m and 220 m respectively, has been used with constant velocity outlet boundary condition corresponding to the flow rate.
Algal fence has been modeled to the 1.0 mm × 1.0 mm filter with 0.5 mm thickness, and the pressure drop has been predicted by CFD with various inlet velocity. From the results, both coefficients of permeability and inertial resistance factor have been estimated for the porous media modeling of the algal fence.
The simulations have been performed for the shallow, intermediate, bottom water withdrawal cases. It has been predicted that the water in the withdrawal layer is significantly inflowed from the front with fast velocity into the water intake tower irrespective of withdrawal depth, while the water away from the withdrawal layer is withdrawed a little from the side with slow velocity.
For a long algal fence of 10 m and 15 m, the inflowed water is diverted under the algal fence due to the pressure drop of the fence. Therefore shallow water is moved from the side of the gate to the front and flowed into the gate, and the ratio of the water from the side of the gate to one from the front is increased as the algal fence is long. The fence effects are more increased for the impermeable algal fence.
As the withdrawal layer is deep, the effects of the fence installed at the surface of the water are decreased, and are disappeared for the bottom water withdrawal case.
It is also predicted that the flow characteristics for large flow rate of 17.4 m3/s is similar to the that of 5 years averaged flow rate of 11.0 m3/s.
Consequently the selective water intake system have to be installed to prevent intake of algae and muddy flow.

목차 (Table of Contents)

• 제Ⅰ장 서 론 1
• 1. 연구 배경 1
• 2. 연구 목적 2
• 3. 용담댐 취수탑 시설 및 운영현황 3
• (1) 취수탑 시설현황 3
• (2) 취수탑 운영현황 4
• 제Ⅱ장 이론적 배경 5
• 1. 지배방정식 5
• (1) 비압축성 지배방정식 5
• (2) 난류모형 6
• 2. 수치해석 기법 9
• (1) 대류-확산문제를 위한 유한체적법 9
• (2) 정상 유동에서 압력-속도 결합 10
• 3. 전산유동해석 조건에 대한 검토 13
• (1) 해석조건 및 가정 13
• 4. 조류유입차단막 모델링 19
• (1) 모델링 개요 19
• (2) 적용방정식 20
• (3) 해석영역 및 경계조건 22
• (4) 유동해석 결과 23
• (5) 다공성매질로의 모델링 25
• 5. 취수탑 해석영역 및 격자 계산 27
• (1) 지배방정식 및 전산해석 기법 27
• (2) 해석영역 및 경계조건 28
• (3) 격자생성 30
• 제Ⅲ장 결과 및 고찰 32
• 1. 표면취수지 유입유동특성 32
• (1) 대칭면에서의 유동패턴 32
• (2) 3차원 유입유동패턴 35
• (3) 대칭면에서의 속도 분포 38
• 2. 선택취수 수심에 따른 유입유동특성 41
• (1) 취수 위치에 따른 구분 41
• (2) 수심에 따른 유입유동패턴 변화 42
• 3. 조류차단막 길이에 따른 유입유동 특성 59
• (1) 조류유입차단막 조건에 따른 구분 59
• (2) 표층취수시 조류유입차단막 길이에 대한 영향 60
• (3) 선택취수시 조류유입차단막 영향 65
• 4. 취수량에 따른 유입유동 특성 71
• (1) 취수유량 및 수위 선정 71
• (2) 취수량에 따른 유입유동 패턴 72
• 제Ⅳ장 결 론 80
• 참고 문헌 82