흐름 중 스포일러를 장착한 해저배관의 자가 매설에 관한 실험적 연구

Abstract

Abstract

This paper deals with the mechanism of spoiler which induces scouring around pipeline. The design methodology taken to apply spoiler for accelerate pipeline being self-burial into the sand-bed by approaching experimental analysis. The experimental study is conducted to investigate self-burial ability of submarine pipeline on two different sand diameter consisting two sand-beds, 0.012 cm and 0.028 cm. Different heights of spoiler attached on top of pipeline by each case. Flume test is conducted with diameter 5 cm of PVC(Polyvinyl Chloride) pipe model applied the spoiler height 0.0 cm, 1.7 cm and 2.5 cm in steady current velocity about 0.2 m/s, 0.4 m/s, and 0.55 m/s. Models and flow velocity are reduced by scale factor as 15, according to geometric and kinematic similarity. Performed 54 cases of experiment to compare differences of scour depth underneath a pipe and extent of self-burial in time history. Measuring scour depth of all cases are suspended until maximum scour depth approaches within 20 to 40 minutes. As result of experimental study, the deepest scour depth appeared by 2.5 cm of spoiler height and the most effective self-burial ability is disclosed at 1.7 cm of spoiler height. Figured out the relationship between the relative scour depth and spoiler height through applying different conditions of flow velocity and sand diameter. Conducted analysis of scour depth by using Reynolds number. Compared of both experimental and calculated values of scour depth according to Kjeldsen et al. (1974) and Bijker & Leeuwenstein (1984).