인문학
사회과학
자연과학
공학
의약학
농수해양학
예술체육학
복합학
지원사업
학술연구/단체지원/교육 등 연구자 활동을 지속하도록 DBpia가 지원하고 있어요.
커뮤니티
연구자들이 자신의 연구와 전문성을 널리 알리고, 새로운 협력의 기회를 만들 수 있는 네트워킹 공간이에요.
초록·키워드
The precessional vortex is usually developed in the draft tube during the operations at the turbine mode of a pump turbine with low flow-rate conditions as the off-design conditions. This vortex causes pressure fluctuation and instability for the operation of the pump turbine system, which results in system failure. The development of the precessional vortex is related to the strength of the swirl at the runner outlet with low flow-rate conditions. In this study, the definition of the swirl number was used to investigate the influence of the swirl intensity on the precessional vortex characteristic at the draft tube. Accordingly, three-dimensional steady- and unsteady-state Reynolds-averaged Navier-Stokes calculations were performed with a shear stress transport turbulence model and a two-phase flow analysis to observe the internal flow and unsteady pressure characteristics according to the precessional vortex. The precessional vortex was well captured in the draft tube cone within the specific range of swirl numbers. This vortex region showed the complicated internal flow and affected the higher unsteady pressure characteristics on the wall of the draft tube cone.
본문·목차
인공지능 문자 인식 모델을 통해 추출된 텍스트로, 일부 오타나 오류가 포함될 수 있으나 지속적으로 개선 중입니다.
오류를 발견하셨다면 해당 부분을 드래그한 후 ' 를 통해 신고해주세요.
오류를 발견하셨다면 해당 부분을 드래그한 후 ' 를 통해 신고해주세요.