http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
김태호(T.H. Kim),瀨戶口俊明(T. Setoguchi),김희동(H.D.Kim) 대한기계학회 2002 대한기계학회 춘추학술대회 Vol.2002 No.5
A Wells turbine for the wave power conversion has generic hysteretic flow characteristics in a<br/> reciprocating flow. The hysteretic loop is opposite to the well-known dynamic stall of an airfoil. In the present<br/> study, the flow mechanism of the hysteretic behaviors was elucidated by the unsteady 3-dimensional Navier-<br/> Stokes computations. It was found that the hysteretic behaviors were caused by the streamwise vortical flows<br/> generated near the blade suction surface. The effects of the hub-to-tip ratio and tip clearance on the hysteretic<br/> flow characteristics of the Wells turbine were also discussed from a view of the practical design of the turbine<br/> blade.
파력발전용 웰즈터빈성능에 영향을 미치는 날개형상에 관한 연구
김태호(T.H. Kim),瀨戶口俊明(T. Setoguchi),김희동(H.D.Kim) 대한기계학회 2002 대한기계학회 춘추학술대회 Vol.2002 No.5
Optimization of the Wells turbine requires a clear understanding of the blade geometry effect on its<br/> performance. The complicated interrelations among the major parameters associated with the turbine<br/> geometry, like solidity, hub-to-tip ratio, aspect ratio, blade sweep ratio, and so on, make the overall<br/> performance of the turbine blade highly difficult and unpredictable. In the present study, the effect of the<br/> blade geometry with the hub-to-tip and aspect ratios on the turbine performance was investigated by a<br/> computational technique. In computation, the 3-dimensional, steady, incompressible, Reynolds-Averaged<br/> Navier-Stokes(RANS) equations were are solved by the finite volume method. It was found that the optimum<br/> blade geometry is obtained for the hub-to-tip ratio of 0.7, the aspect ratio of 0.5, the sweep ratio of 0.35, and<br/> the solidity of 0.67. Detailed flow patterns were obtained to discuss the turbine blade optimization.
역유동을 이용한 초음속 노즐에 작용하는 Pitching 효과에 대한 연구
임채민(C. M. Lim),김희동(H. D. Kim),瀨戶口俊明(T. Setoguchi) 대한기계학회 2005 대한기계학회 춘추학술대회 Vol.2005 No.5
In the modern aerospace industry the fluidic thrust-vector control, with simpler design, got considerable attention than the mechanical thrust-vector control because of its simpler design, low maintenance cost, high maneuverability and low aerodynamics drag. In the recent past many studies have been reported on fluidic thrust-vector control, nevertheless the application of the fluidic thrust-vector control is still in the infant stage due the lack of understanding of the pitching effect and the flow field associated with separation, strong unsteadiness, and the shock wave and boundary layer interaction. In this paper, both experimental and computational studies have been reported to examine the pitching effect on a supersonic nozzle using the counter-flow concept. The results obtained from both experimental and computational studies show that, for a given nozzle pressure ratio, the thrust vector angle has a maximum value at a certain suction flow rate, which is almost 5% of the mass flow rate of the primary jet.