Numerical Analysis on Effects of Free-Stream Turbulence Intensity on the Three-dimensional Turbulent Flow Characteristics in a Turbine Cascade

자유유동 난류강도가 터빈 캐스케이드내 3차원 난류유동 특성에 미치는 영향에 관한 전산해석

The objective of this study is to determine the influence of free-stream turbulent intensity on the three-dimensional turbulent flow in a linear turbine cascade. The range of free-stream turbulence intensity considered is 0.7~10%. This study was performed numerically. The results show that the mass averaged loss coefficient increased according to the increase of free-stream turbulence intensity due to increased value of the mass averaged total pressure loss coefficient which was higher than the decreased value of the mass averaged secondary flow loss coefficient. The loss coefficient distribution was changed suddenly at a free-stream turbulence intensity of 10% while the loss coefficient distribution was rarely changed at a lower free-stream turbulence intensity of 5%.