Effect of Turbulence on the Development of Boundary Layer on the Turbine Cascade

• Main Authors: Shiang-Jye Wuu, 伍湘杰
• Other Authors: Jiun-Jih Miau
• Format: Others
• Language: zh-TW
• Published: 1995
• Online Access: http://ndltd.ncl.edu.tw/handle/13915353641564147806

碩士 === 國立成功大學 === 航空太空工程學系 === 83 === The purpose of this study is to investigate the effect of turbulence on the development of boundary layer on the turbine cascade. The freestream turbulence was controlled by three different kinds of grids, characterized by the turbulence intensities, ranging from 1.6% to 5.0%, and the integral length scales, ranging from 4.69mm to 9.55mm. Experiments were conducted in a low speed wind tunnel, including (1)the calibration of inlet flow uniformity, flow periodicity, and two-dimensionality, (2) surface oil flow visualization, (3)measurements of surface pressure distribution, (4)measurements of total pressure loss and deviation angle. Satisfactory flow quality was obtained by controlling the end-wall bleeding, tailboards arrangements, and sidewall suction rate. Measurements were made at an inlet velocity of about 10.7m/s, corresponding to the Reynolds number about 50,000 based on the blade chord. Flow separation on suction side was found in all cases studied. Higher the turbulence intensity further upstream is the transition location occurred, resulting into lower total pressure loss and exit deviation angle.