The Effect of Different Clapboards Structure in Turbine Blade Trailing Edge Complex Passages on Heat Transfer Characteristics

The experiment mainly aimed at to investigate the effect of different aperture in different clapboard structure in the turbine blade trailing edge complex passages on heat transfer and pressure drop characteristics. A thermochromic liquid crystal method was used to measure the detailed heat transfer coefficients on the end wall surfaces. Comparison of end wall heat transfer and pressure drop characteristics was made between two kinds of rectangular clapboards and two kinds of waved clapboard in the turbine blade trailing edge complex passages. It was found that the rectangular clapboard with aperture of 2-5 millimeter produces higher heat transfer with relatively less pressure drop than that of the rectangular clapboard with aperture of 1.8 millimeter; the heat transfer of the waved clapboard with aperture 1.5 millimeter in trough and aperture 2.1 millimeter on ridge was higher than that of the waved clapboard with aperture 2.1 millimeter in trough and aperture 3.0 millimeter on ridge. Comparing the four structures, the two waved clapboards performed the higher endwall-averaged heat transfer and in the meanwhile pay the lower pressure drop penalty than the two rectangular clapboards.