Experiment on effects of slotted tailboard on flow field of transonic turbine linear cascade

Numerical and experimental investigations were performed to study the effect of the slotted tailboard on the periodicity of transonic gas turbine cascade. Computational fluid dynamics was employed to study the effect of tailboards for pressure distributions of the blades and cascade passage exits with different void ratios (10%, 15%, 30%, 50%) and pitch angles (70°, 71°, 72°), meanwhile experiment was performed to verify that the tailboard improved the periodicity of cascade passage exit flow field. Results showed that, without tailboard, pressure distributions of the blades deviated from the periodic result apparently and the periodicity error of the cascade passage exits was quite large. Pressure distributions were affected by tailboards with different void ratios and pitch angles, besides, the periodicity of the flow field can be improved with a tailboard of appropriate parameters. Pressure distributions of cascade passage exits were much closer to each other and the periodic result with void ratio of 50% and pitch angle of 70° tailboard when compared with no tailboard condition, while the periodicity errors of numerical and experimental results were reduced by 47.6% and 28.1%, respectively.