Investigation on Influence of Width and Position on Performance of Blended Blade and End Wall Cascade

Flow separation in corner zone is a key factor to limit the increase of compressor aerodynamic loading. Blended Blade and End Wall Design (BBEW) can efficiently organize the flow status in corner zone and reduce or eliminate the separations. In order to investigate the effects of maximum BBEW width and its position in chord on the performance of cascade, the baseline cascade and nine kinds of BBEW cascades were designed and the numerical simulation method verified by experimental data were carried out. The results show that for baseline cascade, the span wise height of the core position of the high loss zone is raised gradually with the increase of inlet flow incidence angle. The BBEW cascade performance is entirely different when the BBEW chord position is before or after the separation location. If the BBEW chord position is before the separation location, the effect of BBEW designs is more and more with the increase of inlet flow incidence angle. In +10°incidence angle, the best BBEW cascade can reduce the relative total pressure loss 16.2% compared with baseline cascade near the 14% span wise height. But if the chord wise position of the maximum BBEW width is located after the start point of flow separation, the BBEW design will increase the aerodynamic loss in the whole operational scope. There is optimum size for BBEW width. The size of the width should be smaller than the thickness of incoming boundary layer.