【摘 要】
:
In the current state-of-the-art,high-loss flow in the endwall significantly influences com-pressor performance.Therefore,the control of endwall corner separation in compressor blade rows is important to consider.Based on the previous research of the Blend
【机 构】
:
School of Aerospace Engineering,Beijing Institute of Technology,Beijing 100081,China;Poly Technologi
论文部分内容阅读
In the current state-of-the-art,high-loss flow in the endwall significantly influences com-pressor performance.Therefore,the control of endwall corner separation in compressor blade rows is important to consider.Based on the previous research of the Blended Blade and EndWall(BBEW) technique,which can significantly reduce corner separation,in combination with a non-axisymmetric endwall,the full-BBEW technique is proposed in this study to further reduce the sep-aration in endwall region.The principle of the unchanged axial passage area is considered to derive the geometric method for this technique.Three models are further classified based on different geo-metric characteristics of this technique:the BBEW model,Inclining-Only EndWall (IOEW) model,and full-BBEW model.The most effective design of each model is then found by performing several optimizations at the design point and related numerical investigations over the entire operational conditions.Compared with the prototype,the total pressure loss coefficient decreases by 7% 9%in the optimized full-BBEW at the design point.Moreover,the aerodynamic blockage coefficient over the entire operational range decreases more than the other models,which shows its positive effect for diffusion.This approach has a larger decrease at negative incidence angles where the inter-section of the boundary layer plays an important role in corner separation.The analysis shows that the blended blade profile enlarges the dihedral angle and creates a span-wise pressure gradient to move low momentum fluid towards the mainstream.Furthermore,the inclining hub geometry accelerates the accumulated flow in the corner downstream by increasing the pressure gradient.Overall,though losses in the mainstream grow,especially for large incidences,the full-BBEW tech-nique effectively reduces the separation in corners.
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