Experimental Identification of a New Secondary Wave Pattern in Transonic Cascades with Porous Walls

Turbomachinery shock wave patterns occur as a natural result of operating at off-design points and are accountable for some of the loss in performance. In some cases, shock wave–boundary layer (SW-BLIs) interactions may even lead to map restrictions. The current paper refers to experimental findings...

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Bibliographic Details
Main Authors: Valeriu Drăgan, Oana Dumitrescu, Mihnea Gall, Emilia Georgiana Prisăcariu, Bogdan Gherman
Format: Article
Language:English
Published: MDPI AG 2024-11-01
Series:Aerospace
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Online Access:https://www.mdpi.com/2226-4310/11/11/946
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Summary:Turbomachinery shock wave patterns occur as a natural result of operating at off-design points and are accountable for some of the loss in performance. In some cases, shock wave–boundary layer (SW-BLIs) interactions may even lead to map restrictions. The current paper refers to experimental findings on a transonic linear cascade specifically designed to mitigate shock waves using porous walls on the blades. Schlieren visualization reveals two phenomena: Firstly, the shock waves were dissipated in all bladed passages, as predicted by the CFD studies. Secondly, a lower-pressure wave pattern was observed upstream of the blades. It is this phenomenon that the paper reports and attempts to describe. Attempts to replicate this pattern using Reynolds-averaged Navier–Stokes (RANS) calculations indicate that the numerical method may be too dissipative to accurately capture it. The experimental campaign demonstrated a 4% increase in flow rate, accompanied by minimal variations in pressure and temperature, highlighting the potential of this approach for enhancing turbomachinery performance.
ISSN:2226-4310