Detection and Analysis of an Alternate Flow Pattern in a Radial Vaned Diffuser

International Journal of Turbomachinery, Propulsion and Power

Isabelle Trébinjac¹  Pierre Duquesne¹  Victor Moënne-Loccoz¹  Nicolas Poujol² 

[1] Ecole Centrale de Lyon, LMFA, UMR CNRS 5509, 36 Avenue Guy de Collongue, 69134 Écully, France;SAFRAN Helicopter Engines, Av. Joseph Szydlowski, 64510 Bordes, France;

关键词: centrifugal compressor;    vaned diffuser;    stall;    experiments;   

DOI  :  10.3390/ijtpp5010002

来源: DOAJ

【 摘 要 】

The flow in the vaned diffuser of an aeronautical centrifugal compressor designed by Safran Helicopter Engines is analyzed through steady and unsteady pressure measurements at different rotation speeds. The analysis leads to the identification of different operating zones thanks to a new variable, the alternate rate ?. It allows the characterization of a specific behavior of the vaned diffuser consisting of an alternate stall pattern in two adjacent channels of the diffuser. While it is close to zero at low speed, the alternate rate reaches a maximum value at a higher speed before collapsing with a further increase in the rotation speed. Depending on the value reached by the alternate rate, three distinct regimes of the flow within the diffuser can be distinguished. For low ? values, the regime is the most common one with an equivalent flow pattern in each channel of the diffuser. For moderate ? values, a mild difference of the flow fields which develop in two adjacent channels can be observed but it remains time independent. Finally, for high values of ?, the alternate pattern is amplified and becomes time dependent, pulsating together with the mild surge of the entire compressor.

【 授权许可】

Unknown