Experimental study of endwall flow in a low-speed linear compressor cascade: effect of fillet radius

This paper describes the study of endwall flow modification due to the presence of fillet radius in axial compressor blades. A fillet is commonly used at the intersection between the blade and the endwall in axial turbomachinery blade-rows to improve the mechanical integrity by reducing the local stresses. Since the endwall region is affected by secondary flow, separation and vortices the presence of the fillet can potentially modify the flow mechanism that results, especially, in the endwall blade corner region. In this paper an experimental study into the effects of the fillet, namely, the modification of the secondary flows and the generation of the losses under a low Reynolds number condition is discussed. It has been shown that, for the range of cases tested, employment of a uniform blade fillet reduces the overturning secondary flow. The measurements reported in the paper show no detrimental effects due to the presence of the fillet but on the contrary finds that the endwall and mass averaged losses are marginally lower compared to when no fillets are employed.