Rotating stalls are generally the first instability met in turbomachinery, before surges. This 3D phenomenon is characterized by one or more stalled flow cells which rotate at a fraction of the impeller speed. The goal of the present work is to shed some light on the entropy generation in a centrifugal fan under rotating stall conditions. A numerical simulation of entropy generation is carried ...

â â â  parsian alluvial fan system is a part of asyab-kharabeh fluvial system that response it to quaternary climate changes is the main goal of this study. for this aim, climatic proxies and traces in alluvial fan structure were investigated base d o n four categories: aggradation and degradation phases, debris flows, size changes in deposited materials and formation of alluvial fan tufas. pri...

Back-to-back testing has been done using NASA fan rotor 67 in the Glenn Research Center W8 Axial Compressor Test Facility. The rotor was baseline tested with a normal industrial RMS surface finish of 0.5-0.6 μm (20-24 microinches) at 60, 80 and 100% of design speed. At design speed the tip relative Mach number was 1.38. The blades were then removed from the facility and ultrapolished to a surfa...