...Paolo Silvestri; Federico Reggio; Carlo Alberto Niccolini Marmont Du Haut Champ; Mario Luigi Ferrari; Aristide Fausto Massardo Dynamic compressors operating region is mainly constrained by fluid-dynamic instabilities occurring at low mass flowrate conditions, such as surge and rotating stall...

... layouts as fuel cell systems. Instability phenomena limit the operating range of the whole compressor system, especially during fast transients. The target is therefore to extend the minimum flow limit in order to improve the operability of each unit while avoiding compressor surge operation...

... with experimental results. As an interesting result presented in this work [ 66 ] it can be mentioned that the shape of the inlet duct has a non-negligible effect on the radial velocity profile at diffuser inlet under mild surge conditions. Similarly, Chen et al. [ 67 ] validate the DES approach based on compressor...

... flow phenomena. Compressors are known to be affected by unstable flow conditions appearing at low mass flowrate conditions. The best known and most dangerous phenomenon is surge, which is a global instability affecting the entire impeller and regions upstream and downstream from it. A list...

... prior to deep surge and introduces a new approach to identify these disturbances using nonlinear feature extraction algorithms including phase-reconstruction of time-series signals and evaluation of a parameter called approximate entropy. To the best of our knowledge, this is the first time approximate...

... to rotating stall and surge operations. This analysis was carried out to extend the knowledge about these risk conditions: the systems equipped with large volume size connected to the machine present critical issues related to surge and stall prevention, especially during transient operations toward low mass...

... Measurement techniques Compressor stall Surge Centrifugal pumps Operability First, we compare the simplified coupling model (Fig. 4 ) with the numerical calculation of torsional stiffness using the same geometry (referenced by ANSI/AGMA 9004 standard). The full 3D FEM based on the axisymmetric...

... 21, 2014; published online March 21, 2014. Editor: David Wisler. 14 02 2014 21 02 2014 A hybrid control system has been proposed for compressor surge, which combines the active method with the passive method. A bleed valve was selected as the actuator in the proposed system...