...Julien Marty; Lionel Castillon; Pierric Joseph The operating range of a compressor is limited by surge or rotating stall line, among others. Numerical simulations must accurately predict these phenomena. This study is based on the experimental compressor CME2, which is a low-subsonic axial...

..., the impeller rotating stall happens at the first critical point where the diffuser instability is also enhanced. This is caused by the increase of the flow non-uniformity at the impeller exit as well as increased diffuser inflow angle due to the impeller compressibility effect. Therefore, both the impeller...

... passages is used to conduct unsteady simulations that trace the onset of instability in the compressor. Backward-traveling rotating stall waves appear at the inlet of the radial diffuser when the compressor is throttled. Six stall cells propagate circumferentially at approximately 0.7% of the impeller...

...Zeyuan Yang; Yadong Wu; Hua Ouyang Rotating instability (RI) and rotating stall (RS) are two types of aerodynamic instability in axial compressors. The former features the side-by-side peaks below the blade passing frequency (BPF) in frequency spectra, and the latter represents one or more stall...

...Wei Li; Leilei Ji; Enda Li; Ling Zhou; Ramesh K. Agarwal The non-uniform disturbance in the circumferential direction is the essential cause of the occurrence of rotating stall in a turbomachinery. In order to study the effect of tip clearance leakage flow on rotating stall, the mixed-flow pump...

.... The simulation results show that an abnormal counter-propagating rotating stall in the vaned diffuser is detected near design condition. The rotating stall displays that four stall cells near the shroud side of the vaned diffuser propagate slowly at a rate of approximately 0.675% of the impeller rotating...

... working close to the nominal operating point. The spectral analysis (Sec. 6.3 ) will confirm that these are rotating stall cells linked to the frequencies that modulate the pressure time signals (see Fig. 6 ). Fig. 5 Instantaneous flow field of entropy at 83% span in the 2 π /8 configuration...

... and simulation mainly cover performance curves and time-domain pressure traces of Kulites during rotating stall. At two different fan speeds, the stall characteristics such as the number and rotating speed of the stall cells were well-matched to the experimental values. The mass flow rate and the loading...

... 2010 31 12 2010 21 07 2011 21 07 2011 compressible flow compressors finite difference methods flow instability Mach number rotational flow singular value decomposition vaneless diffuser rotating stall 3D compressible flow linear inviscid model The radial...

...Minsuk Choi; Mehdi Vahdati; Mehmet Imregun An implicit, time-accurate 3D compressible Reynolds-averaged Navier-Stokes (RANS) solver is used to simulate rotating stall inception and recovery, the so-called rotating stall hysteresis, in the case of a modern fan geometry. In the first instance...

... and Saume ( 26 ) studied the development of a rotating stall in a four-stage axial compressor. They observed an acoustic resonance in the form of a spinning acoustic mode with three periods around the circumference, noting that with a decreasing mean flow Mach number “the resonance frequency and phase...

... Stabilitätsverbesserung am Verdichter-Analyseverfahren. Abschlußbericht ,” Ruhr-Universität Bochum, Bochum, Germany. Levy , Y. , and Pismenny , J. , 2005 , “ High-Frequency Pressure Oscillations of Rotating Stall Type ,” Int. J. Turbo Jet Engines 0334-0082 , 22 , pp. 59 – 87 . Hellmich , B...

...Huu Duc Vo; Choon S. Tan; Edward M. Greitzer A computational study to define the phenomena that lead to the onset of short length-scale (spike) rotating stall disturbances has been carried out. Based on unsteady simulations, we hypothesize there are two conditions necessary for the formation...

...Ronald Mailach; Konrad Vogeler The stable operating range of axial compressors is limited by the onset of rotating stall and surge. These flow conditions endanger the reliability of operation and definitely have to be avoided in compressors of gas turbines. However, there is still a need to improve...

...Masahiro Ishida; Daisaku Sakaguchi; Hironobu Ueki By positioning the completely rough wall locally on the hub side diffuser wall alone in the vaneless diffuser, the flow rate of rotating stall inception was decreased by 42 percent at a small pressure drop of less than 1 percent. This is based...