scholarly journals Visualization of Inlet Flow Fields with Reverse Flow of a Centrifugal Compressor

2009 ◽  
Vol 29-1 (2) ◽  
pp. 1147-1147
Author(s):  
Shinichiro ARAMAKI ◽  
Shusuke SAKAMOTO ◽  
Yasuhiro FUNAKOSHI ◽  
Hiroshi HAYAMI
Keyword(s):  
Centrifugal Compressor ◽  
Reverse Flow ◽  
Flow Fields ◽  
Inlet Flow

Evolution of Reverse Flow in a Transonic Centrifugal Compressor at Near-Surge

2017 ◽  
Author(s):  
Kazutoyo Yamada ◽  
Masato Furukawa ◽  
Hiromitsu Arai ◽  
Dai Kanzaki
Keyword(s):  
Centrifugal Compressor ◽  
Reverse Flow ◽  
High Reliability ◽  
Pressure Rise ◽  
Flow Region ◽  
Flow Fields ◽  
Rotating Stall ◽  
Centrifugal Compressors ◽  
Transonic Centrifugal Compressor ◽  
Flow Phenomena

In process centrifugal compressors used in various types of plants, the compressor is the heart of a plant, and it requires high reliability. Therefore, prediction of the surge is important for centrifugal compressors. There have been numerous researches on the surge: study on improvement of surge margin, and study on the rotating stall, which is recognized as a precursor to surge, in impeller or diffuser of the compressor. However, the researches have not focused on the surge inception flow phenomena, namely detailed flow mechanism leading to the surge, although understanding of such flow phenomena is important for prediction of the surge. The paper describes in detail unsteady flow fields in a transonic centrifugal compressor at near-surge conditions. The flow fields have been investigated by detached eddy simulations (DES) using 400 million grid points. The simulation results show that the huge reverse flow region occupies the flow field near the shroud in the impeller at off-design condition, triggered by the blade stall at the tip of impeller full-blade, and it drastically develops at near-surge. It is also found that the rotating disturbance with reversed flow appears in the diffuser near the endwall at around peak pressure-rise point, and it eventually evolves into the rotating stall cell with a large reverse flow, blocking the flow inside the diffuser at near-surge.

Unsteady Computational Fluid Dynamics Investigation on Inlet Distortion in a Centrifugal Compressor

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
Armin Zemp ◽  
Albert Kammerer ◽  
Reza S. Abhari
Keyword(s):  
Centrifugal Compressor ◽  
Temporal Evolution ◽  
Flow Distribution ◽  
Forced Response ◽  
Inlet Section ◽  
Flow Distortion ◽  
Inlet Flow ◽  
Inlet Distortion ◽  
Forcing Function ◽  
Unsteady Fluid

Blade failure in turbomachinery is frequently caused by an excessive resonant response. Forced response of the blades originates from unsteady fluid structure interactions as conditioned in the inlet section by duct bends, struts, or inlet guide vanes. This paper presents the computational part of a research effort that focuses on the blade forced response in a centrifugal compressor. Unsteady fluid flow simulations are used to quantify the forcing function acting on the compressor blades due to inlet flow distortion. The measured inlet flow distribution is applied as inlet boundary conditions in the computation. The unsteady investigation provided the temporal evolution of the distorted flow through the compressor. The time-resolved blade pressure distribution showed the temporal evolution of the dynamic load on the blade surface caused by the inlet distortion. The results suggest that the forcing function is most sensitive in the leading edge region due to inlet angle variations. Toward the impeller stability line the increase in incidence caused separation on the suction side of the main blade and therefore considerably altered the amplitude and the phase angle of the unsteadiness. The investigation of the effect of idealizing the inlet flow distribution on the forcing function showed an increase in the peak amplitude of approximately 30% compared with the actual inlet flow distribution.

Investigation of Off-Design Performance of Vaned Diffusers in Centrifugal Compressors: Part II — A Low-Solidity Cascade Diffuser

2002 ◽  
Author(s):  
Jong-Sik Oh
Keyword(s):  
Secondary Flow ◽  
Flow Rate ◽  
Centrifugal Compressor ◽  
Three Dimensional ◽  
Flow Fields ◽  
Performance Parameters ◽  
Design Performance ◽  
And Performance ◽  
Compressor Map ◽  
Low Solidity Cascade Diffuser

As the second part of the author’s study, off-design behavior of the design and performance parameters in the low-solidity cascade diffuser in a centrifugal compressor is investigated. The experimental flange-to-flange compressor map serves the validity of application of the present CFD work to the detailed investigation of the low-solidity cascade diffuser. Some meanline design and performance parameters as well as three-dimensional internal secondary flow fields are studied when the flow rate is changed from deep choke to stall.

Design and Off-Design Flow Fields of a Transonic Centrifugal Compressor Impeller

2009 ◽  
Author(s):  
Seiichi Ibaraki ◽  
Kunio Sumida ◽  
Toru Suita
Keyword(s):  
Shock Wave ◽  
Flow Field ◽  
Flow Structure ◽  
Centrifugal Compressor ◽  
Flow Fields ◽  
Design Flow ◽  
Centrifugal Impeller ◽  
Tip Leakage ◽  
Operating Range ◽  
Transonic Centrifugal Compressor

For reasons of their small dimensions, relatively higher efficiency and wider operating range transonic centrifugal compressors are usually applied to turbochargers and turboshaft engines. The flow field of a transonic centrifugal impeller is completely three dimensional and accompanied by shock waves, tip leakage vortices, secondary flows and interactions of them. Especially the operating range of a transonic centrifugal compressor decreases rapidly with increased pressure ratio. The expansion of the compressor operating range is one of the important issues. Also the higher off-design performance is strongly required for the applications like as turbochargers which have to operate from near surge limit to choke limit. The authors carried out the detailed flow measurement of a transonic centrifugal impeller with an inlet Mach number of 1.3 at design and off-design conditions by using Laser Doppler Velocimeter (LDV) and high frequency pressure transducers. The flow fields of design and off-design conditions were compared and discussed in this paper. As a result authors found out the difference and the similarity of the flow structure between design and off-design conditions. The location of the shock wave differs with the flow rate and influences the flow field of the inducer. The interaction of the shock wave and tip leakage vortex shows the same manner. Also detailed Navier-Stokes computations were conducted to elucidate the complicated vortical flow structure with the experimental results.

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