Experimental Investigation of Surge Phenomena in a Transonic Centrifugal Compressor

2019 ◽  
Author(s):  
Sasuga Ito ◽  
Masato Furukawa ◽  
Satoshi Gunjishima ◽  
Hiroki Usuki ◽  
Takafumi Ota ◽  
...  
Keyword(s):  
Unsteady Flow ◽  
Centrifugal Compressor ◽  
Static Pressure ◽  
High Response ◽  
Low Flow ◽  
Pipeline System ◽  
Flow Phenomenon ◽  
Pressure Transducers ◽  
Transonic Centrifugal Compressor ◽  
Response Pressure

Abstract Surge is an unsteady flow phenomenon occurring at low flow rates in the pipeline system including compressors. The surge is a phenomenon that must be avoided because of the danger in the operation: the pipeline equipment can be damaged or the operation cannot be continued. Experimental work is required not only to understand the unsteady behavior but to also validate the CFD used for more localized analysis and development of the understanding of the flow phenomena when operating near surge. Nevertheless, there are still many unclear points not only about the flow phenomenon at the inception of the surge which is important for the prediction of the surge but also about the surge behavior itself. Especially, as for the surge occurring in transonic centrifugal compressors, there are currently few experimental research cases due to the difficulty of the unsteady measurement. In this research, we measured the time variations in pressure and flow rate in a transonic centrifugal compressor for a vehicle turbocharger which consists of an impeller, vaneless diffuser and scroll. In the experiments, the measurement pipes were set upstream and downstream of the compressor and the velocity and the wall static pressure were measured with an I-type hot wire probe and high response pressure transducers, respectively. In addition, to investigate the process and the occurrence point of the back flow in surge, the wall static pressure was measured by means of high response pressure transducers which were mounted on the shroud upstream of the impeller and the diffuser hub at the two-circumferential positions, respectively. As the result of the experiments, the unsteady flow process during the mild and deep surges was measured and the inception of deep surge was clarified.

Experimental Investigation of Surge Phenomena in a Transonic Centrifugal Compressor With Inlet Distortion

2020 ◽  
Author(s):  
Sasuga Ito ◽  
Masato Furukawa ◽  
Satoshi Gunjishima ◽  
Takafumi Ota ◽  
Kazuhito Konishi ◽  
...  
Keyword(s):  
Flow Rate ◽  
Centrifugal Compressor ◽  
Flow Instability ◽  
Pressure Sensors ◽  
Low Flow ◽  
Inlet Distortion ◽  
Transonic Centrifugal Compressor ◽  
Response Pressure ◽  
Surge Phenomena ◽  
Low Flow Rate

Abstract Inlet distortion has influence on the aerodynamic performance of turbomachinery such as compressors, turbines and fans. On turbochargers, bent pipes are installed around the compressor due to the spatial limitations in the engine room of the vehicle. As the result, the compressor is operated with the distorted inflow. In the low flow rate operation, the distorted inflow also affects the flow instability like stall and surge. Especially, the operation range on the low flow rate side is defined based on the flow rate where surge occurs, so it is important to investigate the effect of the distorted inflow on surge. In this study, the effect of the inlet distortion to surge phenomena has been investigated by the experiments with a transonic centrifugal compressor. A bent pipe has been installed at the upstream of the compressor to generate a distorted flow. Experiments have been also conducted under the condition that a straight pipe was installed upstream of the compressor, and unsteady measurements with high response pressure sensors and an I-type hot wire probe have been carried out to each experiments. In addition, Fast Fourier transform (FFT) and Wavelet transform have been applied to the unsteady measurement results obtained from each experiment.

Numerical Investigation of the Unsteady Flow Inside a Centrifugal Compressor Stage With Pipe Diffuser

2013 ◽  
Vol 136 (3) ◽  
Author(s):  
Daniel R. Grates ◽  
Peter Jeschke ◽  
Reinhard Niehuis
Keyword(s):  
Experimental Data ◽  
Unsteady Flow ◽  
Centrifugal Compressor ◽  
Measurement Techniques ◽  
Navier Stokes ◽  
Compressor Stage ◽  
Centrifugal Compressor Stage ◽  
Transonic Centrifugal Compressor ◽  
Computational Fluid Dynamics Cfd ◽  
The Subject

The subject of this paper is the investigation of unsteady flow inside a transonic centrifugal compressor stage with a pipe-diffuser by utilizing unsteady 3D Reynolds-averaged Navier–Stokes simulations (unsteady 3D URANS). The computational fluid dynamics (CFD) results obtained are compared with detailed experimental data gathered using various steady and unsteady measurement techniques. The basic phenomena and mechanisms of the complex and highly unsteady flow inside the compressor with a pipe-diffuser are presented and analyzed in detail.

Unsteady Flow Phenomena in a Transonic Centrifugal Compressor at near-surge conditions

2016 ◽  
Vol 2016 (0) ◽  
pp. J0520202
Author(s):  
Atsuki OKAMOTO ◽  
Hiromitsu ARAI ◽  
Masato FURUKAWA ◽  
Satoshi GUNJISHIMA ◽  
Kazutoyo YAMADA
Keyword(s):  
Unsteady Flow ◽  
Centrifugal Compressor ◽  
Transonic Centrifugal Compressor ◽  
Flow Phenomena

An Experimental Investigation of Stator Induced Unsteadiness on Centrifugal Impeller Outflow

1996 ◽  
Vol 118 (1) ◽  
pp. 41-51 ◽  
Author(s):  
M. Ubaldi ◽  
P. Zunino ◽  
G. Barigozzi ◽  
A. Cattanei
Keyword(s):  
Static Pressure ◽  
Fast Response ◽  
Centrifugal Impeller ◽  
Flow Measurements ◽  
Vaned Diffuser ◽  
Pressure Transducers ◽  
Front End ◽  
Impeller Outlet ◽  
Instantaneous Flow Field ◽  
Response Pressure

Detailed flow measurements were taken in a centrifugal turbomachine model to investigate the aerodynamic influence of the vaned diffuser on the impeller flow. The model consists of an unshrouded centrifugal impeller with backswept blades and a rotatable vaned diffuser, which enables a continuous variation of the vaned diffuser location with respect to the measuring points. Phase-locked ensemble-averaged velocity components have been measured with hot-wire probes at the impeller outlet for 30 different relative positions of the probe with respect to the diffuser vanes. The data also include the distribution of the ensemble-averaged static pressure at the impeller front end, taken by means of miniature fast response pressure transducers flush-mounted at the impeller stationary casing. By circumferentially averaging the results obtained for the different circumferential probe locations, the periodically perturbed impeller flow has been split into a relative steady flow and a stator-generated unsteadiness. The results for the different probe positions have also been correlated in time to obtain instantaneous flow field images in the relative frame, which provide information on the various aspects of the diffuser vane upstream influence on the relative flow leaving the impeller.

An Experimental Investigation of Stator Induced Unsteadiness on Centrifugal Impeller Outflow

1994 ◽  
Author(s):  
Marina Ubaldi ◽  
Pietro Zunino ◽  
Glovanna Barigozzi ◽  
Andrea Cattanel
Keyword(s):  
Static Pressure ◽  
Fast Response ◽  
Centrifugal Impeller ◽  
Flow Measurements ◽  
Vaned Diffuser ◽  
Pressure Transducers ◽  
Front End ◽  
Impeller Outlet ◽  
Instantaneous Flow Field ◽  
Response Pressure

Detailed flow measurements were taken in a centrifugal turbomachine model to investigate the aerodynamic influence of the vaned diffuser on the impeller flow. The model consists of an unshrouded centrifugal impeller with backswept blades and a rotatable vaned diffuser which enables a continuous variation of the vaned diffuser location with respect to the measuring points. Phase locked ensemble averaged velocity components have been measured with hot wire probes at the impeller outlet for 30 different relative positions of the probe with respect to the diffuser vanes. The data also include the distribution of the ensemble averaged static pressure at the impeller front end, taken by means of miniature fast response pressure transducers flush mounted at the impeller stationary casing. By circumferentially averaging the results obtained for the different circumferential probe locations, the periodically perturbed impeller flow has been split into a relative steady flow and a stator generated unsteadiness. The results for the different probe positions have also been correlated in time to obtain instantaneous flow field images in the relative frame, which provide information on the various aspects of the diffuser vane upstream influence on the relative flow leaving the impeller.

J055032 Unsteady Flow Structures in the Vaneless Diffuser of a Transonic Centrifugal Compressor

2013 ◽  
Vol 2013 (0) ◽  
pp. _J055032-1-_J055032-5
Author(s):  
Takashi NISHIZAWA ◽  
Ryuichi HASHIMOTO ◽  
Kazutoyo YAMADA ◽  
Masato FURUKAWA ◽  
Seiichi IBARAKI ◽  
...  
Keyword(s):  
Unsteady Flow ◽  
Centrifugal Compressor ◽  
Flow Structures ◽  
Vaneless Diffuser ◽  
Transonic Centrifugal Compressor

scholarly journals Comparative Study of Unsteady Flows in a Transonic Centrifugal Compressor With Vaneless and Vaned Diffusers

2001 ◽  
Author(s):  
Michael M. Cui
Keyword(s):  
Flow Field ◽  
Unsteady Flow ◽  
Centrifugal Compressor ◽  
Three Dimensional ◽  
Power Laws ◽  
Working Fluid ◽  
Local Flow ◽  
Transonic Centrifugal Compressor ◽  
Compressor Performance ◽  
Overall Performance

To reduce vibration and noise level, the impeller and diffuser blade numbers inside an industrial compressor are typically chosen without common divisors. The shapes of volutes or collectors in these compressors are also not axis-symmetric. When impeller blades pass these asymmetric structures, the flow field in the compressor is time-dependent and three-dimensional. To obtain a fundamental physical understanding of these three-dimensional unsteady flow fields and assess their impact on the compressor performance, the flow field inside the compressors needs to be studied as a whole to include asymmetric and unsteady interaction between the compressor components. In current study, a unified three-dimensional numerical model was built for a transonic centrifugal compressor including impeller, diffusers, and volute. HFC 134a was used as the working fluid. The thermodynamic and transport properties of the refrigerant gas were modeled by the Martin-Hou equation of state and power laws, respectively. The three-dimensional unsteady flow field was simulated with a Navier-Stokes solver using the k-ε turbulent model. The overall performance parameters are obtained by integrating the field quantities. Both unsteady flow field and overall performance are analyzed comparatively for each component. The compressor was tested in a water chiller system instrumented to obtain both overall performance data and local flow field quantities. The experimental and numerical results agree well. The correlation between the overall compressor performance and local flow field quantities is defined. The methodology developed and data obtained in these studies can be applied to centrifugal compressor design and optimization.

Effects of Inlet Pressure Distortion on the Performance and Flow Field of a Centrifugal Compressor at Off-Design Conditions

2012 ◽  
Author(s):  
N. Sitaram ◽  
M. Govardhan ◽  
K. V. Murali
Keyword(s):  
Flow Field ◽  
Centrifugal Compressor ◽  
Total Pressure ◽  
Static Pressure ◽  
Design Flow ◽  
Flow Coefficient ◽  
Low Flow ◽  
Performance Measurements ◽  
Perforated Sheet ◽  
Sector Angle

The present paper presents experimental results on the effects of inlet total pressure distortion on the performance and flow field of a centrifugal compressor. The total pressure at inlet is artificially distorted by means of a perforated sheet, which is supported by a support mesh. A total of eleven configurations, including clean inlet configuration, are tested. Performance measurements and impeller inlet and exit flow studies at three flow coefficients, one near design flow coefficient, one below design flow coefficient and one above design flow coefficient, are carried out. The present paper presents and discusses results at off-design flow coefficients and the effects of stage loading on the distortion effects are presented. A new parameter, Distortion Index (DI) is introduced. As DI increases, the mass averaged total pressure at exit stations decreases. Distortion sector angle of 60° having the lowest total pressure is found to be the critical sector for circumferential distortion configurations. As the Distortion Correlation parameter, DC(60) increases, the mass averaged total pressure for circumferential distortion configuration decreases, except in the case of low flow coefficient where DC(60) is nearly constant. DC(60) also increases with sector angle. The static pressure normalized with static pressure for clean inlet decreases as the distortion sector angle is increased. Distortion attenuates the static pressure as the flow passes through the vaneless diffuser. The attenuation increases with the distortion sector angle.

An Experimental Investigation Into Unsteady Blade Forces and Blade Losses in Axial Compressor Blade Cascade

1986 ◽  
Vol 108 (1) ◽  
pp. 47-52 ◽  
Author(s):  
F. Sugeng ◽  
K. Fiedler
Keyword(s):  
High Speed ◽  
Axial Compressor ◽  
High Response ◽  
Digital Data ◽  
Wind Tunnels ◽  
Dynamic Changes ◽  
Pressure Transducers ◽  
Blade Row ◽  
Response Pressure ◽  
Hot Film

The unsteady flow problem in the axial compressor has been simulated in wind-tunnels by means of high-speed rotating cylinders upstream of the blade row. To obtain the dynamic changes in the flow properties 20 high-response pressure transducers and 20 high-response hot-film, which are embedded at the surface of the selected blade, have been used in connection with a periodic sampling and averaging technique in digital data acquisition and reduction. The fluctuating forces and the fluctuating drags acting on the blade due to passing wakes shedding through the blade row are carried out.

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