• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.1005-1009
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• 2002

The objective of this research is to suggest the noise prediction method of the centrifugal compressor. It is focused on the Blade Passing Frequency (BPF) component which is regarded as the main part of the rotating impeller noise. Euler solver is used to simulate the flow-field of the centrifugal compressor and time-dependent pressure data are calculated to perform the near-field noise prediction by Ffowcs Williams-Hawkings (FW-H) formulation. Indirect Boundary Element Method (IBEM) is applied to consider the noise propagation effect. Pressure fluctuations of the inlet and the outlet in the centrifugal compressor impeller are presented and Sound Pressure Level (SPL) prediction results are compared with the experimental data.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.6
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• pp.103-110
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• 1997

A performance prediction method is presented for single(double) suction centrifugal pumps with a review of loss correlations given in the previous open literature. Most of the loss analyses mentioned in the present study are one dimensional and this paper investigates several modeling schemes and shows that a fairly good prediction can be achieved by a proper selection of the most important flow parameters resulting from a mean streamline analysis. Predictions of the trends of total head- capacity and pump efficiency-capacity curves agree well with the experimental data in almost the full range of operating conditions. The prediction method developed through this study can serve as a tool to ensure good matching between parts and it can assist the understanding of the operational characteristics of general purpose centrifugal pumps.

• The KSFM Journal of Fluid Machinery
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• v.2 no.1 s.2
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• pp.43-49
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• 1999

Flow field and near-field noise of a centrifugal fan has been studied with an efficient compressible method and STAR-CD. The flow field of the centrifugal fan is assumed to be two-dimensional. Most of the compressible studies have been done by inviscid solver because viscous simulation shows little difference. The near field noise is estimated in terms of sound pressure level in frequency domain transformed from the computed pressure fluctuations using FFT. The simulation has been done on various design elements such as impeller blade shapes, the number of blades and cut-off clearance. The comparison shows that the number of blades has a significant effect on near-field noise without losing aerodynamic performance.

• The KSFM Journal of Fluid Machinery
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• v.2 no.1 s.2
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• pp.50-55
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• 1999

The performance of a centrifugal fan depends on the dimensional parameters of impeller, such as the inlet and exit diameter, area ratio, relative flow angles to the blade, and the number of blades. These design parameters, however, are inter-related, so it is very difficult to identify the effect of each parameter on the fan performance. In this experimental study the effects of the design parameters on the performance of a small centrifugal impeller being used for vacuum cleaners are investigated. A total of 30 shrouded impellers with 120mm diameter were tested and the results were non-dimensionalized to compare their performance.

• The KSFM Journal of Fluid Machinery
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• v.2 no.1 s.2
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• pp.81-87
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• 1999

This study presents the measurement techniques on the periodic fluctuating flow such as the discharge flow of a centrifugal impeller in an unstable operating region. During rotating stall, the flow at the exit of a centrifugal compressor impeller fluctuates periodically with a lower frequency than that of the blade passing. To observe the blade-to-blade flow characteristics during the rotating stall, the phases of all the sampled data sets should be adjusted to those of the reference signals with two processes, in these processes, DPLEAT (Double Phase-Locked Ensemble Averaging Technique) can be used. From these measurements and data processing techniques, the characteristics illustrated a blade-to-blade flow with high frequency, but also a periodic rotating stall flow with a low frequency at the centrifugal impeller exit which was clearly observed.

• The KSFM Journal of Fluid Machinery
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• v.7 no.6 s.27
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• pp.38-44
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• 2004

In this study, the overall performance and the effect of the tip leakage flow of the centrifugal compressor with a refrigerant HFC-l34a were numerically studied using CFX-TASCflow. To study the effect of the tip leakage flow, the numerical study of the overall performance of HFC-l34a centrifugal compressor with a cascade diffuser was preceded and compared with the experimental result. Six different tip clearances were used to consider the influence of the tip clearance on the performance. The tip leakage flow was illustrated for qualitative discussion. The results obtained in this study can be applied to the determination of the cold clearance.

• 유체기계공업학회:학술대회논문집
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• 2004.12a
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• pp.405-410
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• 2004

2-dimensional impeller's distinctive feature is expected to have an influence on performance and flow characteristics of centrifugal compressor. And new design method is required for 2-dimensional impeller, because the unique geometry cannot be designed using conventional theories. The objective of this study is to advance new design technology for 2-dimensional impeller and to investigate the performance characteristics of designed 2-dimensional centrifugal compressor. The performance test for 2-dimensional impeller is conducted at 35000, 40000 and 45000rpm. Also numerical calculation is applied by using commercial CFD code, FLUENT, and the results are compared with experimental results.

• International Journal of Fluid Machinery and Systems
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• v.2 no.2
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• pp.121-126
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• 2009

The internal flow field in a centrifugal pump working at the several flow conditions has been measured by using the particle image velocimetry (PIV) technique with the laser induced fluorescence (LIF) particles and the refractive index matched (RIM) facilities. The impeller of the centrifugal pump has an outlet diameter in 100mm, and consists of six two-dimensional curvature backward swept blades of constant thickness. Measured results give reliable flow patterns in the pump. It is obvious that application of LIF particle and RIM are the key methods to obtain the right PIV measured results in pump internal flow.

• Proceedings of the SAREK Conference
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• 2005.11a
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• pp.558-563
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• 2005

In this paper, the effect of volute area distribution on the performance characteristic curve of a centrifugal pump were numerically studied using a commercial CFD code. To reduce the shutoff head, maintaining head and efficiency at a design flow rate, the flat head-capacity characteristic curves in which the head varies only slightly with capacity from shutoff to design capacity are frequency required. In order to control the shutoff head of a pump, several volute area distributions were proposed as a main parameter with the same impeller geometry. The calculation results show that the characteristic curve of a centrifugal pump can be controlled by modifying the area distribution with the same volute outlet area.

• The KSFM Journal of Fluid Machinery
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• v.16 no.6
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• pp.12-18
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• 2013

This paper presents the performance characteristics of a centrifugal blower using the design parameters of an impeller blade. Two design variables, the bending length from the blade trailing edge and bending angles of an impeller blade, are introduced to analyze the effects on the blower performance. Three-dimensional Navier-Stokes equations with shear stress transport turbulence model are introduced to analyze the performance and internal flow of the blower. Relatively good agreement between experimental measurements and numerical simulation at the design flow condition is obtained. Throughout present study, it is known that pressure increases as the bending length from the trailing edge and bending angle increase while efficiency decreases. But efficiency is decreased. Detailed flow field inside the centrifugal blower is also analyzed and compared.