• Transactions of the Korean Society of Mechanical Engineers B
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• v.23 no.9
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• pp.1129-1138
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• 1999

This paper presents a systematic two-zone modeling for reliable performance prediction of centrifugal compressors. In order to improve the predictive capability, a modified jet slip factor is developed and new corrections for the wake flow deviation and mass fraction are suggested based on the comprehensive experimental data of the three Eckardt impellers. The proposed two-zone modeling is tested against nine sets of measured data of centrifugal compressors. The results are also compared with those obtained by the mean streamline analysis. It was found that the predictions by the present two-zone modeling agree fairly well with experimental data for a variety of centrifugal compressors over the wide operating conditions.

• The KSFM Journal of Fluid Machinery
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• v.3 no.3 s.8
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• pp.12-18
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• 2000

In this study, experimental and numerical analyses are carried out to investigate the performance of centrifugal pump with various air admitting conditions. Experiments on the pump performance under air-water two-phase flow are accomplished using a centrifugal pump with semi-open type impeller having three, five and seven blades, respectively. Also, the numerical analysis of turbulent air-water two-phase flow using the finite volume method has been carried out to obtain the pressure, velocities and void fraction on the basis of a so-called bubbly flow model with the constant size and shape of cavity. The results obtained through this study show the reasonable agreements within the range of bubbly flow regime. There are promising developments concerning application of the present study for the flow in a centrifugal pump with two-phase flow conditions and efforts must be followed to improve the turbulence model and two-phase flow model for turbomachinery.

• 유체기계공업학회:학술대회논문집
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• 2001.11a
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• pp.48-53
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• 2001

A centrifugal fan design code was developed and included in $DasignFan^{TM}$. This program generates forward -curved and backward-curved bladed centrifugal fan data. With the inverse design concept used in the code, the period of designing a fm, which has given aerodynamic performance with minimal acoustic noise, is significantly shortened.. A centrifugal fan design code, developed in this study and included in $DasignFan^{TM}$, predicts the aerodynamic performance by using mean-line analysis and various loss models. In the period of design a lift force distribution between pressure side and suction side of blade is calculated. And then it is used to calculate steady loading noise from the impeller.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.6
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• pp.804-812
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• 1997

The present study has tested most of loss models previously published in the open literature and found an optimum set of empirical loss models for a reliable performance prediction of centrifugal compressors. In order to improve the prediction of efficiency curves, this paper recommends a modified parasitic loss model. Predicted performance curves by the proposed optimum set agree fairly well with experimental data for a variety of centrifugal compressors. The prediction method developed through this study can serve as a tool for preliminary design and assist the understanding of the operational characteristics of general purpose centrifugal compressors.

• Proceedings of the KSME Conference
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• 2000.11b
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• pp.434-440
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• 2000

This study is focused on the performance prediction and design of the centrifugal pump with optimum shape. Design and analysis of centrifugal pump rely on experience of designer due to many fluid mechanical and geometrical variables. In this study, a design method was developed with experimental factors and analysed the method by comparition with 2nd-order vortex panel method. Impeller is the most important component affecting the performance of the centrifugal pump. The predicted total head for three cases, of which designs were determined by this method, agrees well with a particular commercial pump. This study shows that satisfactory performance of an optimal pump shape can be obtained through the automatic design routine.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.655-659
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• 2001

Resident time of the continuous and Instantaneous centrifugal separator using that separates the light and heavy liquids by use of density difference is the orptical factor that affects significantly the chemical metial extraction and the productivity in the chemical and mechanical process. In this paper, the overflow of the device is investigated under consideration of the relationships between inclination angle of liquid feeding screw and the centrifugal force. From the design of the length of a centrifugal separator, the radiuses of rotor and housing, theoretical formulation on the contact radius of separation weir is established through the experiments. From the experiments, it is identified that how much the capacity of inlet impeller and the emulsion phenomenon depend on the screw angle of inlet impeller. Also, we investigate the separation condition and the resident times that are functions of the phase ratio and density.

• International journal of advanced smart convergence
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• v.9 no.1
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• pp.10-18
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• 2020

In the case of a belt-pulley type CVT that transmits a driving force by using a variable pulley and a metal belt, slippage occurs due to transmission of power by using a belt, which results in a decrease in efficiency. Therefore, in this study, the rails were machined on the plate surface of the pulley to reduce the friction and slip between the belt and the pulley while applying the characteristics of the CVT. As the plate is rotated by the shape of the rail, a centrifugal belt pulley type continuously variable transmission system which shifts while varying the radius of rotation of the belt that transmits power is studied. Accordingly, the structure of the pulley was designed and the centrifugal belt pulley type continuously variable transmission was Manufactured. In addition, to verify the suitability of the manufactured transmission, the power transmission efficiency was monitored by establishing an interface with the controller. The structural analysis of the plate proved the suitability of the centrifugal belt pulley type continuously variable transmission.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.381-385
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• 2009

This paper describes performance characteristics of a centrifugal fan having a different volute casing. The centrifugal fan has a backward blade type, and is used in a refuse collecting system. The flow characteristics inside the components are analyzed by three-dimensional Navier-Stokes analysis, and also compared to the results by experiments. Distributions of pressure and efficiency obtained by numerical simulation has a good agreement with the experimental results. Throughout the numerical simulation of the centrifugal fan, a fan efficiency is increased by decreasing local losses in the blade passage. It is found that the fan efficiency is enhanced by decreasing the distance between the shroud of a impeller and casing. Detailed flow analysis is also analyzed and discussed using the results obtained by numerical simulation.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11a
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• pp.529-535
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• 2001

A centrifugal fan design code was developed and packaged together with iDesignFan／sup TM／ as new models. This code generate centrifugal forward curved and backward curved bladed impeller optimally. It also predicts the aerodynamic performance and the overall sound pressure level of the rotating fan by assuming steady blade loading. The overall sound pressure level is used as an input parameter from the third loop of the designing process to acquire the most silent fan for the given aerodynamic performance parameters. With this kind of inverse design concept used in the code, the period of designing a fan is significantly shortened. A centrifugal fan design code, developed in this study and included in iDesignFan／sup TM／, predicts the aerodynamic performance such as design flow rate and static pressure. The aerodynamic performance in the design and off-design conditions is calculated by using the mean line analysis. For the steady loading calculation, the lift force distribution in a blade is used.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.2
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• pp.376-381
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• 2004

A rig was constructed to test the performance characteristics and compare the hydraulic forces exerted on a centrifugal type artificial heart impeller. A conventional shaft. seal and bearing system. while driven by a small electric motor. supported the impeller which was separated from the pump casing by a six degree of freedom force transducer (JR3 Ine). Radial (x. y) and axial (z) hydraulic forces were recorded and compared. At physiological operating conditions. the results indicate that the double entry/exit centrifugal pump encounters a smaller radial force and significantly reduced axial thrust. These experimental results are valuable in the design of a magnetic bearing system to suspend the impeller of a centrifugal artificial heart pump. This experimental technique may also be applied to evaluate the required capacity and predict the lifetime of contact bearings in marine pumps.