• 유체기계공업학회:학술대회논문집
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• 2000.12a
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• pp.187-192
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• 2000

The effects of diffuser shapes on the flowfields of a small-size turbo-compressor have been investigated by numerically and experimentally. It is important to optimal design of each elements for developing the small-size turbo-compressor Typical range of rotating speed of a small-size turbo-compressor is 40,000-70,000rpm. Numerical analyses are conducted to the rectangular and conical shapes of diffusers. Three-dimensional, steady, viscous governing equations are solved by SIMPLE algorithm. To prove the numerical results, experimental studies for the measurements of static pressure and temperature at the inlet and outlet boundaries are performed. Comparisons of these results are executed, and reasonable agreements are acquired.

• The KSFM Journal of Fluid Machinery
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• v.4 no.3 s.12
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• pp.21-28
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• 2001

The effects of diffuser shapes on the flowfields of a small-size turbo-compressor have been investigated numerically and experimentally. The optimal design of elements shapes is important to develop the high efficiency turbo-compressor. Typical range of rotating speed for a small-size turbo-compressor is 40,000-70,000rpm. Numerical analyses were conducted to the rectangular and conical shapes of diffuser Three-dimensional, steady and viscous governing equations were solved by SIMPLE algorithm. To confirm the numerical results, the experimental measurements for the static pressure and temperature at the inlet and outlet boundaries were performed. Comparisons of these results were done, and the reasonable agreements were acquired.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.777-782
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• 2000

The flow fields in the volute casing of a small-size turbo-compressor at different flowrate (design point ${\pm}20%$) are studied by numerical analysis. The governing equations for three-dimensional steady viscous flow are solved using SIMPLE algorithm with commercial code of STAR-CD. Numerical results show that the three-dimensional flow pattern inside the volute casing of a small-size turbo-compressor is strongly influenced by secondary flows that are typically created by the curvature or the casing passages. The flow pattern in the casing also affects the performance of the turbo-compressor. In order to elucidate the loss mechanism through the volute, we prepared the secondary flow, velocity magnitude, and static pressure distribution at the four cross-sectional planes of the casing.

• 한국전산유체공학회:학술대회논문집
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• 2010.05a
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• pp.142-146
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• 2010

This study presents the design of small size turbo-compressor to increase the performance using computational fluid analysis. A three dimensional computation was conducted changing the main parameters of impeller blade and diffuser shape, respectively, and the design was performed on a basis analysis of result of that. As a result, the Improved shapes show the increase of efficiency in comparison with the existing shape. This study will be used as useful reference data to establish the design concept of the small size turbo-compressor and to improve its performance.

• 유체기계공업학회:학술대회논문집
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• 2001.11a
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• pp.120-125
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• 2001

The effects of various vaned diffuser configurations, such as throat area ratios and rectangular and conical cross-section shapes. to the performance of a small-size turbo-compressor are studied. Numerical analyses were carried out for the region of diffuser and casing only. The pressure recovery coefficient was calculated to estimate the performance of the diffuser, and then compared with the measured data. Results show that the shapes and the throat area ratios of the diffuser strongly influence on the performance of a turbo-compressor.

• Proceedings of the KSME Conference
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• 2001.06e
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• pp.813-818
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• 2001

The flow characteristics of the vaned diffuser were complicated with geometric shapes. We have studied the effects of various vaned diffuser configurations, such as divergence angles and rectangular and conical cross-section shapes. Numerical analyses are carried out for the diffuser and casing. The pressure recovery coefficient was calculated to estimate the performance of the diffuser, and then compared with the measure data. Results show that the shapes and the divergence angles of the diffuser strongly influence on the performance of the small-size turbo-compressor.

• Proceedings of the IEEK Conference
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• 2002.06e
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• pp.219-222
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• 2002

There are screw, reciprocating type turbo compressor by structure in an air compressor which is essential equipment on the industrial spot. Recently, the application range of a turbo compressor tend to be wide gradually. And this type of compressor needs high speed rotation of impeller in structure so high ratio gearbox and conventional induction motor driving required. This mechanical system have results of increased moment of inertia and mechanical friction loss. Recent studies of modern turbo compressor have been applied to developing super high speed BLDC motor and driver which remove gearbox that make its size small and mechanical friction loss minimum. To accomodate this tendency, we tried to develope a super high speed motor drive system for 150Hp, 70,000rpm direct drive Turbo compressor using DSP(Digital Signal Processor) and SVPWM(Space Vector Modulation PWM) technique. The results of this specific application show that super high speed driver and controller could be implemented well with digital electronics.

• Proceedings of the KSME Conference
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• 2001.06e
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• pp.807-812
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• 2001

The effects of casing shapes on the interaction of the impeller and volute in a small-size turbo-compressor are investigated. Numerical analysis is conducted for the compressor with circular and single volute casings from inlet to discharge nozzle. In order to predict the flow pattern inside the entire impeller, vaneless diffuser, and casing, calculations with a multiple frame of reference method between the rotating and stationery parts of the domain are carried out. For incompressible turbulent flow fields, the continuity and three-dimensional time-averaged Navier-Stokes equations are employed. To predict the performance of two types of casings, the static pressure and loss coefficients are obtained with various flow rates. Also, static pressure distributions around casings are studied for different casing shapes, which are very important to predict the distribution of radial load.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.6
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• pp.879-884
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• 2002

There are screw, reciprocating and turbo compressor by structure in an air compressor, essential equipment on he industrial spot. Resently it is wide that the range of turbo compressor's use in gradual, turbo compressor needs high speed rotation of impeller in structure, high rated gearbox and conventional induction motor. This mechanical system increased the moment of inertia and mechanical friction loss. Resently the study of turbo compressor applied super high speed motor and drive, removing gearbox made its size small and mechanical friction loss minimum. In this study we tried to develope variable super high speed motor drive systems for 150Hp, 70,000rpm drect drive Turbo compressor. The result of study is applied to a 150Hp direct turbo compressor and makes it goods.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.12
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• pp.1031-1038
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• 2002

The effects of casing shape on the performance and interaction between the impeller and casing in a small-size turbo-compressor are investigated. Numerical analysis is conducted for the compressor with circular and single volute casings from inlet to discharge nozzle. In order to predict the flow pattern inside the entire impeller, vaneless diffuer and casing, calculations with multiple frames of reference method between the rotating and stationery parts of the domain are carried out. For compressible turbulent flow fields, the continuity and three-dimensional time-averaged Wavier-Stokes equations are employed. To evaluate the performance of two types of casings, the static pressure and loss coefficients are obtained with various flow rates. Also, static pressure distributions around casings are studied for different casing shapes, which are very important to predict the distribution of radial load. To prove the accuracy of numerical results, measurements of static pressure around casing and pressure difference between the inlet and outlet of the compressor are peformed for the circular casing. Comparisons of these results between the experimental and numerical analyses are conducted, and reasonable agreement is obtained.