• 유체기계공업학회:학술대회논문집
• /
• 2002.12a
• /
• pp.250-257
• /
• 2002

A centrifugal compressor for HFC-l34a has been newly designed and developed. Flow analysis using commertial programs was used to evaluate performance and internal flow of the impeller, inlet guide vane and diffuser etc. and design software was developed. The compressor for HFC-l34a was also investigated experimentally to check compression performance. The calculated data coincide the test results of compressor. The data obtained in the present study are useful for design of HFC-l34a centrifugal compressors.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2011.10a
• /
• pp.625-626
• /
• 2011

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2008.03a
• /
• pp.915-915
• /
• 2008

• 유체기계공업학회:학술대회논문집
• /
• 2006.08a
• /
• pp.331-334
• /
• 2006

Air foil bearings have been attempted for application to industrial turbo machines, since they have several advantages over oil bearings in terms of endurance, simplicity, environment-friendliness, efficiency, sound and vibration, and small turbo machines with air foil bearings are in the market as the result. Recently, researches on widening the application spectrum of air foil bearings are in progress worldwide. In this paper, a 300 HP class turbo blower using air foil bearings is introduced. The turbo blower has a high speed PMSM(Permanent Magnet Synchronous Motor) driving a compressor, and air flow rate is designed to be $180\;m^3/min$ at pressure ratio of 1.6. The maximum rotational speed is set to 17,000 RPM to maximize the total efficiency with the result that the weight of rotor assembly is 26kg, which is expected to be the largest turbo machine with air foil bearings ever developed in the world.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2010.11a
• /
• pp.101-104
• /
• 2010

Recently, needs for UAVs and small aircraft and small turbo jet or turbo fan engines for these air-crafts are increasing. Size and weight are the two main restrictions in small air-crafts such as UAV or VLJ propulsion system applications. Therefore, high power density is required in small size and designers come up with unconventional solutions in the design of small aero gas turbine engines. One of the solutions is the usage of highly loaded axial compressors. This paper introduces an aerodynamic design method of a highly loaded axial compressor and its review process. Numerical simulation has been carried out to assess the aerodynamic performance of the compressor.

• 유체기계공업학회:학술대회논문집
• /
• 2003.12a
• /
• pp.323-323
• /
• 2003

Many recent development activities suggest the possibility of a high-speed turbo(centrifugal) compressor or blower for the industrial application of compressed air supplying system when used with the most advanced high-speed motor, inverter technology, and advanced bearing for high rotational speed. The problems to be overcome are of reliability, the application of mass production methods, cost effective manufacture and competitive running costs. This presentation is not focused on a specific technology advances but on an overall review of our recent experiences while we have developed the high pressure turbo blower for the commercial purpose.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.24 no.8
• /
• pp.583-591
• /
• 2014

The mathematical modeling on the free vibration and stability of a multi-stepped shaft of turbo compressor is performed in this study. The multi-stepped shaft is modeled as a non-uniform Timoshenko beam supported by anisotropic bearings. It is assumed that the shaft is spinning with constant speed about its longitudinal axis and subjected to a conservative axial force induced by front and rear impellers attached to the shaft. The structural model incorporates non-classical features such as transverse shear and rotary inertia. A structural coupling between vertical and lateral motions is induced by Coriolis acceleration terms. The governing equations are derived via Hamilton's variational principle and the equations are transformed to the standard form of an eigenvalue problem. The implications of combined gyroscopic effect, conservative axial force, bearing stiffness and damping are revealed and a number of pertinent conclusions are outlined. In this study analytical results are compared with those from ANSYS finite element analysis and experimental modal testing.

• International Journal of Fluid Machinery and Systems
• /
• v.2 no.4
• /
• pp.409-417
• /
• 2009

An investigation of surge inception in a centrifugal compressor was done with measurements of steady and unsteady static pressure. Vaneless diffuser and vaned diffuser were tested. Analyses of the static pressure and the pressure fluctuation showed that stall at the impeller leading edge occurred at first, and then it extended to downstream. In case of the vaneless diffuser, deterioration of the pressure rise in the impeller triggered instability. For the vande diffuser, instability that was generated in the impeller propagated into the vaned diffuser, however the pressure recovery by the vaned diffuser made the operation of the compressor stable at low flow rate.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2008.03a
• /
• pp.213-217
• /
• 2008

This paper describes an application of centrifugal compressor optimization system, in which the blade profile of impeller is represented with NURBS(Non-Uniform Rational B-Spline) curve. A commercial CFD(Computational Fluid Dynamics) program named NUMECA fine/turbo was used to evaluate the performance of the whole centrifugal compressor flow passage including impeller and diffuser. The whole optimization design system was integrated based on iSIGHT, a commercial integration and optimization software, which provides a direct application of some optimization algorithms. To insure the practicability of optimization, the performance of centrifugal compressor under all condition was concerned during the optimizing process. That means a compositive object function considering the aerodynamic efficiency, pressure ratio and mass flow rate under different work condition was applied by using different weight number for different conditions. Using the optimization method described in this paper, an optimized design of the impeller blade of centrifugal compressor was obtained. Comparing to the original design, optimized design has a better performance not only under the design work condition, but also the off-design work condition including near stall and near choke condition.

• Journal of Advanced Marine Engineering and Technology
• /
• v.24 no.5
• /
• pp.76-85
• /
• 2000

Stirling cycle was actualized as so called ‘hot air engine’. It has been focused again lately as one of measures for exhaust gas emission problem, but as small power engine because of its method of heat addition. Recently marine power plants commenced to meet a stringent environmental restrictions by international convention, Marpol so that diesel engines as main and auxiliarly power plants are urged to be reformed to reduce NOx emission. Author devised a compression ignition engine as a large marine power plants combined with turbo charger based on stirling cycle, and analyzed the performance by means of basic thermodynamic calculation. Analyzed in this paper, were theoretical efficiency, mean effective pressure, required equivalence ratio, gas turbine power ratio, maximum pressure, states of turbo-charger inlet gas and exhaust gas, manifesting that the engine could be proposed as one of the future power plants of marine use.