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Changwon, South Korea

Watanabe S.,Kyushu University | Uchinono Y.,Kyushu University | Ishizaka K.,Kyushu University | Furukawa A.,Oita National College of Technology | Kim J.-H.,Hyosung Goodsprings Inc.
Journal of Thermal Science | Year: 2013

It has been found in our past studies that the installation of asymmetric plate at the inlet of inducer is effective for the suppression of cavitation surge phenomenon. In the present study, the suction performance of 2-bladed helical inducer with an inlet asymmetric plate is experimentally investigated. It is observed that the suction performance in large flow rate conditions is not significantly influenced by the asymmetric plate, whereas the head of inducer with the asymmetric plate increases just before the head breakdown in partial flow conditions. To understand the mechanism of this additional head, the flow measurements and the numerical simulations are carried out. It is found that the circumferential component of absolute velocity at the exit of inducer slightly increases with the development of cavitation in both cases with and without the inlet asymmetric plate, indicating the increase of the theoretical head. The theoretical head increase with the inlet asymmetric plate is also confirmed by the unsteady numerical simulations, suggesting that the additional head is achieved through the increase of the theoretical head with the change of the exiting flow from the inducer associated with some amount of cavitation. © 2013 Science Press, Institute of Engineering Thermophysics, CAS and Springer-Verlag Berlin Heidelberg. Source

An Y.S.,Gyeongsang National University | Gu D.S.,Hyosung Goodsprings Inc. | Lee J.M.,Gyeongsang National University | Ha J.M.,Gyeongsang National University | And 4 more authors.
Journal of Mechanical Science and Technology | Year: 2014

The application of the high-frequency acoustic-emission (AE) technique in the condition monitoring of rotating machinery has been increasing of late. It has a major drawback, though, the attenuation of the signal, and as such, the AE sensor has to be close to its source. Two signal-processing methods, envelope analysis and wavelet transform, were found to be useful for detecting faults in the rolling element bearing and gearboxes. These methods have a disadvantage, though: their application is focused only on a component of the assembled machine. For example, envelope analysis is a powerful method for detecting faults in the bearing system, but it is not proper for use in the gear system. Thus, these methods could not be used to detect combined faults in the common assembled machines. Therefore, we propose a signal-processing method consisting of envelope analysis and DWT (discrete wavelet transform). In addition, a novel mother function optimized for the AE signal for DWT was extracted through a fatigue crack growth test, and is also proposed herein. Then the proposed method, called intensified envelope analysis (IEA), was used to detect the faults in the rolling element bearing and rotating shaft. According to the results, IEA can be a better signal processing method for the condition monitoring system using AE technique. © 2014, The Korean Society of Mechanical Engineers and Springer-Verlag Berlin Heidelberg. Source

Hyosung Goodsprings Inc. | Date: 2011-10-25

A flow path switching valve includes a tube body including one or more inlets opened to communicate with a fluid supplying source and supplying fluid into an inside of the tube body, outlets opened at opposite sides to the respective inlets and selectively alternately discharging fluid from the inside of the tube body, drains opened at opposite ends and discharging operating fluid introduced through the outlet, and seat units respectively protrude on an inner circumference of the tube body between the inlet(s), outlets and drains. An operating rod, coaxially mounted in the tube body, includes spaced apart projection units and is connected to an operating unit at one end so as to reciprocate axially within the tube body responsive to the operating unit. Valve bodies are movably disposed on an outer circumference of the operating rod and are arranged between the respective projection units to face respective seat units.

Kim Y.,Korea Institute of Construction Technology | Kang M.G.,Hyosung Goodsprings Inc. | Lee S.,Kookmin University | Jeon S.G.,Hyosung Goodsprings Inc. | Choi J.-S.,Korea Institute of Construction Technology
Desalination and Water Treatment | Year: 2013

Of paramount importance, seawater desalination plants using reverse osmosis (RO) is reducing the use of energy, which is mostly required for high pressure pumps. Accordingly, energy recovery devices (ERDs) are widely used for reusing hydraulic energy in RO concentrate stream. Nevertheless, few works have been done to investigate the operation characteristics of various EDR systems in actual desalination plants. In this context, we focused on the comparison of ERDs in a pilot plant with the capacity of 1,000m3/day. One centrifugal ERD (turbocharger) and two different types of isobaric ERDs (pressure exchanger [PX] and pressure exchanger for energy recovery [PEER]) were installed and tested under various conditions. Operation data in the pilot plant were analyzed to estimate specific energy consumption and energy transfer efficiency. The specific energy consumption analysis results showed that the isobaric ERDs have higher efficiency than the centrifugal ERD as also expected in theoretical estimation. The energy transfer efficiencies for PX and PEER were determined to be similar in short-term tests. © 2013 Desalination Publications. Source

Kang W.-T.,Changwon National University | Yu K.H.,Hyosung Goodsprings Inc. | Lee S.Y.,Hyosung Goodsprings Inc. | Shin B.R.,Changwon National University
ASME-JSME-KSME 2011 Joint Fluids Engineering Conference, AJK 2011 | Year: 2011

A numerical and an experimental investigation on a suction vortices including cavitation, free vortices and subsurface vortices behavior in the model sump system with multi-intakes is performed at several flow rates and water levels. A test model sump and piping system were designed based on Froude similitude for the prototype of the recommended structure layout by HI-9.8 American National Standard for Pump Intake Design of the Hydraulic Institute. An experiment is performed according to the sump model test procedure of Hyosung Goodsprings, Inc. A numerical analysis of three dimensional multiphase flows through the model sump is performed by using the finite volume method of the CFX code with multi-block structured grid systems. A k-ω Shear Stress Transport turbulence model and the Rayleigh-Plesset cavitation model are used for solving turbulence cavitating flow. Several types of free surface and submerged vortex which occurs with each different water level are identified through the experimental investigation. From the numerical analysis, the vortices are reproduced and their formation, growing, shedding and detailed vortex structures are investigated. To reduce abnormal vortices, an anti-vortex device is considered and its effect is investigated and discussed. Copyright © 2011 by ASME. Source

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