• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.1322-1325
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• 2009

The impeller and vane diffuser for the mixed flow pump(NS550) was designed by using meridional selection program and inverse design method. We decided the meridional shape of the impeller from the meridional design parameter, such as the specific speed and maximum diameter at the impeller exit. The meridional shape of vane diffuser was set from the impeller shape, distribution of cross sectional area and maximum diffuser diameter. The angle of impeller blade and diffuser vane was designed by using inverse design method. The predicted overall performance by using commercial CFD code(ANSYS CFX-11) shown good agreement with design goals.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11a
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• pp.504-511
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• 2001

In this research, we developed a computer program that designs a centrifugal impeller and diffuser, and predicts the far-field noise from the impeller. To design the impeller optimally, the TEIS model, which was originally developed by Japkise(1985), and the mean-line analysis are combined to predict the performance and design the optimal impeller simultaneously. The geometric configurations are provided by a GUI software (iDesignComp). The noise from impeller can be computed by the rapid loading procedure, which generates a surface between two blades and calculates the pressure distributions on the suction and pressure sides. The steady loading noise is computed by the rotating dipole source distribution via Ffowcs Williams & Hawkings equation.

• 유체기계공업학회:학술대회논문집
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• 1999.12a
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• pp.125-133
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• 1999

This paper reports the impeller performance of centrifugal pump, modified HES65-250. Developed CFD code uses SIMPLE algorithm, power-law scheme, standard k-$\epsilon$ turbulence model in curvilinear coordinate system. The calculations are conducted for 5 cases, from 0.6 to 1.4 of flow rate ratio with 0.2 increment. The flow characteristics inside of impeller are analysed. The results show that reversal flows exist at the inlet of impeller which have small rotary stagnation pressure. The obtained results are compared with the experimental data at impeller exit and shows good qualitative agreement.

• Journal of the Korean Society of Mechanical Technology
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• v.20 no.6
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• pp.757-762
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• 2018

LDV(laser Doppler velocimetry) measurements were conducted on the exit region of the impeller passage and the gap between the impeller and turbine blades under 0.8 speed ratio. The 0.8 speed ratio has an impeller speed of 2000rpm and a turbine speed of 1600rpm. A periodic variation of the mass flow rate is present in many of the measurements made. The frequency of this variation is the same as the frequency of the turbine blades passing the impeller passage exit. It is found that the instantaneous position of the turbine had effect on fluid flow inside the impeller passage and gap region. This study would aid in the construction of higher accuracy CFD models of this complex turbomachinery device.

• Journal of the Korean Society for Marine Environment & Energy
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• v.14 no.4
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• pp.230-238
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• 2011

The experimental study for the performances of 100 kW marine current turbines (Horizontal Axis Turbine) has been conducted with three cases of 700 mm diameter model in PNU 100 m towing tank. Three cases of impeller have been designed according to the variation of section configuration and tip shape. The model tests have been carried out at different speed of revolution to find out the scale effect (Reynolds number effect). The designed rake impeller was the best among them in the efficiency point of view especially at high Tip Speed Ratio (TSR). The present study is expected to be extended to conduct at high reynolds number as well as the computational study for the validation.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.12
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• pp.1201-1207
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• 2012

This study was performed to develop a high-efficiency submersible nonclogging pump impeller. Toward this end, we simulated the effect of some parameters such as the outlet position of a blade ($h_I$), outlet width of a blade ($b_2$), and hub profile on the pump efficiency by using the commercial codes ANSYS CFX and BladeGen. The results showed that the pump efficiency was proportional up to $h_I$= 38 mm and $b_2$= 55 mm. It remained constant over these values. However, the head and shaft power were proportional to $h_I$ and $b_2$ in the simulated ranges. The effects of hub profile changes on the pump efficiency were relatively small compared to those of the other parameters.

• The KSFM Journal of Fluid Machinery
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• v.18 no.4
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• pp.56-61
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• 2015

It is important requirement to properly evaluate the aerodynamic performance and characteristics during preliminary design of a centrifugal compressor. In this study the centrifugal compressor was calculated for variations of mass flow and blade Mach number by means of single passage steady state. A lot of quantitative performance values were obtained and through the obtained values the aerodynamic performance characteristics of designed impeller and vaned diffuser were investigated. The results were classified by blade Mach number to analyze characteristics and the aerodynamic performance was examined at choke of impeller, diffuser and separation of diffuser.

• The KSFM Journal of Fluid Machinery
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• v.17 no.3
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• pp.5-12
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• 2014

This paper presents a design optimization for meridional profile and blade angle ${\theta}$ of a centrifugal compressor with DOE (design of experiments) and RSM (response surface method). Control points of the $3^{rd}$ order Bezier curve are used for design parameters and specific overall efficiency is used as object function. The response surface function shows good agreement with the 3D computational results. Three different optimized designs are proposed and compared with reference design at design point and off-design point. Contours of relative Mach number, static entropy, and total pressure are analyzed for improvement of performance by optimization. Off-design performance analysis is conducted by total pressure and efficiency.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.3
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• pp.83-90
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• 2004

This paper proposes a tool path generation method for machining impellers with 5-axis machining center. The shape of impeller is complex, being composed of pressure surface, suction surface and leading edge, and so on. The compound surface which is made of ruled surface such as pressure surface and suction surface and leading edge such as fillet surface, makes the tool path generation much complicated. To achieve efficient roughing, cutting area is divided into two region and then tool radius of maximum size that do not cause tool intereference is selected for shortening machining time. In finishing, accuracy is improved using side cutting for blade surface and point milling for leading edge.

• Applied Chemistry for Engineering
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• v.16 no.5
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• pp.698-704
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• 2005

Power consumption for paddle impeller in spherical and cylindrical agitated vessel was measured over a wide range of Reynolds number from laminar to turbulent flow regions. The power correlation was obtained for both spherical and cylindrical vessels, where the apparent diameter of the spherical vessel was equal to the diameter of the cylindrical vessel (height equal to its diameter and had the same volume as the spherical vessel). The power consumption well correlated with the experimental results of Nagata, et al. and Hixson-Baum. Also the critical Reynolds numbers was directly related to the transition coefficient $C_{tr}$ characterizing the transition from a laminar to a turbulent flow region in the correlation proposed here.