• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.444-447
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• 2009

The optimum design and the performance analysis software called POSEIDON for the HAWT (Horizontal Axis Wind Turbine) was developed by use of BEMT. The Prandtl's tip loss theory was adopted to consider the blade tip loss. The aerodynamic characteristics of NACA 63415 airfoils were predicted via X-FOIL and the post stall characteristics were estimated by the Viterna's equations. All the predicted aerodynamic characteristics are fairly well agreed with the Velux wind tunnel test results. The rated power of the testing rotor is 5kW at design conditions. The power, estimated by use of predicted lift and drag coefficient via X-FOIL becomes a little higher than experimental one.

• Journal of Advanced Marine Engineering and Technology
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• v.31 no.4
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• pp.356-362
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• 2007

The optimum design and the performance analysis software called POSEIDON for the HAWT (Horizontal Axis Wind Turbine) was developed by use of BEMT. The Prandtl's tip loss theory was adopted to consider the blade tip loss. The aerodynamic characteristics of NACA 63-415 airfoils were predicted via X-FOIL and the post stall characteristics were estimated by the Viterna's equations. All the predicted aerodynamic characteristics are fairly well agreed with the Velux wind tunnel test results. The rated power of the testing rotor is 1 kW at design conditions. The power, estimated by use of predicted lift and drag coefficient via X-FOIL becomes a little higher than experimental one.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.901-902
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• 2006

In high-speed PM machines, rotor losses form a larger proportion of the total losses than usual in conventional low speed machines. In order to maintain the mechanical integrity of a high-speed PM rotor intended for high-speed operation, the rotor assembly is often retained within a sleeve or can. The sleeve is exposed to field produced by the stator from either the slotting or the mmf harmonics that are not synchronous with the rotor. These non-synchronous fields cause the significant rotor losses. An optimum design of high-speed PM machines requires the accurate prediction for these rotor losses. On the basis of analytical field analysis and 2D finite element analysis (FEA), this paper deals with the rotor losses.

• Solar Energy
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• v.20 no.3
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• pp.75-84
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• 2000

The purpose of this research is to study on the heat transfer characteristics of separate type heat pipe with a rotor. The heat transfer characteristics of the rotor condenser are various on input heat of evaporator, rotational speeds of rotor, and working fluid amount. The results obtained from the study are as follows. 1. Magnetic fluid using seal of the rotor operated in stability by a variation of temperature and rotation speeds. The configuration of magnetic fluid seal assembly was adequate. 2. Steam ejector is effective in recovering working fluid condensate in the rotor. When steam ejector is operating, the heat flux of working fluid does not change, with the wall temperature in the rotor. 3. The optimum design conditions on working fluid amount and rotational speeds are effective in evaporator volume 50%, rotational speeds 200rpm, 300rpm, and operating temperature $80^{\circ}C$. With working fluid amount increasing, overall heat transfer coefficient decreases linearly.

• Proceedings of the KIEE Conference
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• 2005.04a
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• pp.114-116
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• 2005

This paper deals with an automatic design standard computation based on a rated watt for a synchronous reluctance motor (SynRM). The focus of this paper is mating the design relative to the output rover on the basis of rotor shape of a SynRM in each rated watt using a coupled FEM & sequential unconstrained minimization technique (SUMT). The coupled finite elements analysis (FEA) & Preisach model have been used to evaluate nonlinear solutions. The proposed procedure allows to define the rotor geometric dimensions according to the rotor diameter and rated watt starting from an existing motor or a preliminary design.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1095-1097
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• 2005

This paper deals with an automatic design standard computation based on a rated watt for a synchronous reluctance motor(SynRM). The focus of this paper is making the design relative to the output power on the basis of rotor shape of a SynRM in each rated watt using a coupled FEM & sequential unconstrained minimization technique(SUMT). The coupled finite elements analysis(FEA) & Preisach model have been used to evaluate nonlinear solutions. The proposed procedure allows to define the rotor geometric dimensions according to the rotor diameter and rated watt starting from an existing motor or a preliminary design.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.972-975
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• 2004

In order to reduce the noise of BLDC motor, a systematic optimization procedure for rotor structure is presented. The noise index is defined as the sum of volume velocity of FE-model that are calculated at the dominant frequencies during dehydration process, which is based on the principle of radiation simple volume source. Then, the five design variables are selected to represent the shape and layout or rotor structure. This discrete design optimization problem for minimizing the noise index is solved by 3-level orthogonal array based effect analysis. Finally, the response surface method (RSM) combined optimization approach is employed for more refining the approximate optimum.

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.407-410
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• 2002

A three-phase 6/8 structure Switched Reluctance Motor drive, the construction of the stator and the rotor. in the motor, the scheme of the rotor position detector and the main circuit of the power converter are described. The range of the stator pole arc factor and the rotor pole arc factor of the motor are analyzed in the linear region. The optimum range of the stator pole arc factor and the optimum range of the turn-off angle of the main switches in the power converter are given with the 2-D finite element electro-magnetic field calculation of the motor and the nonlinear simulation. Test jesuits of the developed prototype are discussed.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.9
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• pp.1292-1301
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• 2002

An experimental study of turbine performance is conducted with various incidence angles on a rotating turbine rotor. 5 different incidence angles are applied from -17$^{\circ}$to 13$^{\circ}$with 7.5$^{\circ}$gaps. In order to precisely set up the incidence angles at the rotor inlet, 5 turbine discs are manufactured with the different fir tree section. Total-to-total efficiencies are obtained on the several off-design points with considering the exit total pressure, which is meas fred at 12 locations between the hub and casing using a pressure rake. The degree of reaction is 0.373 at the mean radius, and Reynolds number based on the rotor chord is 0.86$\times$10$^{5}$ at the turbine inlet on the design point experiment. The experiment on a single-stage turbine is conducted at the low-pressure and low-speed state, but it is sufficient to consider the blade loading effect due to the rotating apparatus even though the total pressure loss at the exit is increased proportionally to the turbine output power. The experimental results recommend 6$^{\circ}$as an optimum incidence angle on the turbine blade design. The total-to-total efficiency is steeply decreased when the incidence angle is over $\pm$9$^{\circ}$ from the optimum incidence angle. In the range of less than -10$^{\circ}$incidence angle, 7.5$^{\circ}$ reduction of incidence angle generates 15% decrease of total-to-total efficiency. This result is obtained on the same rotor blade by changing only the rotational speed to minimize the effect of profile and secondary flow loss in the passage. Experimental results show that the change rate of total-to-total efficiency according to the incidence angle change is unchanged although the turbine operates at the off-design condition.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.1222-1227
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• 2000

The optimization study are carried out for helicopter rotor blades with composite box-beam spar. The objective function is to minimize the weight of rotor blades subject to frequency, aeroelastic stability and failure constraints. Design variables include the number of ply and ply angles of the laminated walls. The beam model of a hinge less rotor blade is based on a large deflection beam theory to describe the arbitrary large deflections and rotations. The p-k method and unsteady two dimensional strip theory are used to calculate aeroelastic stability boundary.