• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.512-515
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• 2009

This research describes on airfoil shape design, crucial to core technique and algorithm optimization for the wind turbine blade development. We grasped the parameter to define the airfoil shape in the wind turbine blade and aircraft, and the important performance characteristic of the airfoil. The airfoil shape function is selected by studying which is suitable for wind turbine blade airfoil development. The selected method is verified by to compare the generated airfoil shape with base airfoil. The new airfoils were created by the selecting shape function based on the well-known airfoil for wind turbine blades. In addition, we performed aerodynamic analysis about the generated airfoils by XFOIL and estimated the point of difference in the airfoil shape parameter using the aerodynamic performance results which is compared with basic airfoil. This result data applies to the fundamental research for a wind turbine blade optimization design and accomplished the aerodynamic analysis manual.

• 유체기계공업학회:학술대회논문집
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• 2001.11a
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• pp.293-299
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• 2001

Since the previous cut-and-try design algorithm require much cost and time, it has recently been concerned the automatic design technique using the CFD and optimum design algorithm. In this study, the Navier-Stokes equations is solved to consider the more detail viscous flow informations of cascade interaction and O-H multiblock grid system is generated to impose an accurate boundary condition. The cubic-spline interpolation is applied to handle a relative motion of a rotor to the stator. To validate present procedure, the time averaged aerodynamic loads are compared with experiment and good agreement obtained. Once the N-S equations have been solved, the computed aerodynamic loads may be used to computed the sensitivities of the aerodynamic objective function. The Modified Method of feasible Direction(MMFD) is usef to compute the

• 한국전산유체공학회:학술대회논문집
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• 2010.05a
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• pp.50-54
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• 2010

In this study, reliability-based design optimizations of airfoils were performed. PARSEC function was used to consider the uncertainty of the aerodynamic shape for the reliability-based shape optimization of airfoils. Among aerodynamic performance. The accuracy of the reliability analysis was compared with other method and it was found that the moment method predicts the probability accurately. Deterministic and reliability-based optimizations were performed for shape of the RAE2822 airfoil and it was demonstrated that reliability-based optimizations the aerodynamic performances under uncertainties of the shape of the airfoil.

• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.183-189
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• 2016

In this paper, an optimization study on a helicopter rotor blade cross-section was made. Generalization was made to the baseline cross-section to simplify the analysis. To have better performance in aeroelastic response, with the aerodynamic center being the origin of the baseline, the distance between aerodynamic center and shear center, and the distance between mass center and shear center of the blade were minimized. For efficient searching of optimum solutions over the design space, grid search method, which is a method of graphical search was used. Two design variables, radius of balancing weight at leading edge, and offset of the spar from leading edge were selected for the study. Cubic spline interpolation method was used to accommodate searching of the optimum solution. 2-Leveled searching system was devised in accordance with the interpolation method. Optimum solution was found to show 6% decrease in both distance between aerodynamic center and shear center, and mass center and shear center to the baseline.

• Journal of computational fluids engineering
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• v.19 no.3
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• pp.29-36
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• 2014

In the present study, an aerodynamic design optimization of UAV rotor blades was conducted using a genetic algorithm(GA) coupled with computational fluid dynamics(CFD). To reduce computational cost in making databases, a function approximation was applied using artificial neural networks(ANN) based on a radial basis function network. Three dimensional Reynolds-Averaged Navier-Stokes(RANS) solver was used to solve the flow around UAV rotor blades. Design directions were specified to maximize thrust coefficient maintaining torque coefficient and minimize torque coefficient maintaining thrust coefficient. Design variables such as twist angle, thickness and chord length were adopted to perform a planform optimization. As a result of an optimization regarding to maximizing thrust coefficient, thrust coefficient was increased about 4.5% than base configuration. In case of an optimization minimizing torque coefficient, torque coefficient was decreased about 7.4% comparing with base configuration.

• The KSFM Journal of Fluid Machinery
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• v.15 no.6
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• pp.77-84
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• 2012

The aerodynamic performance of a single-stage transonic axial compressor was experimentally evaluated by measuring pressure and temperature distribution at the inlet and outlet of the compressor. The compressor was developed by Korea Aerospace Research Institute through multidisciplinary design optimization (MDO) method, especially integrating aerodynamic performance and structural stability. The test results show that the pressure ratio is 1.65 and the efficiency is 85.8 % at design point, where the corrected speed is 22,000 rpm and the corrected mass flow rate is 15.4 kg/s, and it has a good agreement with the design target and computational results. The distribution of pressure ratio is very steep at design speed, compared with the trend of other subsonic compressors. Also the static pressure distribution on the stator casing shows that the blade loading is gradually increasing through the stage as designed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.9-16
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• 2017

In this paper, the aerodynamic design process of wind turbine blades is established. The optimization design strategy is presented and the constraints that must be reviewed during the aerodynamic design process are summarized. Based on this, this study developed a BEMT-based aerodynamic optimal design program that can be applied easily to actual work, not only for research purposes, but also can be integrated from the initial concept design stage to the final 3D shape detail design stage. The developed program AeroDA consisted of a concept design module, basic design module, optimal TSR module, local shape optimization module, performance analysis module, design verification module, and 3D shape generation module. Using the developed program, an improved design of the 5MW blade by NREL was made, and it was confirmed that this program could be used for design optimization. In addition, a 10kW blade aerodynamic design and turbine detailed performance analysis were carried out, and it was verified by a comparison with the commercial program DNVGL Bladed.

• 한국전산유체공학회:학술대회논문집
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• 2008.03a
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• pp.227-228
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• 2008

In the present paper, fowler flap was optimized to maximize the lift with response surface method. Leading edge shape and the gap between main airfoil and flap, were optimized and the aerodynamic characteristics was improved considerably. The optimized flap has more rounded leading edge and bigger gap. Before angle of attack, $10^{\circ}$, lift and drag are improved and the optimized flap shows similar aerodynamic characteristics to the original flap. The flow condition for optimization was angle of attack, $10^{\circ}$, Mach number, 0.2, flap deflection, $40^{\circ}$.

• 한국전산유체공학회:학술대회논문집
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• 2004.10a
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• pp.181-186
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• 2004

In gradient based optimization methods, the finite differencing which uses small perturbations in the design variables has been used to calculate the sensitivity. Recently, the automatic differentiation has been widely studied to calculate the function value and the sensitivities simultaneously. In this paper, the applicability of the automatic differentiation In the aerodynamic design optimization is studied. ADIFOR and TAPENADE are used to generate the codes which give the function value and the sensitivities for 2D compressible inviscid flows.

• 한국전산유체공학회:학술대회논문집
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• 2008.10a
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• pp.227-228
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• 2008

In the present paper, fowler flap was optimized to maximize the lift with response surface method. Leading edge shape and the gap between main airfoil and flap, were optimized and the aerodynamic characteristics was improved considerably. The optimized flap has more rounded leading edge and bigger gap. Before angle of attack, $10^{\circ}$, lift and drag are improved and the optimized flap shows similar aerodynamic characteristics to the original flap. The flow condition for optimization was angle of attack, $10^{\circ}$, Mach number, 0.2, flap deflection, $40^{\circ}$.