• Title/Summary/Keyword: 공력 최적화

Search Result 96, Processing Time 0.039 seconds

Study on Optimization of Aerodynamic Design of A Jet Fan (제트송풍기의 공력설계 최적화에 관한 연구)

  • Seo, Seoung-Jin;Kim, Kwang-Yong;Chang, Dong-Wook
    • 유체기계공업학회:학술대회논문집
    • /
    • 2002.12a
    • /
    • pp.439-443
    • /
    • 2002
  • In this study, three-dimensional incompressible viscous flow analysis and optimization using response surface method are presented for the design of a jet fan. Steady, incompressible, three-dimensional Reynolds averaged Wavier-Stokes equations are used as governing equations, and standard k-$\epsilon$ turbulence model is chosen as a turbulence model. Governing equations are discretized using finite volume method. Sweep angles and maximum thickness of blade are used as design variables for the shape optimization of the impeller in response surface method. The experimental points which are needed to construct response surface are obtained from the D-optimal design and Full Factorial design and relations between design variables and response surface are examined.

  • PDF

AERODYNAMIC ANALYSIS AND OPTIMIZATION STUDY OF THE HELICOPTER ROTOR BLADE IN HOVERING FLIGHT (정지비행시 헬리콥터 로터 블레이드의 공력해석 및 최적화)

  • Je, S.E.;Jung, H.J.;Kim, D.J.;Joh, C.Y.;Myong, R.S.;Park, C.W.;Cho, T.H.
    • 한국전산유체공학회:학술대회논문집
    • /
    • 2007.04a
    • /
    • pp.125-129
    • /
    • 2007
  • In this paper a method for the design optimization for helicopter rotor blade in hover is studied Numerical analysis of aerodynamic characteristics of the flow around a rotor blade is analysed by usign panel method and CFD code based on Navier-Stokes equation. The result is validated by comparing with existing experimental result. Optimization methods RSM(Response Surface Method) and DOE(Design of Experiments) are applied in combination. The object functions are power, twist angle, taper ratio, and thrust. The optimized result showed a decrease of 17% of the power required.

  • PDF

Flutter Optimization of Composite Curved Wing Using Genetic Algorithms (유전자 알고리즘을 이용한 복합재료 곡면날개의 플러터 최적화)

  • Alexander, Boby;Kim, Dong-Hyun;Lee, Jung-Jin
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2006.05a
    • /
    • pp.696-702
    • /
    • 2006
  • Flutter characteristics of composite curved wing were investigated in this study. The efficient and robust system for the flutter optimization of general composite curved wing models has been developed using the coupled computational method based on both the standard genetic algorithm and the micro genetic algorithms. Micro genetic algorithm is used as an alternative method to overcome the relatively poor exploitation characteristics of the standard genetic algorithm. The present results show that the micro genetic algorithm is more efficient in order to find optimized lay-ups for a composite curved wing model. It is found that the flutter stability of curved wing model can be significantly increased using composite materials with proper optimum lamination design when compared to the case of isotropic wing model under the same weight condition.

  • PDF

Cruise Missile Configuration Optimal Design Using Multidisciplinary Analysis (다분야통합 해석을 이용한 순항미사일 형상 최적설계)

  • Choi, Suk-Min;Lee, Seung-Jin;Lee, Jae-Woo;Byun, Young-Hwan
    • Proceedings of the Korean Society of Propulsion Engineers Conference
    • /
    • 2007.04a
    • /
    • pp.38-42
    • /
    • 2007
  • In this study, cruise missile configuration is optimal designed by using multidisciplinary analysis. Aerodynamic, weight, performance and mission analysis modules are developed by FORTRAN and integrated with framework. Darwin algorithm, a global optimization tool, is used for optimization. In the result of optimal design, gross weight of designed configuration is reduced about 17% than baseline configuration while satisfying design constraint conditions.

  • PDF

MULTI-STAGE AERODYNAMIC DESIGN OF AIRCRAFT GEOMETRIES BY KRIGING-BASED MODELS AND ADJOINT VARIABLE APPROACH (Kriging 기반 모델과 매개변수(Adjoint Variable)법을 이용한 항공기형상의 2단계 공력최적설계)

  • Yim, J.W.;Lee, B.J.;Kim, C.
    • 한국전산유체공학회:학술대회논문집
    • /
    • 2009.04a
    • /
    • pp.57-65
    • /
    • 2009
  • An efficient and high-fidelity design approach for wing-body shape optimization is presented. Depending on the size of design space and the number of design of variable, aerodynamic shape optimization process is carried out via different optimization strategies at each design stage. In the first stage, global optimization techniques are applied to planform design with a few geometric design variables. In the second stage, local optimization techniques are used for wing surface design with a lot of design variables to maintain a sufficient design space with a high DOF (Degree of Freedom) geometric change. For global optimization, Kriging method in conjunction with Genetic Algorithm (GA) is used. Asearching algorithm of EI (Expected Improvement) points is introduced to enhance the quality of global optimization for the wing-planform design. For local optimization, a discrete adjoint method is adopted. By the successive combination of global and local optimization techniques, drag minimization is performed for a multi-body aircraft configuration while maintaining the baseline lift and the wing weight at the same time. Through the design process, performances of the test models are remarkably improved in comparison with the single stage design approach. The performance of the proposed design framework including wing planform design variables can be efficiently evaluated by the drag decomposition method, which can examine the improvement of various drag components, such as induced drag, wave drag, viscous drag and profile drag.

  • PDF

Aerodynamic Performance for Horizontal Axis Wind Turbine Model using Subsonic Wind Tunnel (풍동실험을 통한 수평축 풍력터빈 모델의 공력성능 연구)

  • Ryu, Ki-Wahn;Yoon, Seong-Jun;Lee, Chang-Su;Choy, Seong-Ok
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.35 no.11
    • /
    • pp.964-972
    • /
    • 2007
  • Wind turbine experiment was carried out for the horizontal axis wind turbine with the aerodynamically optimized blade. From the comparison of aerodynamic performance between upwind and downwind type wind turbine rotor, the measured torque fluctuation of the latter is larger than that of the former. This phenomenon is owing to the interaction of wake generated from support column and blades. The wind turbine model satisfies the design condition in that the measured result of the power coefficient at zero pitch angle shows maximum peak at the designed tip speed ratio, λ = 6. It also shows that the decrease in aerodynamic power due to negative pitch change is more sensitive than that of the same positive pitch change.

Aerodynamic Shape Optimization of Helicopter Rotor Blades in Hover Using a Continuous Adjoint Method on Unstructured Meshes (비정렬 격자계에서 연속 Adjoint 방법을 이용한 헬리콥터 로터 블레이드의 제자리 비행 공력 형상 최적설계)

  • Lee, S.-W.;Kwon, O.-J.
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.33 no.1
    • /
    • pp.1-10
    • /
    • 2005
  • An aerodynamic shape optimization technique has been developed for helicopter rotor blades in hover based on a continuous adjoint method on unstructured meshes. The Euler flow solver and the continuous adjoint sensitivity analysis were formulated on the rotating frame of reference for hovering rotor blades. In order to handle the repeated evaluation of the design cycle efficiently, the flow and adjoint solvers were parallelized using a domain decomposition strategy. A solution-adaptive mesh refinement technique was adopted for the accurate capturing of the tip vortex. Applications were made for the aerodynamic shape optimization of Caradonna-Tung rotor blades and UH60 rotor blades in hover. The results showed that the present method is an effective tool to determine optimum aerodynamic shapes of rotor blades requiring less torque while maintaining the desired thrust level.

Development of an aerodynamic design program for a small wind turbine blade (소형풍력발전기용 블레이드 공력설계 프로그램 개발)

  • Yoon, Jin-Yong;Paek, In-Su;Yoo, Neung-Soo
    • Journal of the Korean Solar Energy Society
    • /
    • v.33 no.1
    • /
    • pp.40-47
    • /
    • 2013
  • An aerodynamic design tool was developed for small wind turbine blades based on the blade element momentum theory. The lift and drag coefficients of blades that are needed for aerodynamic blade design were obtained in real time from the Xfoil program developed at University of Illinois. While running, the developed tool automatically accesses the Xfoil program, runs it with proper aerodynamic and airfoil properties, and finally obtains lift and drag coefficients. The obtained aerodynamic coefficients are then used to find out optimal twist angles and chord lengths of the airfoils. The developed tool was used to design a wind turbine blade using low Reynolds number airfoils, SG6040 and SG6043 to have its maximum power coefficient at a specified tip speed ratio. The performance of the blade was verified by a commercial code well known for its prediction accuracies.

A Study on the Mechanical Properties Optimization of Solid Propellant (고체 추진제의 기계물성 최적화 연구)

  • Choi, Yongkyu;Ryu, Taeha;Kim, Nakhyun;Kim, Jeongeun
    • Journal of the Korean Society of Propulsion Engineers
    • /
    • v.19 no.6
    • /
    • pp.91-97
    • /
    • 2015
  • The limit values of mechanical properties(MPs) of HTPB/AP/Al Solid Propellant was reviewed according to the rocket motor development procedures and the in-process values of MPs were analyzed by the tool of Process Capability Index. Based on finding the dependency among MPs, the optimization is proposed for reducing the properties defects and for improving the rocket grain safeties.

Dynamic Stall Control Using Aerodynamic Sensitivity Analysis (민감도 해석을 이용한 동적실속 제어)

  • Ahn, Tai-Sul;Kim, Hyoung-Jin;Kim, Chong-Am;Rho, Oh-Hyun
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.30 no.8
    • /
    • pp.10-20
    • /
    • 2002
  • The present paper investigates methods to control dynamic stall using an optimal approach. An unsteady aerodynamic sensitivity analysis code is developed by a direct differentiation method from a two-dimensional unsteady compressible Navier-Stokes solver including a two-equation turbulence model. Dynamic stall control is conducted by minimizing an objective function defined at an instant instead of integrating for a period of time. Unsteady sensitivity derivatives of the objective function are calculated by the sensitivity code, and optimization is carried out using a linear line search method at every physical time step. Numerous examples of dynamic stall control using control parameters such as nose radius, maximum thickness of airfoil, or suction show satisfactory results.