• Title/Summary/Keyword: high-fidelity

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Numerical Study on the Premixed Flame Instability and Nonlinear Behavior (예혼합화염의 불안정성 및 비선형적 거동에 관한 수치적 연구)

  • Kang, Sang-Hun;Baek, Seung-Wook;Im, Hong G.
    • 한국연소학회:학술대회논문집
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    • 2005.10a
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    • pp.281-286
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    • 2005
  • To understand fundamental characteristics of combustion in a small scale device, the effects of the momentum and heat loss on the stability of laminar premixed flames in a narrow channel are investigated by two-dimensional high-fidelity numerical simulation. A general finding is that momentum loss promotes the Saffman-Taylor (S-T) instability which is additive to the Darrieus-Landau (D-L) instabilities, while the heat loss effects result in an enhancement of the diffusive-thermal (D-T) instability. These effects are also valid in nonlinear behavior of the premixed flame. The simulations of multiple cell interactions are also conducted with heat and momentum loss effects.

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Anthropometric Data Collection for MCR Environment Design of Nuclear Power Plant (원자력 발전소 환경 디자인 설계를 위한 인체측정에 대한 연구)

  • Cha, Woo Chang
    • Journal of the Korean Society of Systems Engineering
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    • v.6 no.1
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    • pp.47-52
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    • 2010
  • Human Factors Engineering (HFE) for Main Control Room (MCR) of Nuclear Power Plant (NPP) has been applied to optimize the design and operation of Man-Machine Interface (MMI) between operators and their equipment in consideration of physical, psychological and cognitive aspects. However, it has been observed that operators complain about environmental discomfort in the MCR since the operators in the MCR experience excessive stress due to the environmental factors such as inappropriate interior and lighting system. Since the HFE is an essential factor for the high fidelity performance of operators in the MCR, the adequate MCR environment design with HFE rules and guidelines is as much important to enhance the operability and reliability of the MCRs. Therefore, there has been a strong need to design a pleasant environment for the MCR to improve human performance of the operators.

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Prediction of velocity and attitude of a yacht sailing upwind by computational fluid dynamics

  • Lee, Heebum;Park, Mi Yeon;Park, Sunho;Rhee, Shin Hyung
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.8 no.1
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    • pp.1-12
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    • 2016
  • One of the most important factors in sailing yacht design is accurate velocity prediction. Velocity prediction programs (VPP's) are widely used to predict velocity of sailing yachts. VPP's, which are primarily based on experimental data and experience of long years, however suffer limitations when applied in realistic conditions. Thus, in the present study, a high fidelity velocity prediction method using computational fluid dynamics (CFD) was proposed. Using the developed method, velocity and attitude of a 30 feet sloop yacht, which was developed by Korea Research Institute of Ship and Ocean (KRISO) and termed KORDY30, were predicted in upwind sailing condition.

Rotorcraft Waypoint Guidance Design Using SDRE Controller

  • Yang, Chang-Deok;Kim, Chang-Joo;Yang, Soo-Seok
    • International Journal of Aeronautical and Space Sciences
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    • v.10 no.2
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    • pp.12-22
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    • 2009
  • This paper deals with the State-Dependent Riccati Equation (SDRE) Technique for the design of rotorcraft waypoint guidance. To generate the flight trajectory through multiple waypoints, we use the trigonometric spline. The controller design and its validation is based upon a level 2 simulation rotorcraft model and the designed SDRE controller is applied to the trajectory tracking problems. To verify the designed guidance law, the simulation environment of high fidelity rotorcraft model is developed using three independent PCs. This paper focuses on the validation of rotorcraft waypoint guidance law which is designed by using SDRE Controller.

Design and Development of an Advanced Real-Time Satellite Simulator

  • Kang, Ja-Young;Kim, Jae-Moung;Chung, Seon-Jong
    • ETRI Journal
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    • v.17 no.3
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    • pp.1-16
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    • 1995
  • An advanced real-time satellite simulator (ARTSS) has been developed to support the ground operations activities of the ETRI satellite control system, such as testing of the system facilities, validation of flight control procedures, verification of satellite commands as well as training of the ground operators. The design of ARTSS is based on the top-down approach and makes use of a modular programming to ensure flexibility in modification and expansion of the system. Graphics-based monitoring and control facilities enhance the satellite simulation environment. The software spacecraft model in ARTSS simulates the characteristics of a geostationary communication satellite using a momentum bias three-axis stabilization control technique. The system can be also interfaced with a hardware payload subsystem such as Ku-band communication transponder to enhance the simulator capability. Therefore, ARTSS is a high fidelity satellite simulation tool that can be used on low-cost desk top computers. In this paper, we describe the design features, the simulation models and the real-time operating functions of the simulator.

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Numerical Analysis of Direct Detonation Initiation Processes in a $H_2-O_2$-Ar Mixture for Pulse Detonation Engine Applications (PDE 응용을 위한 $H_2-O_2$-Ar 혼합물에서의 직접 기폭 과정에 대한 수치 해석)

  • Kyoung Su Im;Chang Kee Kim;Jun Sik Hwang
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2003.10a
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    • pp.204-207
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    • 2003
  • The present paper reports high-fidelity simulation of direct initiation processes of cylindrical detonation waves by concentrated energy deposition. The goal is to understand the underpinning mechanisms in failed or successful detonation initiation processes. We employed the Space-Time CESE method to solve the reacting flow equations, including realistic finite-rate chemistry model of the nine species and twenty-four reactions for H$_2$-O$_2$-Ar mixtures. Detailed results of sub-critical, critical. and supercritical initiation process are reported.

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Color Quality Evaluation of High Color Rendering White LEDs According to Phosphor Types and Composition Ratio (형광체 종류와 조성비에 따른 고연색 백색 LED의 색품질 평가)

  • Jeong, Hee Suk;Ryeom, Jeongduk
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.30 no.7
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    • pp.463-468
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    • 2017
  • Eight types of LED packages were manufactured according to the type and composition ratio of phosphors by using commercially available white LED phosphors. CRI (Ra), a conventional color quality evaluation method was evaluated by using manufactured white LED; the Rf, Rg, color vector graphic, and color distortion graphic were evaluated with a new method, IES TM-30-15. The results of the evaluation confirmed that the new method compensated for the disadvantages of CRI, which was found to be inadequate when the color was saturated. The added evaluation index identified the chroma variation and color change. Furthermore, the study showed that the changes of Rf and Rg are small when controlling phosphors based on CRI, questioningthe necessity of identifyingchroma variation and color change.

A Study on Flight Data Analysis & Animation System Development

  • Kim, Jae-Hyung;Shin, Sung-Sik
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.56.6-56
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    • 2001
  • The FDAS(Flight Data Analysis & Animation System) is a comprehensive analysis system designed for the improvement of flight safety. FDAS provides decoding, analysis and animation tools that can be used for investigation of data origination primarily from Flight Data Recoders(FDRs), Quick Access Recoders(QARs), Using FOQA(Flight Operation Quality Assurance) Data Analysis, an analyst can perform a variety of functions including data smoothing, interpolation, differentiation, integration, calculator function, flight path generation, performance routines, as well as user-programmed functions. Utilizing data captured and processed by our FDAS software module, FDAS provides high-fidelity 3-D aircraft views and instruments views. Multiple windows enable you to view the situation from a variety of perspectives, including out-of-window, chase plane ...

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Development of a Real-time Vehicle Driving Simulator

  • Kim, Hyun-Ju;Park, Min-Kyu;Lee, Min-Cheoul;You, Wan-Suk
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.51.2-51
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    • 2001
  • A vehicle driving simulator is a virtual reality device which makes a human being feel as if the one drives a vehicle actually. The driving simulator is effectively used for studying interaction of a driver-vehicle and developing the vehicle system of new concepts. The driving simulator consists of a motion platform, a motion controller, a visual and audio system, a vehicle dynamic analysis system, a vehicle operation system and etc. The vehicle dynamic analysis system supervises overall operation of the simulator and also simulates dynamic motion of a multi-body vehicle model in real-time. In this paper, the main procedures to develop the driving simulator are classified by 4 parts. First, a vehicle motion platform and a motion controller, which generates realistic motion using a six degree of freedom Stewart platform driven hydraulically. Secondly, a visual system generates high fidelity visual scenes which are displayed on a screen ...

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Simulation Analysis of the Neural Network Based Missile Adaptive Control with Respect to the Model Uncertainty (신경회로망 기반 미사일 적응제어기의 모델 불확실 상황에 대한 시뮬레이션 연구)

  • Sung, Jae-Min;Kim, Byoung-Soo
    • Journal of Institute of Control, Robotics and Systems
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    • v.16 no.4
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    • pp.329-334
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    • 2010
  • This paper presents the design of a neural network based adaptive control for missile. Acceleration of missile by tail fin control cannot be controllable by DMI (Dynamic Model Inversion) directly because it is non-minimum phase system. To avoid the non-minimum phase system, dynamic model inversion is applied with output-redefinition method. In order to evaluate performance of the suggested controllers we selected the three cases such as control surface fail, control surface loss and wing loss for model uncertainty. The corresponding aerodynamic databases to the failure cases were calculated by using the Missile DATACOM. Using a high fidelity 6DOF simulation program of the missile the performance was evaluates.