• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.10a
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• pp.62-67
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• 2004

This paper investigates the off-design performance of methane-fueled air turbo ramjet(ATR) engine in subsonic flight speed range. The ATR engine was modeled and simulated numerically. Each component was modeled to enable their off-design calculation. Compressor operating point was determined by flow matching with nozzle, and turbine by work matching. The ATR engine exhibited quite different off-design behavior compared to the conventional gas turbine engine.

• Journal of the Korea Institute of Military Science and Technology
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• v.4 no.2
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• pp.60-69
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• 2001

전달정렬은 MINS와 SINS의 비정렬 요소를 칼만필터로 추정하는 기법으로서 본 논문에서는 속도 및 자세정합 칼만필터 설계 결과를 제시하였다. 그리고 설계된 칼만필터는 항법컴퓨터에 실현되어 성능평가가 실행되었는데 성능평가 방법은 실제 함정에서 시험의 어려운 점을 고려하여 실험실에 설치된 3축 각운동 시뮬레이터를 이용하는 방법을 제시하였다. 이러한 성능평가 결과는 전달정렬 설계과정에서 예측되었던 성능 및 특성과 일치하였다.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.396-401
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• 2006

A "Housing Performance Grade Indication System" that is bound to present the grade in housing designs has been executed since January 2006 in order to build sustainable housing and supply high quality housing. Thus, users are able to select their housing based on certain comparisons in housing performances, and providers can be exactly evaluated using precise standards according to the execution of this system. The objective of this study is to propose a guideline in designs according to the grade of housing as a reasonable decision making tool in order to obtain a high grade in housing performance grades under the execution of the "Housing Performance Grade Indication System". In order to perform this goal, this study examines the performance evaluation item and evaluation guidelines in the "Housing Performance Grade Indication System" and analyzes relative systems and guidelines executed in the present time to investigate certain relativeness for this system. The housing performance evaluation item can be classified four different categories according to the characteristics of evaluation guidelines. Then, the system of a design guideline is configured to propose a reasonable design guideline according to the grade of housing performances. It is evident that the design guideline proposed in this paper will support the reasonable decision making to obtain a high grade in housing performances for the designer and constructor in the process of a housing project.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1999.10a
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• pp.5-5
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• 1999

3단형 과학로켓(KSR-III)의 기본형 및 응용형에 공통으로 사용되는 주엔진은 액체산소를 산화제로, 케로신을 연료로 사용하는 액체추진기관이다. 엔진 기본설계를 통하여 로켓 임무 요구사항에 부합되도록 엔진 각 부분의 기본제원을 설정하였고, 엔진의 형상을 결정하였다. 설계된 엔진의 성능검증 작업은 분사시험용 엔진, 축소형 엔진, 엔지니어링 모델 및 비행시험모델의 설계/제작/시험을 통하여 순차적으로 수행할 계획이다. 본 연구는 3단형 과학로켓 엔진의 기본설계 및 성능검증 계획에 관한 것이다.

• Journal of Aerospace System Engineering
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• v.13 no.1
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• pp.38-46
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• 2019

There is a growing interest in engine diagnostic technology for gas turbine engines. An engine simulation program, precisely simulating the engine performance, is required in order to apply it to the engine diagnosis technology for engine health monitoring. In particular, the simulation program can predict not only design point performance but also off-design point and partial load performance in accurate. So the engine simulation program for the 2-spool separate flow type turbofan engine was developed and the JT9D-7R4G engine of PW(Pratt & Whitney) was analyzed. The steady-sate performance analysis is conducted at both design and off-design points in flight path and the differences between analysis results of takeoff and cruise conditions are compared. The effect of Reynold's correction method was analyzed as a scaling method of the engine component performance. The simulation results was compared with NPSS.

• 어항어장
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• s.89
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• pp.54-60
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• 2010

성능설계법은 ISO(국제표준화기구)를 중심으로 세계에서 공통화가 추진되어 국제규격으로서 인지되기 시작하고 있다. 내진성능을 고려한 설계에서 레벨1 레벨2의 2단계를 고려해 상정 지진동을 설정함과 동시에 각각의 지진동 레벨에 따라 적절히 허용재해정도를 설정하여, 구조물의 내진성을 종합적으로 규정한다.

• Journal of the KSME
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• v.26 no.6
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• pp.467-473
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• 1986

설계기술을 자립적으로 개발하려면 다음과 같은 몇 가지의 문제점과 이에 대한 대책이 있어야 한다. (1)공학적인 기초연구 및 개발에 대한 필요성을 분명하게 인식하고 기초연구 및 개발에 대한 화고한 추진의욕과 자세를 갖도록 한다. (2)기업주도형의 실질적인 산학협동방안을 강구 한다. (3)설계기술의 개발을 유발하고 촉진하는 방안을 강구한다. (4)연구 및 개발의 능력을 가진 기술인력을 확보한다. (5)성능 및 품질에 대한 성능시험설비를 확보하고 성능보증제도를 확립한다.

• The KSFM Journal of Fluid Machinery
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• v.3 no.1 s.6
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• pp.43-50
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• 2000

Upgrade development of a high pressure ratio centrifugal compressor in marine engine turbochargers is presented. A new matched operating point at increased speed of rotation was determined through system cycle analysis using the exisitng test data of turbine performance. Under some severe restrictions for geometric parameters, the state-of-the-art methods of both aerodynamic design and CFD analysis were applied, in which only an impeller, a vaned diffusor and some part of casing wall were modified. Prototype hardware was fabricated and assembled for system performance tests. Excellent performance in pressure ratio and efficiency was obtained over whole speed region. Reduced surge and choke margin was, however, observed at design speed of rotation.

• Journal of Korean Tunnelling and Underground Space Association
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• v.15 no.4
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• pp.415-429
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• 2013

Performance-based design is becoming a key word for structure design in architectural and civil engineering spheres. In this paper, the need of the performance-based design, especially for tunnels, was enhanced by case study on the largely deformed cut-and-cover arch tunnel built by the prescribed design. In addition, this paper introduces effective method of subdivision on tunnel performance to help field engineer's comprehension. Case study dealing with the issue of typical backwards problem in geotechnical engineering was examined. First of all, the outline of the damaged culvert as well as the surrounding embankment is in detail described. The background, together with the cause of damage, is discussed based on the results of site investigation. Secondly, it was attempted to elucidate the deformation mechanism of the embankment by means of numerical analysis, and the countermeasures are proposed. Finally, the stability of the embankment with the countermeasures was evaluated.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.6A
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• pp.561-572
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• 2010

This paper is a study about application of recently proposed Performance Based Mixture Design (PBMD) for design of high strength concrete (HSC) to obtain HSC mix proportion that satisfies required performances. The PBMD method which uses Satisfaction curve based on a Bayesian method is a performance oriented concrete mix proportion design procedure easily applicable to any condition and environment for a possible replacement to the current prescriptive design standards. Based on extensive experimental results obtained for various materials and performance parameters of HSC, the application feasibility of the developed PBMD procedure for HSC has been verified. Also, the proposed PBMD procedure has been used to perform application examples to obtain desired target performances of HSC with optimum concrete mixture proportions using locally available materials, local environmental conditions, and available concrete production technologies. The validity and precision of HSC mix proportion design obtained using the PBMD method is verified with the experimental and ACI presented results to check the feasibility for actual design usage.