• Title/Summary/Keyword: design conditions

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Study on the Outdoor Conditions for Air Conditioning Design in Korea (한국의 공기조화설계용 외기조건)

  • 김효경
    • The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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    • v.1 no.1
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    • pp.3-11
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    • 1972
  • The outdoor design conditions for the locality are the basic problem in the design of air conditioning system. The ideal solution to the basic problem is to design a building that has a capacity at maximum output just equal to the load which develops the most severe conditions for the locality occur, but in most cases, economics interferes the attainment of the ideal. Studies of weather records show that the most severe conditions do not repeat themselves every year. The weather conditions of principal cities such as Seoul, Inchon, Suwon, Taegu, Chonju, Ulsan, Kwangju, Pusan and Mokpo in Korea have been analyzed to determine the probability of occurrence of certain temperatures according to recent 10 years $(1960\∼1969)$ weather records. The outdoor conditions for winter air conditioning design are shown on Table 2. The outdoor conditions for summer air condioning design are shown on Table 7. Heating degree days are shown on Table 10 and 11.

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Special cases in fatigue analysis of wind turbines

  • Gunes, Onur;Altunsu, Elif;Sari, Ali
    • Wind and Structures
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    • v.32 no.5
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    • pp.501-508
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    • 2021
  • The turbine industry demands a reliable design with affordable cost. As technological advances begin to support turbines of huge sizes, and the increasing importance of wind turbines from day to day make design safety conditions more important. Wind turbines are exposed to environmental conditions that can affect their installation, durability, and operation. International Electrotechnical Commission (IEC) 61400-1 design load cases consist of analyses involving wind turbine operating conditions. This design load cases (DLC) is important for determining fatigue loads (i.e., forces and moments) that occur as a result of expected conditions throughout the life of the machine. With the help of FAST (Fatigue, Aerodynamics, Structures, and Turbulence), an open source software, the NREL 5MW land base wind turbine model was used. IEC 61400-1 wind turbine design standard procedures assessed turbine behavior and fatigue damage to the tower base of dynamic loads in different design conditions. Real characteristic wind speed distribution and multi-directional effect specific to the site were taken into consideration. The effect of these conditions on the economic service life of the turbine has been studied.

An Analysis on the Problems of General Conditions for Domestic Design-Build Construction Projects (국내 설계${\cdot}$시공일괄발주방식을 위한 공사계약 일반조건의 문제점 분석)

  • Seo Young-Min;Park Chan-Sik
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • autumn
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    • pp.303-306
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    • 2003
  • Although design-build construction projects have recently increased. general conditions of construction contract are not reflecting the characteristic of design-build construction projects neither performing its fundamental roles as implying many claim elements. So. this study aims to propose the basis for improving the general conditions of the domestic design-build construction projects. This study reviews literatures associated with design-build construction contract and analyses domestic general conditions into foreign standard forms of general conditions. Additionally, it is examined the problems of design-build construction contracts and performed questionnaire survey to the practitioner in the construction contract field. In doing so, this study suggests the direction for improving general conditions of domestic design-build construction projects.

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The Effects of Compressor Design Conditions on the Off-Design Performance of a Gas Turbine Engine (압축기 설계조건이 가스터빈 엔진의 탈설계점 성능에 미치는 영향)

  • 강동진;정평석;안상규
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.18 no.9
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    • pp.2413-2422
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    • 1994
  • The effects of compressor design conditions on the off-design performance of a single-shaft gas turbine engine have been studied. Three different geometric design conditions are considered and three different values for the specific mass flow rate at the inlet to the compressor are assumed. For each of nine compressor design, the off-design performance of the gas turbine engine is predicted using the method previously proposed by present authors. Results show that the predicted off-design performances are quite different from each other even though they have the same performance at design point: it means that compressor design conditions should be determined in consideration of the off-design performance of the engine. The specific mass flow rate at the inlet to the compressor is also shown that it might be optimized with respect to the net power of the engine.

A Study on the Design Theory of a Mechanical System : Using a Washing Machine Transmission as a Model (세탁기용 트랜스미션을 모델로 한 기계 시스템 설계이론에 관한 연구)

  • Cheon, Gil-Jeong;Kim, Wan-Du;Han, Dong-Cheol
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.20 no.2
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    • pp.431-439
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    • 1996
  • New design principles nad necessary conditions for a mechanical system have been suggested to be kept in the design process using a washing machine transmission as a model. The necessary conditions are funcitnal requirement condition and spatial arrangement condition. The design principles to satisfy the necessary conditions are the principle of sequence and the principle of expansion. Decision sequence for state variables and design varibles of various mechanicla elements have been formulated. New automatic design program for washing machine transmission has been developed observing the necessary conditions and design principles investigated in this study. It was verified to be very effective to follow the design conditions, principles nad formulated decision sequence in mechanical system design process.

An Analysis of the Outdoor Design Conditions for Heating and Air Conditioning in Korea (한국의 냉난방 설계용 외기조건 분석)

  • Bang, Gyu-Won
    • The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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    • v.14 no.4
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    • pp.322-356
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    • 1985
  • The outdoor design conditions for summer and winter are basic data required for determining the heating and cooling loads and HVAC equipment capacity. The latest study reported was based on the 1960's weather data, which is widely used by HVAC design engineers in Korea. The purpose of this paper is to update the outdoor design conditions for HVAC loads and equipments based on the weather data for the 1970's. The weather conditions of 24 sites, namely Sokcho, Chuncheon, Gangreung, Seoul, Inchon, Ulreungdo, Suweon, Seosan, Cheongju, Daejeon, Chupungryeong, Pohang, Gunsan, Daegu, Jeonju, Ulsan, Kwangju, Busan, Chungmu, Mokpo, Yeosu, Jeju, Seogwipo, and Jinju have been analyzed to calculate the outdoor design conditions. This analys is performed on the basis of TAC $1\%,\;TAC\;2.5\%,\;and\;TAC\;5\%$.

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High-Tc superconducting magnet properites with design conditions (설계조건에 따른 고온 초전도 마그넷의 특성변화)

  • Kim, Min-Ki;Ko, Yo;Han, Byoung-Sung
    • Electrical & Electronic Materials
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    • v.8 no.4
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    • pp.451-457
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    • 1995
  • Most important study on development of high-Tc superconducting magnet is magnetic properties with design conditions To study optimal design condition of high-Tc superconducting magnet, small size solenoid magnet was designed and simulated. Design conditions are radius of bobbin, radius of magnet, length of magnet, critical cur-rent and notch size. We know that intensity of magnetic fields was controled by critical current and uniformity of magnetic fields was controled by notch size. The optimal design conditions to get the high intensity and uniformity of magnetic field in this experiments were radius of bobbin=3[cm], radius of magnetic=12[cm], length of Z=10[cm], notch size=6[cm] and critical current=12[A].

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A Study on Design Factors of Air Diffuser Systems in Reservoirs: Application of Field Conditions to the CFD Simulation (산기식 물순환장치 설계인자 연구: 현장 댐 조건을 고려한 CFD 해석 중심)

  • Shin, Sang-Min;Lee, Seung-Jae;Lee, Sang-Eun;Park, Hee-Kyung;Yum, Kyung-Taek
    • Journal of Korean Society of Water and Wastewater
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    • v.25 no.2
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    • pp.161-169
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    • 2011
  • This study aims at examining the design factors of the air diffuser system in a particular view of field conditions, and thus improving the procedures currently applied to design the system. First, the CFD model is built for an air diffuser system suitable for field conditions of real reservoirs. Then, the design factors, including destratification number, destratification radius and efficiency of the air diffuser system, are analyzed after a series of simulations over various field conditions. The result shows successful correlations of design factors with DN at the condition, and they lead to estimate of the destratification radius and efficiency of air diffuser system based on DN. It is finally concluded that the design factors are improved such that the air diffuser system is suitable for the field conditions of dam reservoirs.

Multi-Point Aerodynamic Design Optimization of DLR F-6 Wing-Body-Nacelle-Pylon Configuration

  • Saitoh, Takashi;Kim, Hyoungjin;Takenaka, Keizo;Nakahashi, Kazuhiro
    • International Journal of Aeronautical and Space Sciences
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    • v.18 no.3
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    • pp.403-413
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    • 2017
  • Dual-point aerodynamic design optimization is conducted for DLR-F6 wing-body-nacelle-pylon configuration adopting an efficient surface mesh movement method for complex junction geometries. A three-dimensional unstructured Euler solver and its discrete adjoint code are utilized for flow and sensitivity analysis, respectively. Considered design conditions are a low-lift condition and a cruise condition in a transonic regime. Design objective is to minimize drag and reduce shock strength at both flow conditions. Shape deformation is made by variation of the section shapes of inboard wing and pylon, nacelle vertical location and nacelle pitch angle. Hicks-Henne shape functions are employed for deformation of the section shapes of wing and pylon. By the design optimization, drag coefficients were remarkably reduced at both design conditions retaining specified lift coefficient and satisfying other constraints. Two-point design results show mixed features of the one-point design results at low-lift condition and cruise conditions.

A Design of Vehicle Active Suspension Controller with Variable Control Objects Determined by Driving Conditions (주행 상황에 따라 다양한 제어목적을 가지는 차량 능동 현가장치 제어기 설계)

  • Cheon, Jong-Min;Kim, Seog-Joo;Park, Jong-Moon;Kwon, Soon-Man
    • Proceedings of the KIEE Conference
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    • 2005.10b
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    • pp.346-348
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    • 2005
  • In this paper, we designed a vehicle active suspension controller. Vehicle suspensions have various design objects with tradeoff among them and these objects cannot be satisfied under all driving conditions. We need to design a controller adapted to variable driving conditions changing the objects of vehicle suspensions. To design such a controller, we must be able to detect the current driving conditions and focus on the road frequencies giving us useful and important information about driving conditions. Detecting the road frequencies, we use the Fourier Transform. A unexpected driving change like a speed bump was also included to items the new designed controller must consider.

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