• Title/Summary/Keyword: Off-Design Conditions

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Empirical Analysis of Factors which Generate Voluntary Participation in Selling Centers

  • SCHWARZKOPF, Rico
    • Journal of Distribution Science
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    • v.18 no.5
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    • pp.83-88
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    • 2020
  • Purpose of the research: In response to the increasing number of selling centers, this paper examines factors that influence the voluntary participation in selling centers. The goal of this study is to enable organizations to meet changing market conditions, which require interdisciplinary collaboration during sales projects. This paper also discusses potential problems which may occure during the implementation of these factors in practice. Research design and methodology: The research method consists of a qualitative cross-sectional study with N=12 interviewees. All interviewees are current or former selling center participants. During the interview sessions, semi-structured face-to-face interviews were used, which were evaluated using a qualitative content analysis. In addition, a frequency analysis was applied to evaluate the number of mentions per factor. Research results: In total, five factors were raised in order to improve the framework conditions of voluntary participation. These factors are performance incentives, transparency, availability of resources, goal orientation, as well as collegiality and affiliation. Major conclusions: The identified factors are also under discussion in the existing literature. Knowing about factors that generate voluntary participation in selling centers pays off particularly in improving the probability of completion of sales projects in which buying centers and selling centers are working together.

Installed Performance Analysis of a Turboshaft Engine Considering Inlet and Exhaust Losses Estimated by Cfd Technique (CFD 기법에 의해 예측된 흡입구 및 배기구 손실을 고려한 터보축 엔진의 장착성능에 관한연구)

  • Kong Chang-Duk;Owino George Omollo
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2006.11a
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    • pp.106-109
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    • 2006
  • The purpose of this study is to analyze the installed performance of the PW206C turbo shaft engine used in the development of the smart UAV(Unmanned Ariel Vehicle) by KARI(Korean Aerospace Research Institute). It mainly aims to investigate performance behavior at installed conditions using both inlet and exhaust losses generated by CFD analysis of the ducts. The ways employed to be able to analyze the performance extensively were mainly rallied out by performing design point analysis of the engine where the performance simulation results from the commercial program 'GASTURB 9' used for simulation were used as inlet boundary condition for the ducts in CFD program The use of CFD tool involve modeling of the ducts to conform with the stipulated shape and sizes as defined by KARI with a grid density that allows reasonable flow characteristics applicable to aircraft components. Respective values of Shaft horse power obtained by varying flight Mach number, Gas generator RPM and Altitude considering several losses inclusive of those estimated by use of CFD tool were then plotted at three conditions with the ECS-OFF, ECS-MAX and at un-installed condition. Reasonable results were obtained as a result of using computational fluid dynamics that can hence be justified as an alternative tool for use in future flow analysis of engine and components.

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The Effects of Engine's Misfiring Condition on the Dynamic Behaviour of Resilient Mounting Systems (엔진의 착화실패가 탄성지지계의 동적거동에 미치는 영향)

  • 장민오;손석훈;김의간;김의간
    • Journal of KSNVE
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    • v.6 no.4
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    • pp.503-511
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    • 1996
  • There is a tendency of using the resilient mounting system to control the structure born noise transimitted from a engine of which weight is comparatively light and of which speed is comparatively high. According to recent reports, the resilient mounting system is applied to control the vibration of a engine running up to 300 - 400 R.P.M.. Furthermore, the resilient system is also used to the ships such as marine exploring ships, fishing boats, and military vessels. It is not desirous to apply the results for the resilient mounting systems of automobile engines to the controls of the vibrations of marine engines. Marine engines are worked under the idle speed in port and are operated up to the maximum contineous revolution at sea(running up condition). And marine engines are usually worked in inevitable conditions such as a misfire and a cut-off cylinder operating condition. Concerning the above running conditions, a resilient mounting system should be designed in the case of marine engines. In this paper, we studied the effect of engine's misfire on the resilient mounting systems. And the influences of design parameters, such as dynamic characteristics and fitting angles of resilient rubber mountings, were also investigated respectively on the single and double resilient mounting systems.

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Fire Risk Assessment for Subway Station According to Supply and Exhaust Conditions (지하철 승강장 급배기 조건에 따른 화재 위험성 평가)

  • Kim, Ha-Young;Rie, Dong-Ho;Kim, Jung-Yup
    • Fire Science and Engineering
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    • v.22 no.5
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    • pp.29-34
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    • 2008
  • In this research, to establish the emission for the people who are clearing out, through the numerical analysis using the CFD model, the dangerousness has been investigated in the various emission conditions in a station platform. As a result of research, it is found out that the temperature variation falls between 65.37% and 74.97% to compare without installation of platform screen doors. In the addition, with the supply mode or push-pull mode, the warm current is generated in the platform so the temperature and the layer of smoke are stirred up and felled off. It will make the dangerousness when the people escape. Therefore, when the capacity of emission and the space of platform is set up, the design regards the properties of the fire emission.

Development of WT-FC Hybrid System for Off-Grid (오프그리드용 풍력-연료전지 하이브리드 시스템 개발)

  • Choi, Jong-Pil;Kim, Kwang-Soo;Park, Nae-Chun;Kim, Sang-Hun;Kim, Byeong-Hee;Yu, Neung-Su
    • New & Renewable Energy
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    • v.3 no.2 s.10
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    • pp.60-67
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    • 2007
  • This paper describes the design and integration of the wind-fuel cell hybrid system. The hybrid system components included a wind turbine, an electrolyzer (for generation of H2), a PEMFC (Proton Exchange Membrane Fuel Cell), hydrogen storage tank and BOP (Balance of Plant) system. The energy input is entirely provided by a wind turbine. A DC-DC converter controls the power input to the electrolyzer, which produces hydrogen and oxygen form water. The hydrogen used the fuel for the PEMFC. Hydrogen may be produced and stored in high pressure tank by hydrogen gas booster system. Wind conditions are changing with time of day, season and year. So, wind power is a variable energy source. The main purpose with these WT-FC hybrid system is to store hydrogen by electrolysis of water when wind conditions are good and release the stored hydrog en to supply the fuelcell when wind is low.

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Modelling of the fire impact on CONSTOR RBMK-1500 cask thermal behavior in the open interim storage site

  • Robertas Poskas;Kestutis Rackaitis;Povilas Poskas;Hussam Jouhara
    • Nuclear Engineering and Technology
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    • v.55 no.7
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    • pp.2604-2612
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    • 2023
  • Spent nuclear fuel and long-lived radioactive waste must be carefully handled before disposing them off to a geological repository. After the pre-storage period in water pools, spent nuclear fuel is stored in casks, which are widely used for interim storage. Interim storage in casks is very important part in the whole cycle of nuclear energy generation. This paper presents the results of the numerical study that was performed to evaluate the thermal behavior of a metal-concrete CONSTOR RBMK-1500 cask loaded with spent nuclear fuel and placed in an open type interim storage facility which is under fire conditions (steady-state, fire, post-fire). The modelling was performed using the ANSYS Fluent code. Also, a local sensitivity analysis of thermal parameters on temperature variation was performed. The analysis demonstrated that the maximum increase in the fuel load temperatures is about 10 ℃ and 8 ℃ for 30 min 800 ℃ and 60 min 600 ℃ fires respectively. Therefore, during the fire and the post-fire periods, the fuel load temperatures did not exceed the 300 ℃ limiting temperature set for an RBMK SNF cladding for long-term storage. This ensures that fire accident does not cause overheating of fuel rods in a cask.

Performance Test of a R134a Centrifugal Water Chiller

  • Jeong, Jin-Hee;Yoon, Pil-Hyun;Kim, Ghil-Yeung;Lee, Hyeon-Koo
    • International Journal of Air-Conditioning and Refrigeration
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    • v.10 no.2
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    • pp.97-105
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    • 2002
  • A centrifugal water chiller using alternative refrigerant R134a has been developed. The prototype was designed to have refrigerating capacity of 300RT. Its compressor employs a single high-speed impeller, airfoil diffuser and collector. Newly developed, enhanced tubes were installed in the evaporator and the condenser to reduce the required head for the compressor. Off-design characteristics at various conditions, performance test of the compressor and analysis of the refrigeration cycle were performed. So the probability of use in part load condition was checked and the direction for revision was suggested.

Development of Tractor Three-point Hitch Control System using Proportional Valve (비례밸브를 이용한 트랙터 3점 히치 제어 시스템 개발)

  • Lee, Sang-Sik;Park, Won-Yeop
    • Journal of Biosystems Engineering
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    • v.36 no.2
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    • pp.89-95
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    • 2011
  • Tractor implements are mainly utilized for the tillage operation. The proposed hydraulic system control was implemented to experimental apparatus. An implement control system for tractor using proportional valve was fabricated to improve the working efficiency. Hydraulic circuit included the proportional solenoid valve and on/off solenoid valve and so on. This paper shows results of a specification and design of an implement control system for tractor using proportional valve for automation. It was conducted to evaluate response characteristics of the designed implement control system under experimental conditions of various input flow rates. The results of experiments showd that the response characteristics was sufficient to be used as the implement control system.

Etching Characteristics of Au Film using Capacitively Coupled CF4/Ar Plasma

  • Kim, Gwang-Beom;Hong, Sang-Jeen
    • Journal of the Speleological Society of Korea
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    • no.82
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    • pp.1-4
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    • 2007
  • In this paper, the etching of Au films using photoresist masks on Si substrates was investigated using a capacitively coupled plasma etch reactor. The advantages of plasma etch techniques over current methods for Au metalization include the ability to simplify the metalization process flow with respect to resist lift-off schemes, and the ability to cleanly remove etched material without sidewall redeposition, as is seen in ion milling. The etch properties were measured for different gas mixing ratios of CF4/Ar, and chamber pressures while the other conditions were fixed. According to statistical design of experiment (DOE), etching process of Au films was characterized and also 20 samples were fabricated followed by measuring etch rate, selectivity and etch profile. There is a chemical reaction between CF4 and Au. Au- F is hard to remove from the surface because of its high melting point. The etching products can be sputtered by Ar ion bombardment.

Swelling Pressures of a Potential Buffer Material for High-Level Waste Repository

  • Lee, Jae-Owan;Cho, Won-Jin;Chun, Kwan-Sik
    • Nuclear Engineering and Technology
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    • v.31 no.2
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    • pp.139-150
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    • 1999
  • The swelling pressure of a potential buffer material was measured and the effect of dry density, bentonite content and initial water content on the swelling pressure was investigated to provide the information for the selection of buffer material in a high-level waste repository. Swelling tests were carried out according to Box-Behnken's experimental design. Measured swelling pressures were in the wide range of 0.7 Kg/$\textrm{cm}^2$ to 190.2 Kg/$\textrm{cm}^2$ under given experimental conditions. Based upon the experimental data, a 3-factor polynomial swelling model was suggested to analyze the effect of dry density, bentonite content and initial water content on the swelling pressure The swelling pressure increased with an increase in the dry density and bentonite content, while it decreased with increasing the initial water content and, beyond about 12 wt.% of the initial water content, levelled off to nearly constant value.

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