• 제목/요약/키워드: Inlet Performance

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입구형상에 따른 소형 사이클론의 성능 실험 (Experiment of small cyclone performance depending on the inlet type)

  • 김민하;허광수;설승윤
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 춘계학술대회
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    • pp.1969-1974
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    • 2004
  • The performance of small cyclone is analysed by an experiment for the purpose of developing a bag-less vacuum cleaner. For the high collection efficiency and low pressure loss cyclone, the effect of cyclone inlet feature must be well understood. Four types of the helical inlet are considered to compare with the normal tangential inlet, and also various inlet velocities are used to each inlet type. Based on the reference dimension, each type of inlet shows the changes of the grade efficiency and pressure loss which determine the cyclone quality. The results show that the helical inlet has the smaller cut-size but bigger pressure loss than the tangential inlet. And the degree of opening area influences factors of cyclone performance. As the inlet velocity is increased, the cut-size becomes smaller and the pressure loss becomes bigger of each cyclone. Further studies are required to understand the optimized helical inlet of cyclone.

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터빈입구온도 보정기법을 적용한 가스터빈 성능진단 프로그램 개발 (Development of a Performance Diagnosis Program for Gas Turbines Using Turbine Inlet Temperature Correction)

  • 이재홍;강도원;김동섭
    • 한국유체기계학회 논문집
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    • 제20권2호
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    • pp.32-40
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    • 2017
  • In this study, an in-house program to analyze the performance degradation for gas turbines is developed using MATLAB and is validated using commercial software. This program consists of design and off-design calculations. The results of design calculation is used for reference values of off-design calculation. The off-design calculation is composed of measured and expected performance analyses, and turbine inlet temperature correction. In general, performance degradation is analyzed by comparing the results of measured and expected performance analysis. However, if gas turbine performance degrades, turbine inlet temperature might increase due to the general control logic to comply with the power demand. Therefore, it is required to consider the deviation of turbine inlet temperature from the normal value in the performance diagnosis to analyze the performance degradation exactly. In this study, a special effort is given to the correction of turbine inlet temperature. The accuracy of the developed program is confirmed by comparison with commercial software, and its capability of performance diagnosis using the turbine inlet temperature correction is demonstrated.

상용 CFD코드를 이용한 공조기 입구 형상 설계 (Inlet Shape Design of Air Handling Unit Using Commercial CFD Code)

  • 최영석;주종일;이용갑;주원구
    • 한국유체기계학회 논문집
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    • 제5권3호
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    • pp.54-59
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    • 2002
  • A commercial CFD code is used to compute the 3-D viscous flow field within the inlet flow concentrator of the newly developed AHU (Air Handling Unit). To improve the performance of the AHU, the inlet air needs to be gradually accelerated to the fan's annular velocity without causing turbulence or flow separation. Three major geometric parameters were selected to specify the inlet shape of the AHU. The performance of the AHU could be measured by the inlet and outlet flow uniformity and the total pressure loss through the inlet flow concentrator. Several numerical calculations were carried out to determine the influence of the geometric parameters on the performance of the AHU. The best geometric values were decided to have efficient inlet shape with analyzing CFD calculation results.

상용 CFD코드를 이용한 공조기 입구형상의 설계 (Inlet Shape Design of Air Handling Unit Using Commercial CFD Code)

  • 최영석;주종일;주원구
    • 유체기계공업학회:학술대회논문집
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    • 유체기계공업학회 2001년도 유체기계 연구개발 발표회 논문집
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    • pp.448-453
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    • 2001
  • A commercial CFD code is used to compute the 3-D viscous flow field within the inlet flow concentrator of the newly developed AHU(Air Handling Unit). To improve the performance of the AHU, the inlet air needs to be gradually accelerated to the fan's annular velocity without causing turbulence or flow separation. Three major geometric parameters were selected to specify the inlet shape of the AHU. Several numerical calculations are carried out to determine the influence of the geometric parameters on the performance of the AHU. The performance of the AHU could be measured by the inlet and outlet flow uniformity and the total pressure loss through the inlet flow concentrator. The optimized nondimensionalized velocity profile through the inlet flow concentrator were used for the design of the AHU with the various volume flow rates.

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패드의 선단압력을 고려한 부채꼴 모양의 피봇식 추력베어링의 성능해석 (An analysis of the performance of sector shaped, pivoted pad thrust bearings in consideraation of the inlet pressure)

  • 김종수;김경웅
    • 대한기계학회논문집
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    • 제12권5호
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    • pp.1063-1070
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    • 1988
  • 본 연구에서는 부채꼴형 유한폭 패드베어링에서의 선단압력을 구하기 위하여 3차원 유동모델을 제시하였으며, 이 유동모델을 기초로 하여 구해진 선단압력을 패드 선단에서의 압력경계조건으로 사용하여 유막내의 압력을 구하고 베어링의 하중지지능 력, 마찰토오크 및 윤활유량등을 계산함으로써 베어링의 성능을 해석하였다. 그 결 과 선단 압력이 크게 발생하는 운전조건일수록 선단압력을 무시한 종래의 베어링 성능 해석결과와는 상당한 차이가 있었으며, 특히 관성계수가 큰 운전조건에서 사용되는 피 봇식 추력베어링에서는 선단압력의 영향으로 인하여 하중지지능력을 최대로하는 피봇 점의 위치가 패드 선단부쪽으로 크게 이동되었다.

양흡입 원심블로어 성능향상을 위한 입구 유동 최적화 연구 (Evaluation of Inflow Uniformity on the Performance of Double-Inlet Centrifugal Blower Using Optimal Design Method)

  • 이종성;장춘만;전현준
    • 한국수소및신에너지학회논문집
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    • 제24권4호
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    • pp.326-333
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    • 2013
  • This paper presents the performance enhancement of a double-inlet centrifugal blower by the shape optimization of an inlet duct. Two design variables, a length of anti circulation vane and an angles of inlet guide, are introduced to improve the inlet flow uniformity leading to the blower performance. Three-dimensional Navier-Stokes equations are used to analyze the blower performance and the internal flow of the blower. From the shape optimization of the inlet duct of the double-inlet centrifugal blower, the optimal positions of each design variable are determined. Throughout the analysis of sensitivity, it is found that the angle of the inlet guide is more effective than the length of the anti-circulation vane to increase flow uniformity at the outlet of the duct. Efficiency and pressure for the optimal inlet duct shape are successfully increased up to 3.55% and 3.2% compared to those of reference blower at the design flow condition, respectively. Detailed flow field inside the blower is also analyzed and compared.

사각형 단순 확장소음기의 성능향상을 위한 입$\cdot$출구 위치의 최적설계 (Optimum Design for Inlet and Outlet Locations of Rectangular Expansion Chamber for Improving Acoustic Performance)

  • 김봉준;정의봉;황상문
    • 소음진동
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    • 제9권4호
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    • pp.738-746
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    • 1999
  • The performance of muffler can be improved for a frequency range of interest by moving inlet and outlet locations. And optimal location of inlet and outlet can be determined to improve the acoustic performance. The optimum design using FEM, however, may take a very long time and be very hard to take inlet and outlet locations as design variables. In this paper, the acoustic performance of reactive type single expansion chamber muffler is predicted using higher order mode theory. The sensitivity analysis of transmission loss with respect to the location of inlet and outlet is suggested. And the acoustic power transmission coefficient for a frequency of interest is used as cost function. Optimum location of inlet and outlet is determined to minimize cost function by using SUMT algorithm.

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가스터빈 엔진의 입구 유동 왜속 시험 (Inlet Distortion Test of Gas Turbine Engine)

  • 이진근;이경재;고성희;곽재수
    • 항공우주시스템공학회지
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    • 제1권1호
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    • pp.53-59
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    • 2007
  • Inlet distortion test was performed at Korea Aerospace Research Institute in order to evaluate the degradation of engine performance under the distorted inlet condition. In this paper, only the inlet pressure distortion was taken into consideration. During the development process of the inlet distortion test technique, variable distortion screen was designed and evaluated under various test conditions to establish the experimental database of distortion for engine test. The result of inlet distortion test for engine shows that the operating point was changed toward the worse direction and the degradation of engine performance by inlet distortion was verified.

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선단압력을 고려한 공기윤활 틸팅패드베어링의 정특성 (The Static Performances of Air-Lubricated Tilting Pad Bearings With Inlet Pressure)

  • 김성국;김경웅
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 1998년도 제27회 춘계학술대회
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    • pp.235-240
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    • 1998
  • The inlet pressure build-up at the leading edge of bearings and its effects on the static performances are investigated theoretically. The performance analyses of air-lubricated tilting pad bearings are carried out considering the inlet pressure which is obtained by means of momentum conservation method. The results show that inlet pressure is above atmosphere pressure in front of leading edge of tilting pad bearing and there is a significant influence of the inlet pressure on the performance of bearings.

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PAC용 양흡입 시로코홴의 공력성능에 관한 실험적 연구 (Experimental Study on the Aerodynamic Performance of Double Inlet Sirocco Fan for a Package Air Conditioner)

  • 김장권;오석형
    • 동력기계공학회지
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    • 제17권1호
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    • pp.58-63
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    • 2013
  • The aerodynamic performance of double inlet sirocco fan is strongly dependent upon the design factors of impeller and scroll. In this paper, the change of scroll size was adopted to investigate the aerodynamic performances of double inlet sirocco fan and indoor PAC. Especially, a scroll expansion angle and a cut-off clearance ratio were considered to change the scroll size. In addition, the installation depth between double inlet sirocco fan and indoor PAC was considered. As a result, the total pressure efficiency of double inlet sirocco fan shows about 62%~73% according to the change of scroll expansion angles. Moreover, the flowrate performance of indoor PAC is the best at the condition of a scroll expansion angle of 8°, an installation depth of 15 mm and a cut-off clearance ratio of 8%.