• 제목/요약/키워드: 5-hole probe

검색결과 86건 처리시간 0.032초

5공 압력프로브의 측정에 의한 Gun식 가스버너의 스월유동장 고찰 (Investigation of the Swirling Flow Fields of a Gun-Type Gas Burner by the Measurement of a Five-Hole Pressure Probe)

  • 김장권;오석형
    • 동력기계공학회지
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    • 제19권1호
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    • pp.19-23
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    • 2015
  • The swirling flow fields of a gun-type gas burner(GTGB) without a combustion chamber were measured by a straight-type five-hole pressure probe(FHPP) under the cold flow condition. The three kinds of velocity components and the static pressure were calculated by using a non-nulling calibration method covering the velocity reduction performance of the effective flow attack angle of ${\pm}80^{\circ}$. As a result, the velocity and static pressure measured by a FHPP comparatively shows the better performance on the swirling flow of a GTGB than those measured by X-probe.

비파괴 검사를 위한 PZT 탐촉자의 제작 및 특성에 관한 연구 (A Study on Fabrication and Characteristics of PZT Probe for Nondestructive Test)

  • 김철수;정규원;송준태
    • 한국전기전자재료학회논문지
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    • 제11권8호
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    • pp.613-619
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    • 1998
  • Ultrasonic probes of 400kHz, 1MHz were fabricated using PZT-5Z plates. Epoxy was used for backing layer materials onthe plates. Nondestructive Test was carried using these probes. Pulse lobe width of impulse response was reduced 15.4% compare 1MHz with 400kHz and 96.6% compare 3MHz with 400kHz. The attenuation in aluminum was 2.05[dB/m] at 400kHz, 4/91[dB/m] at 1MHz, 7.35[dB/m] at 3HMz. Hole detection error of the first hole was 22.4% at 1HMz, 9.% at 3HMz, The second hole 11.6% at 1HMz, 4.7% at 3HMz. In the result of experiment of the hole detection error and resolution, 3HMz probe was the best among them.

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복잡한 유동장에서도 신뢰성 있는 5공프로브 널링기법의 개발 (Development of five-hole probe nulling method reliable in complex flow field)

  • 김진권;강신형
    • 대한기계학회논문집B
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    • 제21권11호
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    • pp.1449-1457
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    • 1997
  • Since a non-nulling method of five-hole probes is valid only when the flow angle is within the calibrated angle range, it can not be used in a complex flow field. Full angle range pressure coefficient maps show that widely used nulling methods do not guarantee correct alignment of the probe with the flow direction in the unknown complex flow field. Zone decision method and features of zone map were studied by investigating the full angle range pressure coefficient maps. A reliable and efficient new nulling algorithm using zone decision by pressure ordering is proposed and verified. Since the zone decision method by pressure ordering can decide whether the flow is within the calibration angle range or not, it is useful in wide angle nonnulling methods, too.

비영위법에 의한 5공 프로브의 교정에 관한 연구 (A Study on the Five - hole Probe Calibration with Non-nulling Method)

  • 정양범;신영호;박호동
    • Journal of Advanced Marine Engineering and Technology
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    • 제20권2호
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    • pp.116-116
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    • 1996
  • This paper is concerned with a method for calibrating five-hole probes of both angle-tube and prismatic geometries to measure local total and static pressures and the magnitude and direction of the mean velocity vector. Descriptions of the calibration technique, the typical calibration data, and an accompanying discussion of the interpolation procedure are included. The flow properties are determined explicitly from measured probe pressures using calibration data. Flow angles are obtained within the deviation angle of 1.0 degree and dynamic pressures within 0.03 with 95% certainty. The variations in the calibration data due to Reynolds number are also discussed. For the range of Reynolds number employed, no effect was detected on the pitch, yaw and total pressure coefficients. However, the static pressure coefficient showed change to cause minor variations in the magnitude of the calculated velocity vector. To account for these variations, average correction factors need to be incorporated into the static pressure coefficient.

비영위법에 의한 5공 프로브의 교정에 관한 연구 (A Study on the Five-hole Probe Calibration with Non-nulling Method)

  • 정양범;신영호;박호동
    • Journal of Advanced Marine Engineering and Technology
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    • 제20권2호
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    • pp.48-56
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    • 1996
  • This paper is concerned with a method for calibrating five-hole probes of both angle-tube and prismatic geometries to measure local total and static pressures and the magnitude and direction of the mean velocity vector. Descriptions of the calibration technique, the typical calibration data, and an accompanying discussion of the interpolation procedure are included. The flow properties are determined explicitly from measured probe pressures using calibration data. Flow angles are obtained within the deviation angle of 1.0 degree and dynamic pressures within 0.03 with 95% certainty. The variations in the calibration data due to Reynolds number are also discussed. For the range of Reynolds number employed, no effect was detected on the pitch, yaw abd total pressure coefficients. However, the static pressure coefficient showed change to cause minor variations in the magnitude of the calculated velocity vector. To account for these variations, average correction factors need to be incorporated into the static pressure coefficient.

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온풍난방기용 Gun식 가스버너의 스월유동장에 대한 5공압력프로브의 측정 (Measurements of Five-Hole Pressure Probe on Swirling Flow Fields of Gun-Type Gas Burner for Furnace)

  • 김장권;오석형
    • 대한기계학회논문집B
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    • 제38권12호
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    • pp.991-997
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    • 2014
  • 이 연구는 Gun식 가스버너의 스월유동장을 연소실과 화염이 없는 상태에서 직선형 5공압력프로브의 측정을 통해 고찰하였다. 직선형 5공압력프로브에 의한 속도 및 정압성분들은 넌널링 교정방법에 의해 연산하였으며, X형 열선프로브와 전산유체역학의 해석에 의한 결과들과 비교하였다. 결과적으로 Gun식 가스버너의 중심부에서 스월유동장에 대해 5공압력프로브에 의한 속도 및 정압의 측정값들은 비교적 X형 열선프로브에 의한 경우보다는 좋은 성능을 보였으나 전산유체역학의 해석에 의한 경우보다는 다소 미흡한 결과를 보였다.

직선형 5공 압력프로브의 새로운 교정 알고리듬 적용 (Application of the New Calibration Algorithm of a Straight-Type Five-Hole Pressure Probe)

  • 김장권;오석형
    • 대한기계학회논문집B
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    • 제32권11호
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    • pp.863-869
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    • 2008
  • This paper investigated the new calibration algorithm of a straight-type five-hole pressure probe for measuring three-dimensional flow velocity components. This new calibration algorithm was used for velocity data reduction from the calibration map and based on the combination of a look-up, a binary search algorithm and a geometry transformation including the translation and reflection of nodes in a calibration map. The calibration map was expanded up to the application angle, ${\pm}55^{\circ}$ of a probe. This velocity data reduction method showed a perfect performance without any kind of interpolating errors in calculating yaw and pitch angles from the calibration map. Moreover, when it was applied to an actual flow field including a swirling flow, a good result came out on the whole.

직선형 5공 압력프로브를 이용한 3차원 유동속도 계측시스템 개발 (Measurement System Development for Three-Dimensional Flow Velocity Components Using Straight-Type Five-Hole Pressure Probe)

  • 김장권;정규조;오석형
    • 동력기계공학회지
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    • 제10권4호
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    • pp.56-64
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    • 2006
  • This paper shows the development process of a straight-type five-hole pressure probe for measuring three-dimensional flow velocity components. The data reduction method using a bi-cubic curve-fitting program in a new calibration map was introduced in this study. This new calibration map can be applied up to the application angle, ${\pm}55^{\circ}$ of a probe. As a result, for the application angle of ${\pm}45^{\circ}$, an error for yaw and pitch angles appeared from $-1.76^{\circ}\;to\;1.83^{\circ}$ and from $-1.91^{\circ}\;to\;1.75^{\circ}$, respectively. Moreover, an error for a vector magnitude and a static pressure compared with a dynamic one showed from -7.83% to 4.87% and from -0.73 to 0.77, respectively. Even though this data reduction method showed unsatisfactory errors in a vector magnitude, it resulted in an easy and simple application method. Especially, when it was applied to an actual flow field including a swirling flow, a good result came out on the whole. However, in order to obtain a better result, it is thought that a more sophisticated interpolation method needs to be introduced.

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5공 피토관 및 회전 열선 유속계에 의한 축류 홴 내부 유동장 계측 및 평가 (Flow Measurements and Performance Analysis using a 5-Hole Pitot Tube and a Rotating Hot-Wire Probe in an Axial Flow Fan)

  • 장춘만;김광용
    • 대한기계학회논문집B
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    • 제27권12호
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    • pp.1750-1757
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    • 2003
  • This paper describes the flow measurements inside the blade passage of an axial flow fan by using a rotating hot-wire probe sensor from a relative flame of reference fixed to the rotor blades. The validity of fan rotor designed by a streamline curvature equation was performed by the measurement of the three-dimensional flow upstream and downstream of the fan rotor using a 5-hole pitot tube. The vortical flow structure near the rotor tip can be clearly observed by the measurements of a relative velocity and its fluctuation on quasi-orthogonal planes to a tip leakage vortex. Larger vortical flow, which results in higher blockage in the main flow, is formed according to decrease a flow rate. The vortical flow spreads out to the 30 percent span from the rotor tip at near stall condition. In the design operating condition, the tip leakage vortex is moved downstream while the center of the vortex keeps constant in the spanwise direction. Detailed characteristics of a velocity fluctuation with relation to the vortex were also analyzed.

가시화와 5공 프로브 측정을 통한 연장된 앞전을 갖는 편요된 델타형 날개에서의 와류 상호작용 관찰 (Observation of the Vortex Interaction over an Yawed Delta Wing with Leading Edge Extension by Flow Visualization and 5-hole Probe Measurements)

  • 손명환;이기영
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2001년도 추계학술대회논문집B
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    • pp.388-393
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    • 2001
  • An experimental study is conducted to investigate the interaction of vortices over a delta wing with leading edge extension(LEX) through the off-surface flow visualization and the 5-hole probe measurements of the wing wake region. Especially, the application of a new visualization technique is employed by ultrasonic humidifier water droplet and laser beam sheet. The results, both the off-surface visualization and the 5-hole probe, show that LEX tends to stabilize the vortices of the delta wing up to the high angle of attack even though the model is yawed. With increasing yaw, the windward leading edge vortex moves inward, and closer to the wing surface, while the leeward vortex moves outwards and away from the wing surface. The vortex interaction is promoted in the windward side, and is delayed in the leeward side.

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