• Title/Summary/Keyword: Non-Nulling Calibration

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Reynolds Number Effects on the Non-Nulling Calibration of a Cone-Type Five-Hole Probe for Turbomachinery Applications

  • Lee, Sang-Woo;Jun, Sang-Bae
    • Journal of Mechanical Science and Technology
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    • v.19 no.8
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    • pp.1632-1648
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    • 2005
  • The effects of Reynolds number on the non-nulling calibration of a typical cone-type five-hole probe have been investigated for the representative Reynolds numbers in turbomachinery. The pitch and yaw angles are changed from - 35 degrees to 35 degrees with an angle interval of 5 degrees at six probe Reynolds numbers in range between $6.60{\times}10^3\;and\;3.17{\times}10^4$. The result shows that not only each calibration coefficient itself but also its Reynolds number dependency is affected significantly by the pitch and yaw angles. The Reynolds-number effects on the pitch- and yaw-angle coefficients are noticeable when the absolute values of the pitch and yaw angles are smaller than 20 degrees. The static-pressure coefficient is sensitive to the Reynolds number nearly all over the pitch- and yaw-angle range. The Reynolds-number effect on the total-pressure coefficient is found remarkable when the absolute values of the pitch and yaw angles are larger than 20 degrees. Through a typical non-nulling reduction procedure, actual reduced values of the pitch and yaw angles, static and total pressures, and velocity magnitude at each Reynolds number are obtained by employing the calibration coefficients at the highest Reynolds number ($Re=3.17{\times}10^4$) as input reference calibration data. As a result, it is found that each reduced value has its own unique trend depending on the pitch and yaw angles. Its general tendency is related closely to the variation of the corresponding calibration coefficient with the Reynolds number. Among the reduced values, the reduced total pressure suffers the most considerable deviation from the measured one and its dependency upon the pitch and yaw angles is most noticeable. In this study, the root-mean-square data as well as the upper and lower bounds of the reduced values are reported as a function of the Reynolds number. These data would be very useful in the estimation of the Reynolds-number effects on the non-nulling calibration.

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

  • Kim, Jang-Kweon;Oh, Seok-Hyung
    • Journal of Power System Engineering
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    • v.19 no.1
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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.

The Effect of Reynolds Number on the Calibration of a Five-Hole Probe at Low Reynolds Numbers (저 Reynolds 수 영역에서 Reynolds 수가 5공 프로우브의 보정에 미치는 영향)

  • Lee, Sang Woo;Jun, Sang Dae
    • 유체기계공업학회:학술대회논문집
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    • 2000.12a
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    • pp.193-199
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    • 2000
  • The effects of Reynolds number on the non-nulling calibration of a cone-type five-hole probe in low-speed flows have been investigated at the Reynolds numbers of $2.04{\times}10^3,\;4.09{\times}10^3$, and $6.13{\times}10^3$. The calibration is conducted at the pitch and yaw angles in ranges between -35 degrees and 35 degrees with an angle interval of 5 degrees. The result shows that each calibration coefficient, in general, is a function of the pitch and yaw angles, so that the pre-existing calibration data in a nulling mode are not enough in accounting for the full non-nulling calibration characteristics. Due to the interference of the probe stem, the calibration coefficients have more Reynolds number sensitivity at positive pitch angles than at negative ones.

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

  • Kim, Jang Kweon;Oh, Seok Hyung
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.38 no.12
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    • pp.991-997
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    • 2014
  • This study investigated the swirling flow fields of a gun-type gas burner (GTGB) without a combustion chamber under cold flow conditions. Three velocity components and the static pressure were measured with a straight-type five-hole pressure probe (GHPP) using a non-nulling calibration method and compared with the results of an X-type hot-wire probe (X-probe) and computational fluid dynamics (CFD). The GHPP measured the velocity and static pressure for the swirling flow of the central region of the GTGB better than the X-probe but produced slightly worse results than the CFD.

The Effect of Reynolds Number on the Three-Dimensional Flow Measurements with a Two-Stage Cone-Type Five-Hole Probe in a Non-Nulling Mode (Reynolds 수가 2단 원추형 5공프로브를 이용한 3차원 유동 측정에 미치는 영향 - 저속 유동장에서의 보정 결과 -)

  • Lee, Sang-U;Jeon, Sang-Bae
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.26 no.1
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    • pp.27-38
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    • 2002
  • The effects of Reynolds number on the non-nulling calibrations of a cone-type ave-type probe in low-speed flows have been investigated at Reynolds numbers of 2.04$\times$10$^3$, 4.09$\times$10$^3$and 6.13$\times$10$^3$. The calibration is conducted at the pitch and yaw angles in ranges between -35 degrees and 35 degrees with an angle interval of 5 degrees. In addition to the calibration coefficients, reduced pitch and yaw angles, static and total pressures, and velocity magnitude are obtained through a typical non-nulling reduction procedure. The result shows that each calibration coefficient, in general, is a function of both the pitch and yaw angles, so that the pre-existing calibration data in a nulling mode are not enough in accounting far the full non-nulling calibration characteristics. Due to interference of the probe stem, the calibration coefficient are more sensitive to Reynolds number at positive pitch angles than at negative ones. The calibration data reduced in this study may serve as a guide line in the estimation of uncertainty intervals resulted from the Reynolds number effects at low Reynolds numbers.