Discussion: “Experimental and Analytical Sonic Nozzle Discharge Coefficients for Reynolds Numbers up to 8×106” (Szaniszlo, A. J., 1975, ASME J. Eng. Power, 97, pp. 521–525)

1975 ◽  
Vol 97 (4) ◽  
pp. 525-525
Author(s):  
H. Schroyer
1975 ◽  
Vol 97 (4) ◽  
pp. 521-525 ◽  
Author(s):  
A. J. Szaniszlo

Sonic discharge coefficients are presented for two different geometry flow nozzles using nitrogen gas at high pressures (100 atm (100 × 105N/m2)) where real-gas corrections are significant. Throat Reynolds number range extended up to 8 × 106. Experimentally obtained coefficients for a nozzle with a continuous and finite radius of curvature agreed with those obtained analytically to within 0.2 percent. Experimental coefficients for a long-radius ASME nozzle agreed to within 1/4 percent to an empirical equation representing the most probable subsonic discharge coefficient.


1989 ◽  
Vol 111 (1) ◽  
pp. 22-33
Author(s):  
V. C. Ting ◽  
J. J. S. Shen

This paper presents the orifice calibration results for nominal 15.24, 10.16, and 5.08-cm (6, 4, 2-in.) orifice meters conducted at the Chevron’s Sand Hills natural gas flow measurement facility in Crane, Texas. Over 200 test runs were collected in a field environment to study the accuracy of the orifice meters. Data were obtained at beta ratios ranging from 0.12 to 0.74 at the nominal conditions of 4576 kPa and 27°C (650 psig and 80°F) with a 0.57 specific gravity processed, pipeline quality natural gas. A bank of critical flow nozzles was used as the flow rate proving device to calibrate the orifice meters. Orifice discharge coefficients were computed with ANSI/API 2530-1985 (AGA3) and ISO 5167/ASME MFC-3M-1984 equations for every set of data points. The uncertainty of the calibration system was analyzed according to The American National Standard (ANSI/ASME MFC-2M-A1983). The 10.16 and 5.08-cm (4 and 2-in.) orifice discharge coefficients agreed with the ANSI and ISO standards within the estimated uncertainty level. However, the 15.24-cm (6-in.) meter deviated up to − 2 percent at a beta ratio of 0.74. With the orifice bore Reynolds numbers ranging from 1 to 9 million, the Sand Hills calibration data bridge the gap between the Ohio State water data at low Reynolds numbers and Chevron’s high Reynolds number test data taken at a larger test facility in Venice, Louisiana. The test results also successfully demonstrated that orifice meters can be accurately proved with critical flow nozzles under realistic field conditions.


2004 ◽  
Vol 126 (4) ◽  
pp. 803-808 ◽  
Author(s):  
M. Dittmann ◽  
K. Dullenkopf ◽  
S. Wittig

The secondary air system of modern gas turbine engines consists of numerous stationary or rotating passages to transport the cooling air, taken from the compressor, to thermally high loaded components that need cooling. Thereby the cooling air has to be metered by orifices to control the mass flow rate. Especially the discharge behavior of rotating holes may vary in a wide range depending on the actual geometry and the operating point. The exact knowledge of the discharge coefficients of these orifices is essential during the design process in order to guarantee a well adapted distribution of the cooling air inside the engine. This is crucial not only for a safe and efficient operation but also fundamental to predict the component’s life and reliability. In this paper two different methods to correlate discharge coefficients of rotating orifices are described and compared, both in the stationary and rotating frame of reference. The benefits of defining the discharge coefficient in the relative frame of reference will be pointed out. Measurements were conducted for two different length-to-diameter ratios of the orifices with varying inlet geometries. The pressure ratio across the rotor was varied for rotational Reynolds numbers up to ReΦ=8.6×105. The results demonstrate the strong influence of rotation on the discharge coefficient. An analysis of the complete data shows significant optimizing capabilities depending on the orifice geometry.


Author(s):  
M. Dittmann ◽  
K. Dullenkopf ◽  
S. Wittig

The secondary air system of modern gas turbine engines consists of numerous stationary or rotating passages to transport the cooling air, taken from the compressor, to thermally high loaded components that need cooling. Thereby the cooling air has to be metered by orifices to control the mass flow rate. Especially the discharge behavior of rotating holes may vary in a wide range depending on the actual geometry and the operating point. The exact knowledge of the discharge coefficients of these orifices is essential during the design process in order to guarantee a well adapted distribution of the cooling air inside the engine. This is crucial not only for a safe and efficient operation but also fundamental to predict the component’s life and reliability. In this paper two different methods to correlate discharge coefficients of rotating orifices are described and compared, both in the stationary and rotating frame of reference. The benefits of defining the discharge coefficient in the relative frame of reference will be pointed out. Measurements were conducted for two different length-to-diameter ratios of the orifices with varying inlet geometries. The pressure ratio across the rotor was varied for rotational Reynolds numbers up to Reφ = 8:6 × 105. The results demonstrate the strong influence of rotation on the discharge coefficient. An analysis of the complete data shows significant optimising capabilities depending on the orifice geometry.


1965 ◽  
Vol 7 (2) ◽  
pp. 210-219 ◽  
Author(s):  
A. Lichtarowicz ◽  
R. K. Duggins ◽  
E. Markland

The results of a number of previous investigations of the discharge characteristics of parallel-bore orifices with length/diameter ratios up to 10 and Reynolds numbers up to about 105are collected and discussed, together with new data which extend to Reynolds number as low as unity. Simple empirical expressions, which fit the data well, are suggested for design purposes.


Author(s):  
Masahiro Ishibashi ◽  
Toshihiro Morioka ◽  
B. Thomas Arnberg

The effect of the inlet curvature R on the discharge coefficients of toroidal throat critical flow Venturi nozzles is discussed based on calibration results of high-precision nozzles HPNs with R = 1.0, 1.2, 1.5, 1.8, 2.0, and 2.5D, where D is the throat diameter (9.6, 13.4, and 18.9 mm). The Reynolds numbers RD range from 1.2×105 to 1.2×106, corresponding to absolute upstream pressures of 0.1 to 0.7 MPa. The calibrations were performed by a constant volume tank system developed for the primary standard in Japan.


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