Drag of a sphere in dilute polymer solutions in high Reynolds number range

1998 ◽  
Vol 37 (4) ◽  
pp. 328-335 ◽  
Author(s):  
K. Watanabe ◽  
Hiroto Kui ◽  
Ikumi Motosu
Keyword(s):  
Reynolds Number ◽  
High Reynolds Number ◽  
Polymer Solutions ◽  
Number Range ◽  
Dilute Polymer Solutions ◽  
Reynolds Number Range ◽  
High Reynolds

Experimental Results of Flow Nozzle Based on PTC 6 for High Reynolds Number

2014 ◽  
Author(s):  
Noriyuki Furuichi ◽  
Kar-Hooi Cheong ◽  
Yoshiya Terao ◽  
Shinichi Nakao ◽  
Keiji Fujita ◽  
...  
Keyword(s):  
Reynolds Number ◽  
High Reynolds Number ◽  
Discharge Coefficient ◽  
Experimental Results ◽  
Flow Conditions ◽  
Number Range ◽  
Discharge Coefficients ◽  
Reynolds Number Range ◽  
Lower Reynolds Number ◽  
High Reynolds

Discharge coefficients for three flow nozzles based on ASME PTC 6 are measured under many flow conditions at AIST, NMIJ and PTB. The uncertainty of the measurements is from 0.04% to 0.1% and the Reynolds number range is from 1.3×105 to 1.4×107. The discharge coefficients obtained by these experiments is not exactly consistent to one given by PTC 6 for all examined Reynolds number range. The discharge coefficient is influenced by the size of tap diameter even if at the lower Reynolds number region. Experimental results for the tap of 5 mm and 6 mm diameter do not satisfy the requirements based on the validation procedures and the criteria given by PTC 6. The limit of the size of tap diameter determined in PTC 6 is inconsistent with the validation check procedures of the calibration result. An enhanced methodology including the term of the tap diameter is recommended. Otherwise, it is recommended that the calibration test should be performed at as high Reynolds number as possible and the size of tap diameter is desirable to be as small as possible to obtain the discharge coefficient with high accuracy.

Further Investigation of Discharge Coefficient for PTC 6 Flow Nozzle in High Reynolds Number

2015 ◽  
Author(s):  
Noriyuki Furuichi ◽  
Yoshiya Terao ◽  
Shinichi Nakao ◽  
Keiji Fujita ◽  
Kazuo Shibuya
Keyword(s):  
Reynolds Number ◽  
Turbulent Flow ◽  
High Reynolds Number ◽  
Discharge Coefficient ◽  
Flow Region ◽  
Number Range ◽  
Discharge Coefficients ◽  
Reynolds Number Range ◽  
High Reynolds

The discharge coefficients of the throat tap flow nozzle based on ASME PTC 6 are measured in wide Reynolds number range from Red=5.8×104 to Red=1.4×107. The nominal discharge coefficient (the discharge coefficient without tap) is determined from the discharge coefficients measured for different tap diameters. The tap effects are correctly obtained by subtracting the nominal discharge coefficient from the discharge coefficient measured. Finally, by combing the nominal discharge coefficient and the tap effect determined in three flow regions, that is, laminar, transitional and turbulent flow region, the new equations of the discharge coefficient are proposed in three flow regions.

scholarly journals Drag Reduction of Circular Cylinder in the High-Reynolds-Number Range.

1993 ◽  
Vol 59 (558) ◽  
pp. 342-348 ◽  
Author(s):  
Tsutomu Adachi ◽  
Hiroyuki Maeda ◽  
Masamitsu Shiono ◽  
Tetsuo Ozaki ◽  
Kazuo Matsuuchi ◽  
...  
Keyword(s):  
Reynolds Number ◽  
Circular Cylinder ◽  
Drag Reduction ◽  
High Reynolds Number ◽  
Number Range ◽  
Reynolds Number Range ◽  
High Reynolds

The effects of surface roughness on the flow past circular cylinders at high Reynolds numbers

1982 ◽  
Vol 123 ◽  
pp. 363-378 ◽  
Author(s):  
Y. Nakamura ◽  
Y. Tomonari
Keyword(s):  
Reynolds Number ◽  
Circular Cylinder ◽  
High Reynolds Number ◽  
Circular Cylinders ◽  
Similarity Parameter ◽  
Number Range ◽  
Pressure Distributions ◽  
Mean Pressure ◽  
Supercritical Range ◽  
High Reynolds

Measurements of’ the mean-pressure distribution and the Strouhal number on a smooth circular cylinder, circular cylinders with distributed roughness, and circular cylinders with narrow roughness strips were made over a Reynolds-number range 4.0 × l04 to 1.7 × l06 in a uniform flow. A successful high-Reynolds-number (trans- critical) simulation for a smooth circular cylinder is obtained using a smooth circular cylinder with roughness strips. High-Reynolds-number simulation can only be obtained by roughness strips and not by distributed roughness. A similarity parameter correlating the pressure distributions on circular cylinders with distributed roughness in the supercritical range is presented. The same parameter can also be applicable to the drag coefficients of spheres with distributed roughness.

Planar Oscillatory Flow Forces at High Reynolds Numbers

1993 ◽  
Vol 115 (1) ◽  
pp. 31-39 ◽  
Author(s):  
J. R. Chaplin
Keyword(s):  
Surface Roughness ◽  
Reynolds Number ◽  
Circular Cylinder ◽  
Oscillatory Flow ◽  
Reynolds Numbers ◽  
Number Range ◽  
High Reynolds Numbers ◽  
Reynolds Number Range ◽  
Fine Surface ◽  
High Reynolds

Measurements of pressures around a circular cylinder with fine surface roughness in planar oscillatory flow reveal considerable changes in drag and inertia coefficients over the Reynolds number range 2.5 × 105 to 7.5 × 105, and at Keulegan-Carpenter numbers between 5 and 25. In most respects, these results are shown to be compatible with previous measurements in planar oscillatory flow, and with previous measurements in which the same 0.5-m-dia cylinder was tested in waves.

Investigation of internal intermittency by way of higher-order spectral moments

2021 ◽  
Vol 932 ◽  
Author(s):  
S. Lortie ◽  
L. Mydlarski
Keyword(s):  
Reynolds Number ◽  
High Reynolds Number ◽  
Scalar Fields ◽  
Passive Scalar ◽  
Higher Order ◽  
Inertial Subrange ◽  
Grid Turbulence ◽  
Spectral Moments ◽  
Number Range ◽  
High Reynolds

The analysis of turbulence by way of higher-order spectral moments is uncommon, despite the relatively frequent use of such statistical analyses in other fields of physics and engineering. In this work, higher-order spectral moments are used to investigate the internal intermittency of the turbulent velocity and passive-scalar (temperature) fields. This study first introduces the theory behind higher-order spectral moments as they pertain to the field of turbulence. Then, a short-time Fourier-transform-based method is developed to estimate these higher-order spectral moments and provide a relative, scale-by-scale measure of intermittency. Experimental data are subsequently analysed and consist of measurements of homogeneous, isotropic, high-Reynolds-number, passive and active grid turbulence over the Reynolds-number range $35\leq R_{\lambda } \leq ~731$ . Emphasis is placed on third- and fourth-order spectral moments using the definitions formalised by Antoni (Mech. Syst. Signal Pr., vol. 20 (2), 2006, pp. 282–307), as such statistics are sensitive to transients and provide insight into deviations from Gaussian behaviour in grid turbulence. The higher-order spectral moments are also used to investigate the Reynolds (Péclet) number dependence of the internal intermittency of velocity and passive-scalar fields. The results demonstrate that the evolution of higher-order spectral moments with Reynolds number is strongly dependent on wavenumber. Finally, the relative levels of internal intermittency of the velocity and passive-scalar fields are compared and a higher level of internal intermittency in the inertial subrange of the scalar field is consistently observed, whereas a similar level of internal intermittency is observed for the velocity and passive-scalar fields for the high-Reynolds-number cases as the Kolmogorov length scale is approached.

Scaling of the wall-normal turbulence component in high-Reynolds-number pipe flow

2007 ◽  
Vol 576 ◽  
pp. 457-473 ◽  
Author(s):  
RONGRONG ZHAO ◽  
ALEXANDER J. SMITS
Keyword(s):  
Reynolds Number ◽  
Pipe Flow ◽  
High Reynolds Number ◽  
Reynolds Numbers ◽  
Constant Region ◽  
Intensity Data ◽  
Number Range ◽  
Outer Flow ◽  
High Reynolds ◽  
Wavenumber Region

Streamwise and wall-normal turbulence components are obtained in fully developed turbulent pipe over a Reynolds number range from 1.1 × 105to 9.8 × 106. The streamwise intensity data are consistent with previous measurements in the same facility. For the wall-normal turbulence intensity, a constant region inv'r.m.s.is found for the region 200 ≤ y+≤ 0.1R+for Reynolds numbers up to 1.0 × 106. An increase inv'r.m.s.is observed below abouty+∼ 100, although additional measurements will be required to establish its generality. The wall-normal spectra collapse in the energy-containing region with inner scaling, but for the low-wavenumber region ay/Rdependence is observed, which also indicates a continuing influence from the outer flow on the near-wall motions.

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