Turbine Flowmeter Performance Model

1970 ◽  
Vol 92 (4) ◽  
pp. 712-722 ◽  
Author(s):  
R. E. Thompson ◽  
J. Grey
Keyword(s):  
Reynolds Number ◽  
Velocity Profile ◽  
High Reynolds Number ◽  
Performance Model ◽  
Interference Effects ◽  
Rotor Speed ◽  
Number Range ◽  
Drag Forces ◽  
High Reynolds ◽  
Lift And Drag

A theoretical model of a turbine meter operating in the high Reynolds number regime has been formulated to study the effects of retarding torques, inlet velocity profile, blade interference effects, meter geometry, and other factors. A computer program predicts actual rotor speed by numerical integration of the lift and drag forces on the rotor blade. Numerical sample calculations indicated substantial effects due to velocity profile and blade interference. Retarding torques were relatively unimportant in the high Reynolds number range.

scholarly journals Numerical Investigation of the Flow around a Feather Shuttlecock with Rotation

Proceedings ◽  
2020 ◽  
Vol 49 (1) ◽  
pp. 28
Author(s):  
John Hart ◽  
Jonathan Potts
Keyword(s):  
Reynolds Number ◽  
Wind Tunnel ◽  
Drag Coefficient ◽  
Numerical Investigation ◽  
Computational Fluid Dynamic ◽  
High Reynolds Number ◽  
Fluid Dynamic ◽  
Flow Structures ◽  
Drag Forces ◽  
High Reynolds

This paper presents the first scale resolving computational fluid dynamic (CFD) investigation of a geometrically realistic feather shuttlecock with rotation at a high Reynolds number. Rotation was found to reduce the drag coefficient of the shuttlecock. However, the drag coefficient is shown to be independent of the Reynolds number for both rotating and statically fixed shuttlecocks. Particular attention is given to the influence of rotation on the development of flow structures. Rotation is shown to have a clear influence on the formation of flow structures particularly from the feather vanes, and aft of the shuttlecock base. This further raises concerns regarding wind tunnel studies that use traditional experimental sting mounts; typically inserted into this aft region, they have potential to compromise both flow structure and resultant drag forces. As CFD does not necessitate use of a sting with proper application, it has great potential for a detailed study and analysis of shuttlecocks.

Stability of non-parabolic flow in a flexible tube

1999 ◽  
Vol 395 ◽  
pp. 211-236 ◽  
Author(s):  
V. SHANKAR ◽  
V. KUMARAN
Keyword(s):  
Reynolds Number ◽  
Velocity Profile ◽  
Asymptotic Analysis ◽  
High Reynolds Number ◽  
Reynolds Numbers ◽  
Flexible Tube ◽  
Developing Flow ◽  
Parabolic Flow ◽  
High Reynolds ◽  
The Stability

Flows with velocity profiles very different from the parabolic velocity profile can occur in the entrance region of a tube as well as in tubes with converging/diverging cross-sections. In this paper, asymptotic and numerical studies are undertaken to analyse the temporal stability of such ‘non-parabolic’ flows in a flexible tube in the limit of high Reynolds numbers. Two specific cases are considered: (i) developing flow in a flexible tube; (ii) flow in a slightly converging flexible tube. Though the mean velocity profile contains both axial and radial components, the flow is assumed to be locally parallel in the stability analysis. The fluid is Newtonian and incompressible, while the flexible wall is modelled as a viscoelastic solid. A high Reynolds number asymptotic analysis shows that the non-parabolic velocity profiles can become unstable in the inviscid limit. This inviscid instability is qualitatively different from that observed in previous studies on the stability of parabolic flow in a flexible tube, and from the instability of developing flow in a rigid tube. The results of the asymptotic analysis are extended numerically to the moderate Reynolds number regime. The numerical results reveal that the developing flow could be unstable at much lower Reynolds numbers than the parabolic flow, and hence this instability can be important in destabilizing the fluid flow through flexible tubes at moderate and high Reynolds number. For flow in a slightly converging tube, even small deviations from the parabolic profile are found to be sufficient for the present instability mechanism to be operative. The dominant non-parallel effects are incorporated using an asymptotic analysis, and this indicates that non-parallel effects do not significantly affect the neutral stability curves. The viscosity of the wall medium is found to have a stabilizing effect on this instability.

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.

1502 Universality of the velocity profile in the high Reynolds number turbulent pipe flow

2015 ◽  
Vol 2015 (0) ◽  
pp. _1502-1_-_1502-2_
Author(s):  
Yuki WADA ◽  
Noriyuki FURUICHI ◽  
Yoshiya TERAO ◽  
Yoshiyuki TSUJI
Keyword(s):  
Reynolds Number ◽  
Velocity Profile ◽  
Pipe Flow ◽  
High Reynolds Number ◽  
Turbulent Pipe Flow ◽  
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.

scholarly journals Experimental study on the mean velocity profile in the high Reynolds number turbulent pipe flow

2015 ◽  
Vol 81 (826) ◽  
pp. 15-00091-15-00091 ◽  
Author(s):  
Yuki WADA ◽  
Noriyuki FURUICHII ◽  
Yoshiya TERAO ◽  
Yoshiyuki TSUJI
Keyword(s):  
Experimental Study ◽  
Reynolds Number ◽  
Velocity Profile ◽  
Pipe Flow ◽  
High Reynolds Number ◽  
Turbulent Pipe Flow ◽  
Mean Velocity ◽  
The Mean ◽  
High Reynolds

Further experiments for mean velocity profile of pipe flow at high Reynolds number

2018 ◽  
Vol 30 (5) ◽  
pp. 055101 ◽  
Author(s):  
N. Furuichi ◽  
Y. Terao ◽  
Y. Wada ◽  
Y. Tsuji
Keyword(s):  
Reynolds Number ◽  
Velocity Profile ◽  
Pipe Flow ◽  
High Reynolds Number ◽  
Mean Velocity ◽  
High Reynolds

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.

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