An Experimental Study of Taylor Vortices and Turbulence in Flow Between Eccentric Rotating Cylinders

1968 ◽  
Vol 90 (1) ◽  
pp. 285-296 ◽  
Author(s):  
J. H. Vohr
Keyword(s):  
Experimental Study ◽  
Turbulent Flow ◽  
Friction Factor ◽  
Experimental Work ◽  
Reynolds Numbers ◽  
Taylor Vortex ◽  
Rotating Cylinders ◽  
Taylor Vortices ◽  
Torque Measurements ◽  
Factor Data

The critical speeds for onset of Taylor vortices inflow between eccentric rotating cylinders are determined by means of torque measurements for various eccentricity ratios and clearance ratios of the cylinders. Results are compared with the theoretical and experimental work of other investigators. Visual studies are made of the flow in both the Taylor vortex and turbulent flow regimes. Friction factor data are obtained for Reynolds numbers up to 40,000.

Visual Observations and Torque Measurements in the Taylor Vortex Regime Between Eccentric Rotating Cylinders

1971 ◽  
Vol 93 (1) ◽  
pp. 121-129 ◽  
Author(s):  
P. Castle ◽  
F. R. Mobbs ◽  
P. H. Markho
Keyword(s):  
Outer Cylinder ◽  
Taylor Vortex ◽  
Rotating Cylinders ◽  
Taylor Vortices ◽  
Torque Measurements ◽  
Good Agreement ◽  
Visual Observations

The instability of Taylor vortices in the flow between a stationary outer cylinder and an eccentric rotating inner cylinder has been investigated by visual observations and by torque measurements. It is shown that both a “weak” and “strong” wavy mode of instability can be detected by torque measurements, giving critical Taylor numbers in good agreement with visual observations.

scholarly journals Fluid friction between rotating cylinders I—Torque measurements

1936 ◽  
Vol 157 (892) ◽  
pp. 546-564 ◽  
Keyword(s):  
Reynolds Number ◽  
Turbulent Flow ◽  
Centrifugal Force ◽  
Outer Cylinder ◽  
Reynolds Numbers ◽  
Stream Line ◽  
Rotating Cylinders ◽  
Torque Measurements ◽  
Critical Reynolds Numbers ◽  
The Stability

The stability of fluid contained between concentric rotating cylinders has been investigated and it has been shown that, when only the inner cylinder rotates, the flow becomes unstable when a certain Reynolds number of the flow is exceeded. When the outer cylinder only is rotated, the flow is stable so far as disturbances of the type produced in the former case are concerned, but provided the Reynolds number of the flow exceeds a certain value, turbulence sets in. The object of the present experiments was partly to measure the torque reaction between two cylinders in the two cases in order to find the effect of centrifugal force on the turbulence, and partly to find the critical Reynolds numbers for the transition from stream-line to turbulent flow. The apparatus is shown diagrammatically in fig. 1.

Numerical and Experimental Analysis of Turbulent Flow in Corrugated Pipes

2010 ◽  
Vol 132 (7) ◽  
Author(s):  
Henrique Stel ◽  
Rigoberto E. M. Morales ◽  
Admilson T. Franco ◽  
Silvio L. M. Junqueira ◽  
Raul H. Erthal ◽  
...  
Keyword(s):  
Reynolds Number ◽  
Pressure Drop ◽  
Turbulent Flow ◽  
Friction Factor ◽  
Turbulence Models ◽  
Reynolds Numbers ◽  
Velocity Magnitude ◽  
Geometric Configurations ◽  
Corrugated Surfaces ◽  
Friction Factors

This article describes a numerical and experimental investigation of turbulent flow in pipes with periodic “d-type” corrugations. Four geometric configurations of d-type corrugated surfaces with different groove heights and lengths are evaluated, and calculations for Reynolds numbers ranging from 5000 to 100,000 are performed. The numerical analysis is carried out using computational fluid dynamics, and two turbulence models are considered: the two-equation, low-Reynolds-number Chen–Kim k-ε turbulence model, for which several flow properties such as friction factor, Reynolds stress, and turbulence kinetic energy are computed, and the algebraic LVEL model, used only to compute the friction factors and a velocity magnitude profile for comparison. An experimental loop is designed to perform pressure-drop measurements of turbulent water flow in corrugated pipes for the different geometric configurations. Pressure-drop values are correlated with the friction factor to validate the numerical results. These show that, in general, the magnitudes of all the flow quantities analyzed increase near the corrugated wall and that this increase tends to be more significant for higher Reynolds numbers as well as for larger grooves. According to previous studies, these results may be related to enhanced momentum transfer between the groove and core flow as the Reynolds number and groove length increase. Numerical friction factors for both the Chen–Kim k-ε and LVEL turbulence models show good agreement with the experimental measurements.

Taylor-vortex instability and annulus-length effects

1976 ◽  
Vol 75 (1) ◽  
pp. 1-15 ◽  
Author(s):  
J. A. Cole
Keyword(s):  
Critical Speed ◽  
Taylor Vortex ◽  
Vortex Instability ◽  
Critical Speeds ◽  
Taylor Vortices ◽  
Torque Measurements ◽  
Concentric Cylinders ◽  
Theoretical Predictions ◽  
Range Of Values ◽  
Visual Observations

Critical speeds for the onset of Taylor vortices and for the later development of wavy vortices have been determined from torque measurements and visual observations on concentric cylinders of radius ratios R1/R2 = 0·894–0·954 for a range of values of the clearance c and length L: c/R1 = 0·0478–0·119 and L/c = 1–107. Effectively zero variation of the Taylor critical speed with annulus length was observed. The speed at the onset of wavy vortices was found to increase considerably as the annulus length was reduced and theoretical predictions are realistic only for L/c values exceeding say 40. The results were similar for all four clearance ratios examined. Preliminary measurements on eccentrically positioned cylinders with c/R1 = 0·119 showed corresponding effects.

Turbulent flow between counter-rotating concentric cylinders: a direct numerical simulation study

2008 ◽  
Vol 615 ◽  
pp. 371-399 ◽  
Author(s):  
S. DONG
Keyword(s):  
Turbulent Flow ◽  
Large Scale ◽  
Outer Cylinder ◽  
Three Dimensional ◽  
Reynolds Numbers ◽  
Taylor Vortex ◽  
Small Scale ◽  
Mean Flow ◽  
Concentric Cylinders ◽  
High Reynolds

We report three-dimensional direct numerical simulations of the turbulent flow between counter-rotating concentric cylinders with a radius ratio 0.5. The inner- and outer-cylinder Reynolds numbers have the same magnitude, which ranges from 500 to 4000 in the simulations. We show that with the increase of Reynolds number, the prevailing structures in the flow are azimuthal vortices with scales much smaller than the cylinder gap. At high Reynolds numbers, while the instantaneous small-scale vortices permeate the entire domain, the large-scale Taylor vortex motions manifested by the time-averaged field do not penetrate a layer of fluid near the outer cylinder. Comparisons between the standard Taylor–Couette system (rotating inner cylinder, fixed outer cylinder) and the counter-rotating system demonstrate the profound effects of the Coriolis force on the mean flow and other statistical quantities. The dynamical and statistical features of the flow have been investigated in detail.

Effects of Roughness on Turbulent Flow in Microchannels and Minichannels

2008 ◽  
Author(s):  
Timothy P. Brackbill ◽  
Satish G. Kandlikar
Keyword(s):  
Experimental Study ◽  
Laminar Flow ◽  
Turbulent Flow ◽  
Roughness Parameter ◽  
Reynolds Numbers ◽  
Turbulent Regime ◽  
Roughness Effects ◽  
Relative Roughness ◽  
Roughness Elements ◽  
Moody Diagram

The effect of roughness ranging from smooth to 24% relative roughness on laminar flow has been examined in previous works by the authors. It was shown that using a constricted parameter, εFP, the laminar results were predicted well in the roughened channels ([1],[2],[3]). For the turbulent regime, Kandlikar et al. [1] proposed a modified Moody diagram by using the same set of constricted parameters, and using the modification of the Colebrook equation. A new roughness parameter εFP was shown to accurately portray the roughness effects encountered in laminar flow. In addition, a thorough look at defining surface roughness was given in Young et al. [4]. In this paper, the experimental study has been extended to cover the effects of different roughness features on pressure drop in turbulent flow and to verify the validity of the new parameter set in representing the resulting roughness effects. The range of relative roughness covered is from smooth to 10.38% relative roughness, with Reynolds numbers up to 15,000. It was found that using the same constricted parameters some unique characteristics were noted for turbulent flow over sawtooth roughness elements.

Thermal and Friction Factor Data for Three Packed Block Construction Wavy Fin Surfaces

1994 ◽  
Vol 208 (3) ◽  
pp. 225-229 ◽  
Author(s):  
R J Gough BEng ◽  
T T Al-Shemmeri
Keyword(s):  
Reynolds Number ◽  
Heat Exchanger ◽  
Wind Tunnel ◽  
Friction Factor ◽  
Experimental Work ◽  
Performance Data ◽  
Wavy Surfaces ◽  
Block Construction ◽  
Factor Data

This paper describes an experimental work undertaken to determine performance data for packed block wavy fins. A purpose-built heat exchanger testing wind tunnel was used to investigate three wavy surfaces. The data were then presented in the form of Colburn (j) factors and friction (f) factors versus Reynolds number. Results showed a favourable comparison with published works pertaining to similar surface geometries; in addition, geometries were also tested which varied considerably from those in the literature to date.

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