Module Friction Factors and Intramodular Pressure Distributions for Periodic Fully Developed Turbulent Flow in Rectangular Interrupted-Plate Ducts

1988 ◽  
Vol 110 (2) ◽  
pp. 147-154 ◽  
Author(s):  
R. K. McBrien ◽  
B. R. Baliga
Keyword(s):  
Turbulent Flows ◽  
Static Pressure ◽  
Rectangular Cross Section ◽  
Reynolds Numbers ◽  
Plate Spacing ◽  
Pressure Distributions ◽  
Geometric Configurations ◽  
Friction Factors ◽  
Mean Pressure ◽  
Fully Developed Turbulent Flow

This paper presents detailed time-mean pressure measurements for periodic fully developed turbulent flows in straight interrupted-plate ducts of rectangular cross section. Several combinations of plate spacing and duct aspect ratio are investigated for Reynolds numbers, based on a module hydraulic diameter, in the range 5000 to 45000. The experiments undertaken in this work establish the existence of steady, time-mean, periodic fully developed flows for all flow rates and geometric configurations investigated. The results include graphical and tabular presentations of module friction factor versus Reynolds number data, and intramodular time-mean wall static pressure distributions. The physical implications of these results are also discussed.

Time-Mean Wall Static Pressure Distributions and Module Friction Factors for Fully Developed Flows in a Rectangular Duct With Spatially Periodic Interrupted-Plate Inserts

2003 ◽  
Author(s):  
Jose´ A. Candanedo ◽  
Emile Aboumansour ◽  
B. Rabi Baliga
Keyword(s):  
Reynolds Number ◽  
Static Pressure ◽  
Plate Thickness ◽  
Compact Heat Exchangers ◽  
Plate Length ◽  
Plate Spacing ◽  
Pressure Distributions ◽  
Half Height ◽  
Friction Factors ◽  
Spatially Periodic

An experimental study of fully developed flows of air in straight rectangular ducts with interrupted-plate inserts is presented. These flows have features akin to those produced in the cores of plate-fin compact heat exchangers. In all, flows in one plain duct and six different ducts with interrupted-plate inserts were studied. Values of the dimensionless geometric parameters of the interrupted-plate ducts, normalized with respect to its half-height, are the following: width of the duct cross-section between 19.68 and 23.58; plate length between 3.286 and 3.938; plate thickness of 0.062, 0.115, and 0.205; and inter-plate spacing between 3.264 and 7.815. Values of the Reynolds number, based on a nominal average velocity and hydraulic diameter, ranged from 1663 to 30993. The results include graphical and tabular presentations of time-mean static pressure distributions along the axial centerline of the top wall of the duct, and module friction factor versus Reynolds number data, all in the periodic fully developed region.

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.

Measurement and Prediction of the Effects of Nonuniform Surface Roughness on Turbulent Flow Friction Coefficients

1988 ◽  
Vol 110 (4) ◽  
pp. 380-384 ◽  
Author(s):  
R. P. Taylor ◽  
W. F. Scaggs ◽  
H. W. Coleman
Keyword(s):  
Turbulent Flows ◽  
Rough Surfaces ◽  
Reynolds Numbers ◽  
Base Diameter ◽  
Friction Coefficients ◽  
Friction Factors ◽  
Random Rough Surfaces ◽  
The Status ◽  
Uniform Array ◽  
Prediction Approach

The status of prediction methods for friction coefficients in turbulent flows over nonuniform or random rough surfaces is reviewed. Experimental data for friction factors in fully developed pipe flows with Reynolds numbers between 10,000 and 600,000 are presented for two nonuniform rough surfaces. One surface was roughened with a mixture of cones and hemispheres which had the same height and base diameter and were arranged in a uniform array. The other surface was roughened with a mixture of two sizes of cones and two sizes of hemispheres. These data are compared with predictions made using the previously published discrete element prediction approach of Taylor, Coleman, and Hodge. The agreement between the data and the predictions is excellent.

On Transition From Supersonic to Subsonic Flow at Low Reynolds Numbers in a Tube

1969 ◽  
Vol 36 (2) ◽  
pp. 146-150 ◽  
Author(s):  
R. Y. Chen ◽  
J. C. Williams
Keyword(s):  
Mach Number ◽  
Static Pressure ◽  
Subsonic Flow ◽  
Supersonic Nozzle ◽  
Reynolds Numbers ◽  
Impact Pressure ◽  
Low Reynolds Numbers ◽  
Pressure Distributions ◽  
Low Reynolds ◽  
The Impact

A supersonic low-density gas stream produced in a supersonic nozzle was passed through a circular tube in which the transition from supersonic to subsonic flow took place. Static pressure distributions along the tube (and nozzle) and impact pressure distributions across the tube at several stations were measured to determine the nature of this transition. The impact pressure distributions were used, together with the local static pressure, to infer Mach number and velocity profiles in the tube. When the pressure distributions and center-line Mach number distributions are considered together, one obtains a fairly clear picture of the processes involved in the transition from supersonic to subsonic flow at low Reynolds numbers.

Pressure Loss Through Sharp 180 Deg Turns in Smooth Rectangular Channels

1984 ◽  
Vol 106 (3) ◽  
pp. 677-681 ◽  
Author(s):  
D. E. Metzger ◽  
C. W. Plevich ◽  
C. S. Fan
Keyword(s):  
Pressure Loss ◽  
Rectangular Cross Section ◽  
Reynolds Numbers ◽  
Internal Cooling ◽  
Turbine Engine ◽  
Pressure Distributions ◽  
Rectangular Channels ◽  
Flow Geometry ◽  
Loss Coefficients ◽  
Measured Pressure

Measured pressure distributions, pressure loss coefficients, and surface streamline visualizations are presented for 180 deg turns in smooth, rectangular cross-section channels. The flow geometry models situations that exist in multipass internal cooling of gas turbine engine airfoils. The turn geometry is characterized by parameters W*, the ratio of upstream and downstream channel widths; D*, the nondimensional channel depth; H*, the nondimensional clearance height at the tip of the turn; and R*, the nondimensional corner fillet radius. The present results cover a range of combinations of geometry parameters and Reynolds numbers to aid in prediction of coolant flow rates in present and future cooled airfoil designs.

Fluid Flow Structures in Staggered Banks of Cylinders Located in a Channel

1995 ◽  
Vol 117 (1) ◽  
pp. 36-44 ◽  
Author(s):  
M. J. Braun ◽  
V. V. Kudriavtsev
Keyword(s):  
Fluid Flow ◽  
Numerical Experiments ◽  
Reynolds Numbers ◽  
Flow Structures ◽  
Wall Jet ◽  
Square Channel ◽  
Pressure Distributions ◽  
Geometric Configurations ◽  
Model Fluid ◽  
Flow Through

This paper contains numerical experiments that model fluid flow through a staggered array of cylinders and represents a continuation of work previously performed by the authors (Braun et al., 1993; Kudriavstsev et al., 1993). The results shown here concentrate on the analysis of the physics of flow and pressure distribution in (i) one row of cylinders, and (ii) seven rows of cylinders. The test section is the same square channel described by Braun et al. (1993). The numerical experiments were run in transient mode at Reynolds numbers (Re = umaxd/v) ranging from 86 to 869. The primary purpose of this paper is to report qualitative results regarding the attached near-wall jet phenomenon and to discuss its flow mechanics. The authors compare various stages of the transient evolution of the flow structures for geometric configurations that contain one, and seven rows of pins respectively. The associated pressure distributions in the arrays of pins are also discussed.

scholarly journals Turbulent flows in channels and pipes

2007 ◽  
Vol 29 (3) ◽  
pp. 385-396
Author(s):  
Khanh Le Chau
Keyword(s):  
Variational Principle ◽  
Viscous Fluid ◽  
Turbulent Flows ◽  
Good Accuracy ◽  
Reynolds Numbers ◽  
Low Reynolds Numbers ◽  
Pipe Flows ◽  
High Reynolds Numbers ◽  
Friction Factors ◽  
High Reynolds

A variational principle for channel and pipe flows of incompressible viscous fluid is proposed. For low Reynolds numbers this variational principle reduces to the principle of minimum dissipation. For high Reynolds numbers it enables one to calculate the velocity profiles and the corresponding friction factors with reasonably good accuracy.

Predicted Secondary Flows in Triangular Array Rod Bundles

1979 ◽  
Vol 101 (3) ◽  
pp. 354-362 ◽  
Author(s):  
A. C. Trupp ◽  
A. M. M. Aly
Keyword(s):  
Secondary Flow ◽  
Reynolds Numbers ◽  
Flow Cell ◽  
Secondary Flows ◽  
Rod Bundles ◽  
Primary Flow ◽  
Friction Factors ◽  
Fully Developed Turbulent Flow ◽  
Flow Through ◽  
Stress Variations

A one-equation turbulence model was applied to forecast the main features of fully-developed turbulent flow through infinite equilateral triangular arrays of parallel rods having pitch-to-diameter ratios of 1.12 – 1.35 and Reynolds numbers of (2.7 – 25) × 104. For all cases, the secondary flow was found to be a single cell of circulation for each primary flow cell of a subchannel. The strength of the secondary flow increased with Reynolds number but decreased with rod spacing. The numerical results (which included friction factors, wall shear stress variations and axial velocity distributions) are shown to be in reasonable agreement with published experimental data.

Characteristics of Swirling Flow in a Circular Pipe

1994 ◽  
Vol 116 (2) ◽  
pp. 370-373 ◽  
Author(s):  
Hui Li ◽  
Yuji Tomita
Keyword(s):  
Static Pressure ◽  
Swirling Flow ◽  
Reynolds Numbers ◽  
Decay Process ◽  
Wall Pressure ◽  
Circular Pipe ◽  
Axial Position ◽  
Empirical Correlations ◽  
Pressure Distributions ◽  
Discharge Velocity

This paper examines experimentally the decay of swirl, the average dynamic, static and total pressures and the wall pressure in a pipeline 13 m in length and with an inside diameter of 80 mm for two Reynolds numbers and five different inlet swirls. The empirical correlations for the above quantities are derived, and by using these empirical correlations, the decay process and pressure distributions along the pipe for the swirling flow can be successfully computed by giving discharge velocity and a wall static pressure at any axial position.

Friction Factors for Fully Developed Turbulent Flow in Ducts With and Without Heat Transfer

1964 ◽  
Vol 86 (3) ◽  
pp. 627-636 ◽  
Author(s):  
G. W. Maurer ◽  
B. W. LeTourneau
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Circular Tube ◽  
Rectangular Channel ◽  
Reynolds Numbers ◽  
Inlet Temperature ◽  
Equivalent Diameter ◽  
Friction Factors ◽  
Rectangular Channels ◽  
Fully Developed Turbulent Flow

Tests were performed with water flowing vertically upward through a 0.087-in. × 1-in. × 27-in. long rectangular channel to determine friction factors with and without heat transfer. The following range of variables was covered: Mass velocities: 0.60 × 106 to 4.0 × 106 lbm/hr-ft2; Heat flux: 0 to 1.6 × 106 Btu/hr-ft2; Inlet temperature: 59 to 510 deg F; Pressures: 300 to 2000 psia. The isothermal data confirmed the use of the hydraulic equivalent diameter with the conventional circular tube friction factors for narrow rectangular channels at Reynolds numbers from 4 × 103 to 5 × 105. Using the results of the heated tests and the data existing in the literature, a general correlation was formulated which correlated the data for both water and air.

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