0
Research Papers: Flows in Complex Systems

# Effect of a Triangular Rib on a Flat Plate Boundary Layer

[+] Author and Article Information

Turbulence and Energy Laboratory,
Centre for Engineering Innovation,
University of Windsor,
401 Sunset Avenue,

P. Henshaw

Turbulence and Energy Laboratory,
Centre for Engineering Innovation,
University of Windsor,
401 Sunset Avenue,
e-mail: henshaw@uwindsor.ca

D. S.-K. Ting

Mem. ASME
Turbulence and Energy Laboratory,
Centre for Engineering Innovation,
University of Windsor,
401 Sunset Avenue,
e-mail: dting@uwindsor.ca

1Corresponding author.

Contributed by the Fluids Engineering Division of ASME for publication in the JOURNAL OF FLUIDS ENGINEERING. Manuscript received February 26, 2015; final manuscript received July 23, 2015; published online August 21, 2015. Assoc. Editor: D. Keith Walters.

J. Fluids Eng 138(1), 011101 (Aug 21, 2015) (11 pages) Paper No: FE-15-1129; doi: 10.1115/1.4031161 History: Received February 26, 2015; Revised July 23, 2015

## Abstract

The flow structure downstream of a triangular rib over a thin plate placed in a wind tunnel was experimentally investigated using a boundary layer hotwire anemometer. Flow and boundary layer characteristics, such as thickness, shape, and turbulence parameters, were studied at different freestream velocities and streamwise locations corresponding to ReX of 1.7 $×$ 104–2.8 $×$ 105 for plates without and with a leading edge rib. It was found that the boundary layer of the flow over a ribbed wall was 3–3.5 times thicker and had higher turbulence intensity and smaller turbulence length scales compared to its smooth wall counterpart.

<>

## References

Saha, A. K. , and Acharya, S. , 2005, “ Unsteady RANS Simulation of Turbulent Flow and Heat Transfer in Ribbed Coolant Passages of Different Aspect Ratios,” Int. J. Heat Mass Transfer, 48(23–24), pp. 4704–4725.
Panigrahi, P. K. , and Acharya, S. , 2004, “ Multi-Modal Forcing of the Turbulent Separated Shear Flow Past a Rib,” ASME J. Fluids Eng., 126(1), pp. 22–31.
Bhagoria, J. L. , Saini, J. S. , and Solanki, S. C. , 2002, “ Heat Transfer Coefficient and Friction Factor Correlations for Rectangular Solar Air Heater Duct Having Transverse Wedge Shaped Rib Roughness on the Absorber Plate,” Renewable Energy, 25(3), pp. 341–369.
Mittal, M. K. , Varun , Saini, R. P. , and Singal, S. K. , 2007, “ Effective Efficiency of Solar Air Heaters Having Different Types of Roughness Elements on the Absorber Plate,” Energy, 32(5), pp. 739–745.
Chamoli, S. , Thakur, N. S. , and Sain, J. S. , 2012, “ A Review of Turbulence Promoters Used in Solar Thermal Systems,” Renewable Sustainable Energy Rev., 16(5), pp. 3154–3175.
Thianpong, C. , Chompookham, T. , Skullong, S. , and Promvonge, P. , 2009, “ Thermal Characterization of Turbulent Flow in a Channel With Isosceles Triangular Ribs,” Int. Commun. Heat Mass Transfer, 36(7), pp. 712–717.
Chun, S. J. , Liu, Y. Z. , and Sung, H. J. , 2004, “ Wall Pressure Fluctuations of a Turbulent Separated and Reattaching Flow Affected by an Unsteady Wake,” Exp. Fluids, 37(4), pp. 531–546.
Liu, Y. Z. , Kang, W. , and Sung, H. J. , 2005, “ Assessment of the Organization of a Turbulent Separated and Reattaching Flow by Measuring Wall Pressure Fluctuations,” Exp. Fluids, 38(4), pp. 485–493.
Panigrahi, P. K. , and Acharya, S. , 2005, “ Excited Turbulent Flow Behind a Square Rib,” J. Fluids Struct., 20(2), pp. 235–253.
Bergeles, G. , and Athanassiadis, N. , 1983, “ The Flow Past a Surface-Mounted Obstacle,” ASME J. Fluids Eng., 105(4), pp. 461–463.
Fragos, V. P. , Psychoudaki, S. P. , and Malamataris, N. A. , 2012, “ Two-Dimensional Numerical Simulation of Vortex Shedding and Flapping Motion of Turbulent Flow Around a Rib,” Comput. Fluids, 69, pp. 108–121.
Acharya, S. , and Panigrahi, P. K. , 2003, “ Analysis of Large Scale Structures in Separated Shear Layers,” Exp. Therm. Fluid Sci., 27(7), pp. 817–828.
Panigrahi, P. K. , and Acharya, S. , 1996, “ Spectral Characteristics of Separated Flow Behind a Surface-Mounted Square Rib,” AIAA Paper No. 96–1931.
Liu, Y. Z. , Ke, F. , and Sung, H. J. , 2008, “ Unsteady Separated and Reattaching Turbulent Flow Over a Two-Dimensional Square Rib,” J. Fluids Struct., 24(3), pp. 366–381.
Kamali, R. , and Binesh, A. R. , 2008, “ The Importance of Rib Shape Effects on the Local Heat Transfer and Flow Friction Characteristics of Square Ducts With Ribbed Internal Surfaces,” Int. Commun. Heat Mass Transfer, 35(8), pp. 1032–1040.
Patil, A. K. , Saini, J. S. , and Kumar, K. , 2012, “ A Comprehensive Review on Roughness Geometries and Investigation Techniques Used in Artificially Roughened Solar Air Heaters,” Int. J. Renewable Energy Res., 2(1), pp. 1–15.
Promvonge, P. , and Thianpong, C. , 2008, “ Thermal Performance Assessment of Turbulent Channel Flows Over Different Shaped Ribs,” Int. Commun. Heat Mass Transfer, 35(10), pp. 1327–1334.
Liou, T. M. , and Hwang, J. J. , 1993, “ Effect of Ridge Shapes on Turbulent Heat Transfer and Friction in a Rectangular Channel,” Int. J. Heat Mass Transfer, 36(4), pp. 931–940.
Ahn, S. W. , 2001, “ The Effects of Roughness Types on Friction Factors and Heat Transfer in Roughened Rectangular Duct,” Int. Commun. Heat Mass Transfer, 28(7), pp. 933–942.
Acharya, S. , Dutta, S. , Myrum, T. A. , and Baker, R. S. , 1994, “ Turbulent Flow Past a Surface-Mounted Two-Dimensional Rib,” ASME J. Fluids Eng., 116(2), pp. 238–246.
Hwang, R. R. , Chow, Y. C. , and Chiang, T. P. , 1999, “ Numerical Predictions of Turbulent Flow Over a Surface-Mounted Rib,” J. Eng. Mech., 125(5), pp. 497–503.
Antoniou, J. , and Bergeles, G. , 1988, “ Development of the Reattachment Flow Behind Surface-Mounted Two-Dimensional Prisms,” ASME J. Fluids Eng., 110(2), pp. 127–133.
Acharya, S. , Myrum, T. A. , and Dutta, S. , 1998, “ Heat Transfer in Turbulent Flow Past a Surface-Mounted Two-Dimensional Rib,” ASME J. Heat Transfer, 120(3), pp. 724–734.
Incropera, F. P. , and DeWitt, D. P. , 1996, Fundamentals of Heat and Mass Transfer, 3rd ed., Wiley, New York.
Jørgensen, F. E. , 2002, How to Measure Turbulence With Hot-Wire Anemometers: A Practical Guide, Dantec Dynamics, Skovlunde, Denmark.
Figliola, R. S. , and Beasley, D. E. , 2011, Theory and Design for Mechanical Measurements, 5th ed., Wiley, New York.
Tariq, A. , Panigrahi, P. K. , and Muralidhar, K. , 2004, “ Flow and Heat Transfer in the Wake of a Surface-Mounted Rib With a Slit,” Exp. Fluids, 37(5), pp. 701–719.
Clauser, F. H. , 1956, “ Turbulent Boundary Layer,” Adv. Appl. Mech., 4, pp. 1–51.
Shin, J. H. , and Song., S. J. , 2015, “ Pressure Gradient Effects on Smooth-and Rough-Surface Turbulent Boundary Layers—Part I: Favorable Pressure Gradient,” ASME J. Fluids Eng., 137(1), p. 011203.
Shin, J. H. , and Song., S. J. , 2015, “ Pressure Gradient Effects on Smooth-and Rough-Surface Turbulent Boundary Layers—Part II: Adverse Pressure Gradient,” ASME J. Fluids Eng., 137(1), p. 011204.
Antonia, R. A. , and Luxton, R. E. , 1972, “ The Response of a Turbulent Boundary Layer to a Step Change in Surface Roughness—Part 2: Rough-to-Smooth,” J. Fluid Mech., 53(4), pp. 737–757.
DeGraaff, D. B. , and Eaton, J. K. , 2000, “ Reynolds-Number Scaling of the Flat-Plate Turbulent Boundary Layer,” J. Fluid Mech., 422, pp. 319–346.
Hancock, P. E. , and Bradshaw, P. , 1983, “ The Effect of Free-Stream Turbulence on Turbulent Boundary Layer,” ASME J. Fluids Eng., 105(3), pp. 284–289.
Sucec, J. , 2014, “ An Integral Solution for Skin Friction in Turbulent Flow Over Aerodynamically Rough Surfaces With an Arbitrary Pressure Gradient,” ASME J. Fluids Eng., 136(8), p. 081103.
Saturdi , and Ching, C. Y. , 1999, “ Effect of a Transverse Square Groove on a Turbulent Boundary Layer,” Exp. Therm. Fluid Sci., 20(1), pp. 1–10.
Barrett, M. J. , and Hollingsworth, D. K. , 2001, “ On the Calculation of Length Scales for Turbulent Heat Transfer Correlation,” ASME J. Heat Transfer, 123(5), pp. 878–883.
Carullo, J. S. , Nasir, S. , Cress, R. D. , Ng, W. F. , Thole, K. A. , Zhang, L. J. , and Moon, H. K. , 2011, “ The Effects of Freestream Turbulence, Turbulence Length Scale, and Exit Reynolds Number on Turbine Blade Heat Transfer in a Transonic Cascade,” ASME J. Turbomach., 133(1), p. 011030.
Sak, C. , Liu, R. , Ting, D. S.-K. , and Rankin, G. W. , 2007, “ The Role of Turbulence Length Scale and Turbulence Intensity on Forced Convection From a Heated Horizontal Circular Cylinder,” Exp. Therm. Fluid Sci., 31(4), pp. 279–289.
Hinze, J. O. , 1975, Turbulence, 2nd ed., McGraw-Hill, New York.
Taylor, G. I. , 1938, “ The Spectrum of Turbulence,” Proc. R. Soc. London, Ser. A, 164(919), pp. 476–490.
Dennis, D. J. C. , and Nickels, T. B. , 2008, “ On the Limitations of Taylor's Hypothesis in Constructing Long Structures in a Turbulent Boundary Layer,” J. Fluid Mech., 614, pp. 197–206.
Lin, C. C. , 1953, “ On Taylor's Hypothesis and the Acceleration Terms in the Navier–Stokes Equation,” Q. Appl. Math., 10(4), pp. 295–306.
Lumley, J. L. , 1965, “ Interpretation of Time Spectra Measured in High-Intensity Shear Flows,” Phys. Fluids, 8(6), pp. 1056–1062.
Builtjes, P. J. H. , 1975, “ Determination of the Eulerian Longitudinal Integral Length Scale in a Turbulent Boundary Layer,” Appl. Sci. Res., 31(5), pp. 397–399.

## Figures

Fig. 1

Rib mounted flat plate schematic

Fig. 2

Test section side view

Fig. 3

Velocity profiles for smooth and ribbed wall at (a) U = 4 m/s, (b) U = 6.8 m/s, and (c) U = 9 m/s

Fig. 8

Wake parameter at U = 9 m/s

Fig. 7

Turbulent boundary layer normalized velocity profile of DeGraaff and Eaton [32]

Fig. 6

Normalized velocity profiles inside the boundary layer at U = 9 m/s for the (a) smooth and (b) ribbed wall

Fig. 5

Liu et al. [14] velocity profile over a square-ribbed surface

Fig. 4

Flow over a (a) square-ribbed surface [14] and (b) wedge-ribbed surface [3]

Fig. 9

Turbulence intensity profiles for smooth and ribbed wall at (a) U = 4 m/s, (b) U = 6.8 m/s, and (c) U = 9 m/s

Fig. 10

Wall-normal location of maximum streamwise Tu: (a) present study at U = 9 m/s and (b) Liu et al. [14]

Fig. 11

FFT of velocity fluctuation signal at Y/H = 1

Fig. 12

Autocorrelation coefficient for ribbed wall at X/H = 20, Y/H = 2.2, and U = 9 m/s, the dashed line shows the parabola fitted curve to the first five points of R(τ)

Fig. 13

Ribbed wall integral length scale at U = 9 m/s

Fig. 14

Ribbed wall integral length scale at (a) U = 4 m/s, (b) U = 6.8 m/s, and (c) U = 9 m/s

Fig. 15

Taylor microscale in the boundary layer at U = 9 m/s

## Errata

Some tools below are only available to our subscribers or users with an online account.

### Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related Proceedings Articles
Related eBook Content
Topic Collections