Transitional Shear Layers on Rectangular Sections

  • D. M. MooreEmail author
  • C. W. Letchford
  • M. Amitay
Conference paper
Part of the Lecture Notes in Civil Engineering book series (LNCE, volume 27)


The present work implements 2D Particle Image Velocimetry measurements in an effort to study the transition process of the separated shear layer on rectangular sections. Inspection of the average and fluctuating vector fields enable quantitative definitions of important length scales such as transition lengths and reattachment lengths. The effect of free stream Reynolds number is examined in detail which, among other points, show clear trends of increasingly rapid transitions lengths over the wind speeds investigated. Additionally, transitional shear layer dynamics are discussed for sections exposed to inclined winds. It is shown that under small angles of attack, relatively large changes in shear layer trajectory result in significant alterations to the global loads felt by the body.


Bluff body Shear layer Transition Turbulence 



Portions of this work are gratefully supported through the National Science Foundation under grant number 1727401.


  1. Achenbach E (1971) Influence of surface roughness on the cross-flow around a circular cylinder. J Fluid Mech 46(2):321–335CrossRefGoogle Scholar
  2. Betchov R, Criminale WO (1966) Spatial instability of the inviscid jet and wake. Phys Fluids 9(2):359–362CrossRefGoogle Scholar
  3. Brown G, Roshko A (1974) On density effects and large structure in turbulent mixing layers. J Fluid Mech 64:775–816CrossRefGoogle Scholar
  4. Bruno L, Salvetti MV, Ricciardelli F (2014) Benchmark on the aerodynamics of a rectangular 5:1 cylinder: an overview after the first four years of activity. J Wind Eng Ind Aerodyn 126:87–106CrossRefGoogle Scholar
  5. Drazin PG (2002) Introduction to Hydrodynamic Stability. Cambridge University Press, CambridgeCrossRefGoogle Scholar
  6. Gartshore I (1973) Gartshore 1973 BLWTL report-4-73. CAN, LondonGoogle Scholar
  7. Haller G (2005) An objective definition of a vortex. J Fluid Mech 525:1–26MathSciNetCrossRefGoogle Scholar
  8. Huerre P, Monkewitz PA (1985) Absolute and convective instabilities in free shear layers. J Fluid Mech 159:151–168MathSciNetCrossRefGoogle Scholar
  9. Lander DC, Moore D, Letchford CW, Amitay M (2018) Scaling of square prism shear layers. J Fluid Mech 849:1096–1119CrossRefGoogle Scholar
  10. Mannini C, Marra AM, Pigolotti L, Bartoli G (2017) The effects of free-stream turbulence and angle of attack on the aerodynamics of a cylinder with rectangular 5:1 cross section. J Wind Eng Ind Aerodyn 161:42–58CrossRefGoogle Scholar
  11. Mannini C, Šoda A, Schewe G (2010) Computers & fluids unsteady RANS modelling of flow past a rectangular cylinder: investigation of reynolds number effects. Comput Fluids 39(9):1609–1624CrossRefGoogle Scholar
  12. Michalke A (1964) On the inviscid instability of the hyperbolic tangent velocity profile. J Fluid Mech 19(04):543–556MathSciNetCrossRefGoogle Scholar
  13. Monkewitz PA (1982) Influence of the velocity ratio n the spatial instability of mixing layers. Phys Fluids 25(7):1137–1143CrossRefGoogle Scholar
  14. Mooneghi MA, Irwin P, Chowdhury AG, Technology A, Francisco S (2015) Partial turbulence simulation method for small structures, June, pp 1–11Google Scholar
  15. Roshko A (1954) On the drag and shedding frequency of two-dimensional bluff bodies. National Advisory Committee for Aeronautics, Washington, D.C.Google Scholar
  16. Saatoff PJ, Melbourne WH (1997) Effects of free-stream turbulence on surface pressure fluctuations in a separation bubble. J Fluid Mech 337(1997):1–24CrossRefGoogle Scholar
  17. Schewe G (2013) Reynolds-number-effects in flow around a rectangular cylinder with aspect ratio 1:5. J Fluids Struct 39:15–26CrossRefGoogle Scholar
  18. Schmid P, Henningson D (2001) Stability and Transition in Shear Flows. Springer-Verlag New York Inc., USACrossRefGoogle Scholar
  19. Shimada K, Ishihara T (2001) Application of a modified k-e model to the prediction of aerodynamic characteristics of rectangular cross-section cylinders. J Fluids Struct 16(15):399–413Google Scholar
  20. Sigurdson LW (1986) The structure and control of a turbulent reattaching flow. California Institute of TechnologyGoogle Scholar
  21. Unal MF, Rockwell D (1988) On vortex formation from a cylinder. Part 1. the initial instability. J Fluid Mech 190:491–512CrossRefGoogle Scholar

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© Springer Nature Switzerland AG 2019

Authors and Affiliations

  1. 1.Department of Mechanical, Aerospace and Nuclear EngineeringRensselaer Polytechnic InstituteTroyUSA
  2. 2.Department of Civil and Environmental EngineeringRensselaer Polytechnic InstituteTroyUSA

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