The effects of reynolds number and pressure gradient on the transitional spot in a laminar boundary layer

  • I. Wygnanski
Session III - Experiments
Part of the Lecture Notes in Physics book series (LNP, volume 136)


The flow associated with the transitional spot is discussed in view of the possible relationship between the spot and the large coherent structure existing in a fully turbulent boundary layer. A brief review of the published results is given, yet the paper stresses new data. The entrainment of non-turbulent fluid into the spot is calculated on the plane of symmetry, taking into account the growth of the spot in the direction normal to the boundary. The effects of Reynolds number on the growth of the spot is discussed, as well as some effect of favourable pressure gradient. It was observed that the spot consists of an orderly array of eddies which give rise to the streaky structure in the spanwise direction.


Boundary Layer Turbulent Boundary Layer Laminar Boundary Layer Spanwise Direction Velocity Perturbation 
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Copyright information

© Springer-Verlag 1981

Authors and Affiliations

  • I. Wygnanski
    • 1
  1. 1.School of EngineeringTel-Aviv UniversityRamat-AvivIsrael

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