FREE-SURFACE BOUNDARY-LAYER APPROACH TO STUDY THE BOW VORTICES GENERATION AHEAD OF A SEMISUBMERGED HORIZONTAL CIRCULAR CYLINDER

In the light of experimental observation of a free-surface shear layer. the flow ahead of a semisubmerged horizontal cylinder is modelled as a free-surface boundary layer of concentrated vorticity joining the potential flow below it with the aim to study the generation of bow vortices theoretically. The boundary-layer equations are linearized subject to a suitable assumption and are integrated using basically the Karnan Pohlhausen method. It is found that the free surface moves slower than the layer beneath it, but there is more likelihood of bow vortices being generated by instability of velocity profile rather than by separation and backflow. This is confirmed by the nonmonotonicity in the vorticity profile and the fulfilment of the Gortler instability criterion for flow along curved boundaries, near the body upstream. The position of the point of onset of instability, as stipulated from the above observations, compares well with the position of the free-surface separation point as observed in the experiments.

  • Supplemental Notes:
    • J Ship Research, v 39 n 4, Dec 1995, p 284 [13 p, 20 ref, 1 tab, 10 fig]
  • Authors:
    • Raheja, L R
  • Publication Date: 1995

Language

  • English

Subject/Index Terms

Filing Info

  • Accession Number: 00727516
  • Record Type: Publication
  • Source Agency: British Maritime Technology
  • Files: TRIS
  • Created Date: Nov 1 1996 12:00AM