Identification of self-organized vortexlike structures in numerically simulated turbulent flow of a viscous incompressible liquid streaming around a well on a plane

Effect of rounded edged dimple arrays on the boundary layer development

“…Other methods besides single point measurements, such as flow visualization may be required to identify the shedding and determine its range of frequencies. Isaev et al (2000Isaev et al ( , 2003 observed similar flow patterns in their computational studies of sharp and rounded edged dimples. The secondary flow in the upstream half of the dimple is actually observed to flow with an upstream component both by Ligrani et al (2001) and Isaev et al (2000Isaev et al ( , 2003.…”

“…Isaev et al (2000Isaev et al ( , 2003 observed similar flow patterns in their computational studies of sharp and rounded edged dimples. The secondary flow in the upstream half of the dimple is actually observed to flow with an upstream component both by Ligrani et al (2001) and Isaev et al (2000Isaev et al ( , 2003. This phenomenon of upstream flow is similarly observed in the present study (labeled 'G G' in Fig.…”

“…Since the shedding or ejection of fluid is a key feature of the flow over dimples Ligrani et al, 2001 andLigrani, 2000;Mahmood and Ligrani, 2002;Park et al, 2004), the streamwise velocity field immediately downstream of the dimples is measured in an attempt to study this phenomenon. This shedding arises from the flow separating away from the surface over the upstream dimple edge (Isaev et al, 2000).…”

“…Early investigations of the effects of dimple cavities have focused mainly on the changes in the flow structures or heat transfer either inside or downstream of a single or multiple dimples on a channel wall Isaev et al, 2000;Ligrani et al, 2001 andLigrani, 2000;Mahmood and Ligrani, 2002). These favorable heat transfer effects have led to the proposed use of dimpled surfaces ranging from micro-scale passages for electronics cooling devices to cooling passages in large-scale turbine airfoils used for electrical power generation .…”

“…Computational studies of the flow over an isolated dimple by Isaev et al (2000) reveals a complex vortex forming in the dimple due to the flow separating at the edge of the dimple. Ligrani et al (2001) reported instantaneous flow patterns obtained experimentally over a dimple array consisting of 13 staggered rows of dimples in a rectangular channel.…”