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Jet into cross flow boundary layer control an innovation in gas turbine blade cooling

Javadi, K ; Sharif University of Technology | 2005

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  1. Type of Document: Article
  2. Publisher: 2005
  3. Abstract:
  4. New standpoint of turbulent coolant jets into crossflow, which have numerous applications in traditional and modern technology, especially in gas turbine blades, is presented in this work. It is more than half a century that, many researchers have been studying jet into cross flow to understand its behavior and to predict and control it better. Previous studies indicate that, the main attentions had been on: a- geometrical parameters such as: inclined and compound jet angles, hole's shape, jet's array arrangements, jet's spacing, and jet's channel depth, b- flow characteristics like: blowing ratio, density ratio, jet and cross flow Reynolds numbers, and turbulence intensity. Here, we have looked at this problem from different viewpoints and have introduced a new approach to control the jet and the cross flow interactions. In this approach, two smaller coolant jets have been installed at both sides in front of the main coolant jet. The main purposes of these two new jets are controlling the jet and the cross flow interactions and to reduce the mixing strength between them through new interactions between the counter rotating vortex pairs. Our numerical scheme was based on finite volume pressure based -SIMPLE- method using a non-uniform staggered grid. On the other hand, the Reynolds stress transport model was used to close the incompressible Reynolds averaged Navier-Stocks (RANS) equations. Our results show that, this new approach at least has four significant improvements; 1- a significant enhancement in the film cooling effectiveness (about 50%), 2- a considerable improvement in uniformity distribution of the coolant film over the plate, 3- reduction of mixing strength between the hot free stream and the coolant jets, and 4- skin friction drag reduction. Note; in order for the results of this new approach to be comparable with the ones from traditionally film cooling methods, the total coolant air and the cross sections of the new combined triple-jets have been taken to be the same as the ordinary one. © 2005 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved
  5. Keywords:
  6. Counter-rotating Vortex Pair ; Film cooling effectiveness ; Flow charac-teristics ; Gas turbine blade cooling ; Modern technologies ; Reynolds stress transport models ; Skin-friction drag ; Turbulence intensity ; Coolants ; Cooling ; Flow interactions ; Gas turbine locomotives ; Mixing ; Numerical methods ; Reynolds equation ; Reynolds number ; Gas dynamics
  7. Source: 35th AIAA Fluid Dynamics Conference and Exhibit, Toronto, ON, 6 June 2005 through 9 June 2005 ; 2005 ; 9781624100598 (ISBN)
  8. URL: https://arc.aiaa.org/doi/10.2514/6.2005-5272