1. Air filmcooling through laser drilled nozzles STW project CASA-dag 09.05.2006

2. Outline of the presentation 1.Introduction 2.Current situation 3.Local Uniform Grid Refinement 4.Boundary conditions 5.Conclusions and future plans

3. Introduction

6. Film cooling holes can be drilled by electro-discharged drilling laser drilling

7. Laser drilling is a fast but crude process Cooling effectivity depends on detailed flow-’structure’

8. Problem of interest

9. Apparatus and Measurements Techniques The water channel with the glass test section (2.00 x 0.57 x 0.45 m) The interaction of the cross flow and the inclined jet over the flat plate Measurements technique  Particle Image Velocimetry – PIV  Laser Induced Fluorescence - LIF Visualization  Liquide Crystal Thermography - LCT Water channel at the TU/e

10. The water channel and the set-up for the inclined jet α = 35 0 U  = 0.20m/s U jet is adjusable

11. Coherent Structures in a Jet Crossflow Interaction

12. Vertical laser sheet

13. Averaged velocity in the inner-torus case VR=0.45

14. Current situation Compressible Navier-Stokes DNS code Parallel Fortran code for Silicon Graphics and Beowulf Cluster

15. Problem Need more resolution in high activity area Answer (simple) Buy bigger computer Answer (smart) Local grid refinement

16. two grid LUGR algorithm Smart answer - two grid LUGR algorithm

17. LUGR algorithm GlobalcoarseGridGlobalcoarseGrid LocalfineGridLocalfineGrid Boundary conditions Substitution

18. Dirichlet BC from the coarse grid Using “physical” variables (velocity, pressure, etc.) Using “acoustical” quantities (directions and amplitudes of the incoming and outgoing waves) Boundary conditions for the fine grid

19. Results of calculation

20. Composite grid Equivalent uniform fine grid Results of calculation

21. Computation time

22. Results of computation

23. Real: ? Simple: Parabolic linear Boundary conditions – jet profile

24. Boundary conditions at walls Velocity and temperature profile at nozzle’s exit DNS code Unstructured solver Boundary conditions – jet profile

25. Imperfections

27. Horizontal (x) velocity

28. Vertical (y) velocity

29. Some results

30. 1.All three velocity components are present 2.Profiles differ from parabolic, specially for inaccuracies close to the exit 3.Qualitative agreement between experimental and numerical results Summary

31. 1.Size – “blockage” 2.Position – better have inaccuracies away from the exit 3.Shape – “small” influence Boundary conditions – some conclusions

32. Conclusions 1.Local grid refinement. 2.First results for inflow profiles. Different imperfections Influence of size, shape, position

33. Future plans (next 1.5 months) 1.Back substitution of inflow profiles. 2.Comparison of the heat fluxes with experiments.

34. Questions?