1 / 44

Ivan Marusic, Nick Hutchins, Will Hambleton, Ellen Longmire, Bharath Ganapathisubramani

Analysis of multi-plane PIV measurements in a turbulent boundary layer: large scale structures, coupled and decoupled motions. Perry Fest 2004 Queen’s University, Kingston. Ivan Marusic, Nick Hutchins, Will Hambleton, Ellen Longmire, Bharath Ganapathisubramani

loki
Download Presentation

Ivan Marusic, Nick Hutchins, Will Hambleton, Ellen Longmire, Bharath Ganapathisubramani

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Analysis of multi-plane PIV measurements in a turbulent boundary layer: large scale structures, coupled and decoupled motions Perry Fest 2004 Queen’s University, Kingston Ivan Marusic, Nick Hutchins, Will Hambleton, Ellen Longmire, Bharath Ganapathisubramani Department of Aerospace Engineering and Mechanics University of Minnesota Supported by the National Science Foundation David and Lucile Packard Foundation

  2. Head & Bandyopadhyay (1981) Rq = 600 45 deg 135 deg Rq = 9400

  3. Inclined-plane stereo PIV configuration (b)   45° case 135° case

  4. In plane measured components u , v , w are transformed into streamwise, spanwise and wall-normal velocities

  5. Both inclination angles repeated at four different Reynolds numbers

  6. Comparison of mean flow parameters with data from (-) Klebanoff (1954) and (- -) Spalart (1988).

  7. Wall-parallel plane set-up

  8. Wall-parallel plane Ruu z+ = 92 Ruu z+ = 530

  9. Two-point correlation maps – all three planes stacked together Re 1100

  10. Two-point correlation maps – all three planes stacked together Re 1100

  11. Two-point correlation maps – all three planes stacked together Re 1100

  12. Two-point correlation maps – all three planes stacked together Re 1100

  13. Two-point correlation maps – all three planes stacked together Re 1100

  14. Two-point correlation maps – all three planes stacked together Re 1100

  15. Two-point correlation maps – all three planes stacked together Re 1100

  16. Two-point correlation maps – all three planes stacked together Re 1100

  17. Two-point correlation maps – all three planes stacked together Re 1100

  18. Two-point correlation maps – all three planes stacked together Re 1100

  19. Two-point correlation maps – all three planes stacked together Re 1100

  20. Two-point correlation maps – all three planes stacked together Re 1100

  21. Two-point correlation maps – all three planes stacked together Re 1100 Note: positive correlations extend further in the z direction for the 45 than for the 135 case

  22. Two-point correlation maps – all three planes stacked together Re 1100 Note: positive correlations extend further in the z direction for the 45 than for the 135 case

  23. This is due to inclined nature of the large-scale events Christensen’s two-point correlations from streamwise / wall-normal plane PIV measurements

  24. z/d= 0.5 z+= 92

  25. Decoupled Coupled

  26. Ret = 790, 1140, 2030, 3071

  27. Marusic & Perry (1995) Adrian, Meinhart & Tomkins (2000)

  28. All of the above is consistent with the scenario of packets of hairpin vortices Adrian, Meinhart & Tomkins (2000)

  29. Instantaneous wall-parallel plane data Automatedfeature-extraction algorithm Ganapathisubramani, Longmire and Marusic, JFM 2003 • z+ = 92: packets contribute 27% of <-uw>, occupy 4% of area • z+ = 150: packets contribute 24% of <-uw>, occupy 4.5% of area • NB: positive and negative uw included in %

  30. Instantaneous swirl result - 135 plane 135

  31. Instantaneous swirl result - 135 plane 135 Low-speed region

  32. Instantaneous swirl result - 135 plane 135 flanked by +ve swirls

  33. Instantaneous swirl result - 135 plane 135 and by -ve swirls

  34. Instantaneous swirl result - 135 plane 135

  35. Instantaneous swirl result - 45 plane Note: decreased occurrence of swirl over the 135 plane 45

  36. The hairpin packet model to explain the increased occurrence of swirl in the 135 plane over the 45 case.

  37. Low-speed region The hairpin packet model to explain the increased occurrence of swirl in the 135 plane over the 45 case.

  38. Comparison of RMS swirl in the 45 and 135 planes.

  39. Head & Bandyopadhyay (1981) Rq = 600 45 deg 135 deg Rq = 9400

  40. Conclusions • Inclined 45 deg. and 135 deg. PIV shows clear evidence of inclined eddies. • Two point correlation functions from multi-plane stereo PIV measurements indicate existence of long narrow coherent structures, with characteristics consistent with packets of hairpin eddies in log. region of boundary layer. • Near-wall region, including log region, is characterized by wall-coupled or attached structures, while outer wake region is characterized by decoupled structures. Consistent with notion of wall-wake eddy models.

More Related