Advertisement

Experiments in Fluids

, 41:227 | Cite as

Instantaneous pressure and material acceleration measurements using a four-exposure PIV system

  • Xiaofeng Liu
  • Joseph KatzEmail author
Research Article

Abstract

This paper describes a non-intrusive technique for measuring the instantaneous spatial pressure distribution over a sample area in a flow field. A four-exposure PIV system is used for measuring the distribution of material acceleration by comparing the velocity of the same group of particles at different times and then integrating it to obtain the pressure distribution. Exposing both cameras to the same particle field at the same time and cross-correlating the images enables precision matching of the two fields of view. Application of local image deformation correction to velocity vectors measured by the two cameras reduces the error due to relative misalignment and image distortion to about 0.01 pixels in synthetic images. An omni-directional virtual boundary integration scheme is introduced to integrate the acceleration while minimizing the effect of the local random errors in acceleration. Further improvements are achieved by iterations to correct the pressure along the boundary. Typically 3–5 iterations are sufficient for reducing the incremental mean pressure change in each iteration to less than 0.1% of the dynamic pressure. Validation tests of the principles of the technique using synthetic images of rotating and stagnation point flows show that the standard deviation of the measured pressure from the exact value is about 1.0%. This system is used to measure the instantaneous pressure and acceleration distributions of a 2D cavity turbulent flow field and sample results are presented.

Keywords

Particle Image Velocimetry Pressure Distribution Shear Layer Interrogation Window Synthetic Image 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Notes

Acknowledgements

This work is sponsored by the Office of Naval Research of the United States (Program Officer Dr. Ki-Han Kim). The authors would like to thank Yury Ronzhes for the mechanical design of the testing body and Stephen King for building the timing control device. Bo Tao’s participation at the initial stage of this project and Shridhar Gopalan and Jun Chen’s valuable assistance are also gratefully acknowledged.

References

  1. Arndt REA (2002) Cavitation in vortical flows. Annu Rev Fluid Mech 34:143–175CrossRefMathSciNetGoogle Scholar
  2. Blake WK (1986) Mechanics of flow-induced sound and vibration. Academic, New YorkzbMATHGoogle Scholar
  3. Brennen CE (1995) Cavitation and bubble dynamics. Oxford University Press, OxfordGoogle Scholar
  4. Chang K-A, Liu PL-F (1998) Velocity, acceleration and vorticity under a breaking wave. Phys Fluids 10:327–329CrossRefMathSciNetGoogle Scholar
  5. Chang K-A, Cowen EA, Liu PL-F (1999) A multi-pulsed PTV technique for acceleration measurement. In: International workshop on PIV’99—Santa Barbara, 3rd, Santa Barbara, CA, USA, 16–18 September 1999, pp 451–456Google Scholar
  6. Chen J, Katz J (2005) Elimination of peak-locking error in PIV analysis using the correlation mapping method. Meas Sci Technol 16:1605–1618CrossRefGoogle Scholar
  7. Christensen KT, Adrian RJ (2002) Measurement of instantaneous Eulerian acceleration fields by particle-image velocimetry: method and accuracy. Exp Fluids 33:759–769Google Scholar
  8. Dong P, Hsu TY, Atsavapranee P, Wei T (2001) Digital particle image accelerometry. Exp Fluids 30:626–632CrossRefGoogle Scholar
  9. Girimaji SS (2000) Pressure-strain correlation modeling of complex turbulent flows. J Fluid Mech 422:91–123zbMATHCrossRefGoogle Scholar
  10. Gopalan S, Katz J (2000) Flow structure and modeling issues in the closure region of attached cavitation. Phys Fluids 12:895–911CrossRefzbMATHGoogle Scholar
  11. Gurka R, Liberzon A, Hefetz D, Rubinstein D, Shavit U (1999) Computation of pressure distribution using PIV velocity data. In: International workshop on PIV’99—Santa Barbara, 3rd, Santa Barbara, CA, USA, 16–18 September 1999, pp 671–676Google Scholar
  12. Gutmark E, Wygnanski I (1976) The planar turbulent jet. J Fluid Mech 73:465–495CrossRefGoogle Scholar
  13. Herrmann J (1980) Least-squares wave front error of minimum norm. J Opt Soc Am 70:28–35MathSciNetCrossRefGoogle Scholar
  14. Huang HT, Fiedler HE, Wang JJ (1993) Limitation and improvement of PIV, part II: particle image distortion, a novel technique. Exp Fluids 15:263–273Google Scholar
  15. Jakobsen ML, Dewhirst TP, Greated CA (1997) Particle image velocimetry for predictions of acceleration fields and force within fluid flows. Meas Sci Technol 8:1502–1516CrossRefGoogle Scholar
  16. Jensen A, Pedersen GK (2004) Optimization of acceleration measurements using PIV. Meas Sci Technol 15:2275–2283CrossRefGoogle Scholar
  17. Jensen A, Sveen JK, Grue J, Richon J-B, Gray C (2001) Accelerations in water waves by extended particle image velocimetry. Exp Fluids 30:500–510CrossRefGoogle Scholar
  18. Jensen A, Pedersen GK, Wood DJ (2003) An experimental study of wave run-up at a steep beach. J Fluid Mech 486:161–188zbMATHCrossRefGoogle Scholar
  19. La Porta A, Voth GA, Crawford AM, Alexander J, Bodenschatz E (2001) Fluid particle accelerations in fully developed turbulence. Nature 409:1017–1019CrossRefGoogle Scholar
  20. Lin JC, Rockwell D (2001) Organized oscillations of initially turbulent flow past a cavity. AIAA J 39:1139–1151Google Scholar
  21. Liu X, Katz J (2003) Measurements of pressure distribution by integrating the material acceleration. In: Cav03-GS-14-001, Fifth international symposium on cavitation (CAV2003), Osaka, Japan, 1–4 November, 2003Google Scholar
  22. Liu X, Katz J (2004) Measurements of pressure distribution in a cavity flow by integrating the material acceleration. In: HT-FED2004-56373, 2004 ASME heat transfer/fluids engineering summer conference, Charlotte, NC, USA, 11–15 July, 2004Google Scholar
  23. Liu X, Thomas FO (2004) Measurement of the turbulent kinetic energy budget of a planar wake flow in pressure gradients. Exp Fluids 37:469–482CrossRefGoogle Scholar
  24. O’Hern TJ (1990) An experimental investigation of turbulent shear flow cavitation. J Fluid Mech 215:365–391CrossRefGoogle Scholar
  25. Ooi KK, Acosta AJ (1983) The utilization of specially tailored air bubbles as static pressure sensors in a jet. J Fluids Eng 106:459–465CrossRefGoogle Scholar
  26. Ott S, Mann J (2000) An experimental investigation of the relative diffusion of particle pairs in three-dimensional turbulent flow. J Fluid Mech 422:207–223zbMATHCrossRefGoogle Scholar
  27. Pope SB (2000) Turbulent flows. Cambridge University press, CambridgezbMATHGoogle Scholar
  28. Press WH, Teukolsky SA, Vetterling WT, Flannery BP (2002) Numerical recipes in C/C++. The Press Syndicate of the University of Cambridge, CambridgeGoogle Scholar
  29. Ran B, Katz J (1994) Pressure fluctuations and their effect on cavitation inception within water jets. J Fluid Mech 262:223–263CrossRefGoogle Scholar
  30. Rockwell D, Knisely C (1979) The organized nature of flow impingement upon a corner. J Fluids Mech 93:413–432CrossRefGoogle Scholar
  31. Roth GI (1998) Developments in particle image velocimetry (PIV) and their application to the measurement of the flow structure and turbulence within a ship bow wave. PhD dissertation, Johns Hopkins UniversityGoogle Scholar
  32. Roth GI, Katz J (2001) Five techniques for increasing the speed and accuracy of PIV interrogation. Meas Sci Technol 12:238–245CrossRefGoogle Scholar
  33. Southwell WH (1980) Wave-front estimation from wave-front slope measurements. J Opt Soc Am 70:998–1006Google Scholar
  34. Sridhar G, Katz J (1995) Drag and lift forces on microscopic bubbles entrained by a vortex. Phys Fluids 7:389–399CrossRefGoogle Scholar
  35. Tang YP, Rockwell D (1983) Instantaneous pressure fields at a corner associated with vortex impingement. J Fluid Mech 126:187–204CrossRefGoogle Scholar
  36. Unal MF, Lin JC, Rockwell D (1997) Force prediction by PIV imaging: a momentum-based approach. J Fluids Struct 11:965–971CrossRefGoogle Scholar
  37. Vedula P, Yeung PK (1999) Similarity scaling of acceleration and pressure statistics in numerical simulations of isotropic turbulence. Phys Fluids 11:1208–1220CrossRefzbMATHGoogle Scholar
  38. Voth GA, Satyanarayan K, Bodenschatz E (1998) Lagrangian acceleration measurements at large Reynolds numbers. Phys Fluids 10:2268–2280CrossRefGoogle Scholar
  39. Wygnanski I, Fiedler H (1969) Some measurements in the self-preserving jet. J Fluid Mech 38:577–612CrossRefGoogle Scholar
  40. Yeung PK (2001) Lagrangian characteristics of turbulence and scalar transport in direct numerical simulations. J Fluid Mech 427:241–274zbMATHCrossRefGoogle Scholar
  41. Yeung PK (2002) Lagrangian investigations of turbulence. Annu Rev Fluid Mech 34:115–142CrossRefMathSciNetGoogle Scholar

Copyright information

© Springer-Verlag 2006

Authors and Affiliations

  1. 1.Department of Mechanical EngineeringJohns Hopkins UniversityBaltimoreUSA

Personalised recommendations