DOI QR코드

DOI QR Code

Development of a High Resolution Digital Cinematic Particle Image Velocimetry

고해상도 Cinematic PIV의 개발

  • Published : 2001.11.01

Abstract

A high resolution digital cinematic Particle Image Velocimetry(PIV) has been developed. The system consists of a high speed CCD camera, a continuous Ar-ion laser and a computer with camera controller. To improve the spatial resolution, we adopt a Recursive Technique for velocity interrogation. At first, we obtain a velocity vector fur a larger interrogation window size based on the conventional two-frame cross-correlation PIV analysis using the FFT algorithm. Based on the knowing velocity information, more spatially resolved velocity vectors are obtained in the next iteration step with smaller interrogation windows. When the correct velocity vector at the first step is found to be critical, a Multiple Correlation Validation(MCV) technique is applied to decrease the spurious vectors. The MCV technique turns out to improve SNR(Signal to Noise Ratio) of the correlation table. The developed cinematic PIV method has been applied to the measurement of the unsteady flow characteristics of a Rushton turbine mixer. A total of 3,245 instantaneous velocity vectors were successfully obtained with 4 ms time resolution. The acquired spatial resolution corresponds to the conventional high resolution digital PIV system using a 1K ${\times}$ 1K CCD camera.

Keywords

References

  1. Lin, J.C. and Rockwell, D., 1994, 'Cinematiographic System for High-Image Density Particle Image Velocirnetry,' Exp. Fluids, Vol. 17, pp. 110-114 https://doi.org/10.1007/BF02412812
  2. 이상준, 1999, 'Cinematic PIV기법을 이용한 난류유동장 해석,' 대한기계학회 '99년도 유체공학부문 학술강연회 강연집, pp. 52-64
  3. 성재용, 유정열, 2000, 'Cinematic PIV데이터의 3차원 위상평균 기법을 이용한 실린더 후류의 2차 와류 측정,' 대한기계학회논문집 B, pp. 1540-1548
  4. Keane, R. D. and Adrian, R. J., 1990, 'Optimization of Particle Image Velocimetry,' Measurements Science and Technology, Vol, pp. 1202- 1215
  5. Hu, H., Saga, T., Kobayashi, T., Okamoto, K., and Tanig, N., 1998, 'Evaluation of the Cross Correlation Method by Using PIV Standard Images,' Journal of Visualization, Vol. 1, No. 1, pp. 87-94
  6. Hart, D. P., 1998, 'Super-Resolution PIV by Recursive Local-Correlation,' Proceedings of VSJ-SPIE 98, AB149, pp. 1-10
  7. Scarano, F., and Riethmuller, M. L., 1999, 'Iteration Multigrid Approach in PIV Image Processing with Discrete Window Offset,' Experiments in Fluids, Vol. 26, pp. 513-523 https://doi.org/10.1007/s003480050318
  8. Hu, H., Saga, T. and Kobayashi, T., 2000, 'Improve the Resolution of PIV Results by Using Hierarchical Recursive,' 9th International Symposium on Flow Visualization, pp. 1-12
  9. Okamoto, K., 1995, 'Checker Board Crosscorrelation Technique for PIV,' Proceeding of PSFVIP-2(Honolulu), CD-ROM Paper No. PF116
  10. 김형범, 이상준, 1998, '적응형 하이브리드 기법을 이용한 2-Frame PTV기법의 성능향상 연구,' 대한기계학회논문집 B, pp. 443-449
  11. Hart, D. P., 1998, 'The Elimination of Correlation Error in PIV Processing,' Proceeding of 9th International Symposium on Application of Laser of Fluid Mechanics (Lisbon)