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ارزیابی روش PIV در تعیین مقیاس های آشفتگی | ||
| تحقیقات مهندسی صنایع غذایی | ||
| مقاله 7، دوره 9، شماره 4، اسفند 1387، صفحه 85-102 اصل مقاله (465.12 K) | ||
| نوع مقاله: مقاله پژوهشی | ||
| نویسندگان | ||
| محمد موحدان* 1؛ میشل بلورژه2 | ||
| 1عضو هیئت علمی مؤسسه تحقیقات فنی و مهندسی کشاورزی | ||
| 2استاد دانشگاه کان فرانسه | ||
| چکیده | ||
| با توجه به پیچیدگیها و کاربردهای فراوان آشفتگی جریان، شناخت صحیح و کمّی مقیاسهای این نوع جریان در مسائل مختلف اهمیت ویژهای دارد. بهمنظور تعیین مقیاسهای آشفتگی، از روشهای آزمایشگاهی متفاوت میتوان بهره جست. اما نکتة مهم در استفاده از این روشها، صحت و دقت آنهاست. در این مقاله ابتدا ضمن بررسی روش مرسوم تیلور جهت تعیین مقیاسهای آشفتگی، روش تعیین ضرایب همبستگی با استفاده از تکنیکهای آزمایشگاهی نظیر سرعت سنج سیم داغ، سرعتسنج لیزری بررسی میشود و پس از اجرای آزمایش روی یک جریان روباز، کارایی سیستم سرعتسنجی با تصویربرداری از ذرات در تعیین مقیاسهای آشفتگی بررسی خواهد شد. نتایج این تحقیق نشان میدهد که روش ضرایب همبستگی و بهخصوص استفاده از سیستم سرعتسنجی با تصویربرداری از ذرات، به رغم محدودیتهای آن در فرکانس تصویربرداری و تفکیک پذیری دوربین و پالسهای لیزر، میتواند دسترسی به مقیاسهای آشفتگی در شرایط پیچیده را هموار سازد. | ||
| عنوان مقاله [English] | ||
| Assessment of PIV Technique on Determination of Turbulence Scales | ||
| چکیده [English] | ||
| The proper and quantitative recognition of the scale of turbulence in regard to issues such as sediment transport is of major importance. Different experimental techniques can be used to determining the scale of turbulence, but the accuracy of these techniques is open to question. In this paper, after a review of the Taylor method, the restrictions and advantages of velocity measurement techniques such as hot wire anemometry (HWA), laser doppler velocimetry (LDV) and particle image velocimetry (PIV) are described. Correlation coefficients were applied to determine the scale of turbulence using these techniques. The results showed that the main restrictions of the HWA technique were its intrusiveness and the sensitivity of the sensor. The LDV technique was restricted to measuring correlation coefficients in small distances and for just one velocity component. The results showed that the PIV technique has restrictions in its framing rate, saving image, image resolution and laser pulsing frequencies. However, considering the large spatial domain of PIV and its non-intrusive measurements and especially the continuous development of its capabilities, PIV is an appropriate technique for determination of the scale of the flow of turbulence. | ||
| کلیدواژه‌ها [English] | ||
| Correlation coefficient, Experimental Technique, Laser Doppler Velocimetry, Particle Image Velocimetry, Turbulence Scale | ||
| مراجع | ||
|
Anon. 1998. BSA Flow Software. Installation and User’s guide. DANTEC.
Anwar, H. O. and Atkins, R. 1982. Turbulent structure in an open channel flow. In: Euromech 156: Mechanics of sediment transport. Istanbul. 19-25.
Belmabrouk, H. 1992. Turbulence length scale measurements by two-point laser Doppler velocimetry. PhD Thesis. Centrale Lyon University. (in French)
Bélorgey, M., Arsié, A. and Cadiergue, S. 1999. The importance of the turbulence scale in coastal engineering. Proceedings of Hydralab Workshop. Feb. 17-19. Hanover. Germany.
Bennett, S. J. and Best, J. L. 1995. Mean flow and turbulence structure over fixed, two-dimensional dunes - implications for sediment transport and bed form stability. Sedimentlogy. 42(3): 491-513.
Bourke, P. J., Drain, L. E. and Moss, B. C. 1971. Measurement of spatial and temporal correlations of turbulence in water by laser anemometry. DISA Inf. 12, 17-20.
Cadiergue, S., Michaux - Leblond, N. and Bélorgey, M. 1999. Settling velocity of a single heavy particle in a turbulent flow. Paris Science Academy Report. Seri II b. Mech. Phys. Astron. 327(14): 1379-1384. (in French)
Cenedese, A., Romano, G. P. and Di Felice, F. 1991. Experimental testing of Taylor's hypothesis by LDA in highly turbulent flow. Experiments in Fluids. 11(6): 351-358.
Cole, J. B., Swords, M. D. and Tromans, P. S. 1980. A proposed method of measuring turbulence length scales using laser-Doppler anemometry and photon Correlation. J. Phys. D. Appl. Phys. 13, 1137-1143.
Derbunovich, G. I., Repik, E. U. and Sosedko, I. P. 1978. Experimental determination of the integral scale of turbulence in the boundary layer. Academia Nauk SSSR. Sibirskoe Otdelenie. Izvestiia. Seriia Tekhnicheskikh Nauk. (in Russian)Eriksson, J. G. and Karlsson, R. I. 1995. An investigation of resolution requirements for two-point correlation measurements using LDV. Experiments in Fluids. 18(5): 393-396.
Favre, A. J. 1965. Review on space-time correlations in turbulent fluids (Space-time correlation of turbulent flow) examining velocity and wall pressure in incompressible and compressible flow. ASME. Trans. J. appl. Mech. 32, 241-257.
Frenkiel, F. N., Klebanoff, P. S. and Huang, T. T. 1979. Grid turbulence in air and water. Phys. Fluids. 22(9): 1606-1617.
Goepfert, C., Marié, J. L. and Lance, M. 2004. Characterizing of an experimental device generating homogeneous and Isotropic turbulence by synthetic jets. The 9th French Congress of Laser Velocitymetry. ULB. Sept.14-17. Brussels. Belgium. (in French)
Hinze, J. O. 1975. Turbulence. 2nd Edition. McGraw-Hill. USA.
Hyo Jung, K., Chang, K. A. and Huang, E. T. 2005. Two-dimensional flow charataractics of wave interactions with a free-rolling rectangular structure. Ocean Eng. 32, 1-20.
Jensen, K. D. 2004. Flow Measurements. J. Braz. Soc. Mech. Sci. Eng. XXVI (4): 400-419.
LaVision. 2002. DaVis flow master software manual. Germany.
Michelet, S., Antoin, Y., Lemone, F. and Maouast, M. 1998. Direct measurement of the kinetic energy dissipation rate of turbulence using 2D LDA. Application to grid-generated turbulent flow. Paris Science Academy Report. Seri II b. Mech. Phys. Astron. 326 (10): 621-626. (in French)
Mohamed, M. S. and Larue, J. C. 1990. The decay power law in grid- generated turbulence. J. Fluid Mech. 219, 195-214.
Monin, A. S. and Yaglom, A. M. 1971. Statistical Fluid Mechanics: Mechanics of Turbulence. The MIT Press. Cambridge. Massachusetts.
Morton, J. B. and Clark, W. H. 1971. Measurements of two-point velocity. correlations in a pipe flow using laser anemometers. J. Phys. Sci. Instrum. 4, 809-814.
Movahedan, M. 2007. Analysis of the evolution of the turbulence scales in accelerated or decelerated flow: application to sediment transport. PhD Thesis. University of Caen/Basse Normandie. (in French)
Movahedan, M., Mihoubi, M. K. and Bélorgey, M. 2007. Determination of the turbulence scale using Particle Image Velocimetry. 1st International Seminar on Fluid Dynamics and Materials Processing. June. 2-5. Algiers. Algeria.
Murray, S. P. 1970. Settling velocities and vertical diffusion of particles in turbulent water. J. Geophys. Res. 75(9): 1647-1654.
Murzyn, F. 2002. Experimental study of wave influence on turbulence scales: Application to swell. PhD Thesis. University of Caen/Basse Normandie. (in French)
Murzyn, F. and Bélorgey, M. 2002. Turbulence structure in free-surface channel flows. Hydraulic Measurements and Experimental Methods Conference. July 28–August 1. Estes Park. Colorado. USA.
Murzyn, F. and Bélorgey, M. 2005. Wave influence on turbulence length scales in free surface channel flows. Exp. Thermal. Fluid Sci. 29(2): 179-187.
Nielsen, P. 1992. Coastal bottom boundary layers and sediment transport. World Scientific Pub. Advanced series on Ocean Engineering.
O’Neill, P. L., Nicolaides, D., Honnery, D. and Soria, J. 2004. Auto-correlation functions and the determination of integral length with reference to experimental and numerical data. The 15th Australasian Fluid Mechanics Conference. Dec. 13-17. Sydney. Australia.
Padet, J. P. 1990. Fluids flow. Masson. Paris. (in French)
Pope, S. B. 2000. Turbulent Flows. Cambridge Universit Press. Cambridge. UK.
Saarenrinne, P., Piirto, M. and Eloranta H. 2001. Experiences of turbulence measurement with PIV. Meas. Sci. Technol. 12, 1904–1910.
Summer, W. and Walling D. E. 2002. Modeling erosion, sediment transport and sediment yield. IHP-VI. Technical Documents in Hydrology. UNESCO. Paris.
Tennekes, H. and Lumley, J. L. 1997. A first course in turbulence. The 16th Edition. MIT Press. Cambridge. USA.
Zhou, T. and Antonia, R. A. 2000. Approximations for turbulent energy and temperature variance dissipation rates in grid turbulence. Phys. Fluids. 12(2): 335-344. | ||
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