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بررسی تجربی اثر آشفتگی جریان ورودی بر میدان فشار ناپایا و نویز جریان پیرامون استوانه دایره‌ای | ||
| نشریه مهندسی مکانیک امیرکبیر | ||
| مقاله 12، دوره 52، شماره 4، تیر 1399، صفحه 923-942 اصل مقاله (3.3 M) | ||
| نوع مقاله: مقاله پژوهشی | ||
| شناسه دیجیتال (DOI): 10.22060/mej.2018.13842.5727 | ||
| نویسندگان | ||
| رضا مریمی1؛ علی اکبر دهقان* 2؛ عباس افشاری3 | ||
| 1گروه مکانیک، دانشکده مهندسی مکانیک، دانشگاه یزد، ایران | ||
| 2هیلت علمی-دانشگاه یزد | ||
| 3دانشجوی دکترا/ دانشگاه یزد | ||
| چکیده | ||
| میدان فشار ناپایا روی سطح استوانه‌ای با مقطع دایره‌ای، به عنوان منشأ اصلی نویز ثبت شده در دوردست، دارای رفتار فیزیکی پیچیده‌ای بوده که تاکنون مطالعات مختصری روی آن و مخصوصا در جریان آزاد آشفته انجام گرفته است. بنابراین در مطالعه حاضر نوسانات فشار ناپایا روی سطح استوانه‌ای با قطر خارجیmm 22 تحت شرایط جریان آزاد آرام و آشفته به طور تجربی بررسی شده است. تغییر شرایط آشفتگی جریان آزاد با استفاده از شبکه‌هایی با مش‌های مربعی مختلف انجام شده است. به منظور فهم دقیق رفتار نویز جریان پیرامون مدل، پارامترهایی نظیر طیف فشار سطح، تابع همدوسی، همبستگی خودکار و متقابل، طول مشخصه ساختارهای گردابه‌ای در دهانه مدل و همچنین سرعت جابه‌جایی این ساختارها در راستای جریان با استفاده از نوسانات فشار سطح محاسبه شده است. نتایج نشان دادند که تغییر ماهیت جریان آزاد از آرام به آشفته سبب افزایش سطح انرژی نویز باریک باند و پهن باند می‌شود. علاوه بر این فرکانس نویز به سمت ( f = 98Hz ) در مقایسه با مقدار متناظر در جریان آزاد آرام( f ' = 88Hz ) باریک باند در جریان آزاد آشفته فرکانس‌های پایین جابجا می‌گردد. دیگر نتایج نشان دادند که اندازه گردابه‌ها و سرعت جابه‌جایی این ساختارها در جریان آزاد آرام بزر گتر از جریان آزاد آشفته است. | ||
| کلیدواژه‌ها | ||
| نوسانات فشار سطح؛ شبکه‌های تولید کننده جریان آشفته؛ نویز باریک باند؛ فرکانس ریزش گردابه | ||
| عنوان مقاله [English] | ||
| Experimental investigation of the turbulence effect of incoming flow on the unsteady pressure field and the flow noise around circular cylinder | ||
| نویسندگان [English] | ||
| Reza Maryami1؛ Ali Akbar Dehghan2؛ abbas afshari3 | ||
| 1Mech. Eng. Dept, Factulty of Engineering, Yazd University, IRAN | ||
| 2Mech. Eng. Dept, Faculty of Engineering, Yazd University, IRAN | ||
| 3phd student / yazd university | ||
| چکیده [English] | ||
| Surface pressure fluctuations on a circular cylinder model are the main sources of far- field noise emitted and have complex physical behavior. So far, limited studies have been devoted to identifying the unsteady surface pressure behavior, especially for turbulence incident flow. In the present study to measure the surface pressure fluctuations under both smooth and turbulence incoming flows, a circular cylinder with an outer diameter of 22mm has been used. In order to change the turbulence characteristics of free stream incoming flow, different biplane grids with square meshes were designed. Power spectral density, coherence, autocorrelation and cross-correlation, spanwise length scale, and convection velocity were different interesting parameters which were calculated using measured unsteady pressures in order to better clarify the flow structure and flow noise around the model. The results revealed that the energy level of both tonal and broadband noises is increased when incident flow changes from smooth to turbulent. Moreover, the tonal noise frequency in the turbulence flow ( f ' = 88 Hz ) shifts to low frequencies compared to that of smooth flow ( f = 98 Hz ). Furthermore, results showed that the physical size of eddies and their convection velocity in turbulence flow are greater than corresponding values for smooth flow. | ||
| کلیدواژه‌ها [English] | ||
| Surface pressure fluctuations, Turbulence generation grids, Tonal noise, Vortex shedding frequency | ||
| مراجع | ||
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[1] Strouhal, V., “Ueber eine besondere art der tonenegung”, Annalen der Physik und Chemie (Leipzig) Series 3. 5. (1878): pp. 216-251. [2] Rayleigh, L., “Acoustical observations II”, Philosophical Magazine. 7.( 1879): pp. 149-162. [3] Bernard, H., “Formation des centres de giration a I’arriere d’un obstacle en mouvement”, Compte rendu hebdomuduire des seances de l’Academie des Sciences, Paris 147. (1908): pp. 839-842. [4] Karman, T. V., Rubach, H., “Uber den mechanismus des flussigkeits- und luftwiderstandes”, Physikufische Zeitschrifi, 13. (1912): pp. 49-59. [5] Kruger, F. V., Lauth, A., “Theorie der hiebtone”. Annulen der Physik (Leipzig), 44, (1914): pp. 801- 812. [6] Borne, R. D., As quoted in reference[9], Zeitschrift Hugtechnik. Vol.3, 30. [7] Rayleigh, L., “Aeolian tones”. Philosophical Magazine. 29, (1915): pp. 434-444. [8] Relf, E. F., “On the sound emitted by wires of circular section when exposed to an air current”. Philosophical Magazine. 42. (1921): pp. 173-176. [9] Richardson, E. G., “Aeolian tones”, Proceedings of the Physical Society of London, .36. (1923-1924):153-157. [10] Davis, M. R., Pan, N. H., “Noise generation by the interaction of turbulent jets with circular cylinder”, Journal sound and vibration, 3. (1989): pp. 427-442. [11] Hutcheson, F. V., Brooks, T.F., “Noise radiation from single and multiple rod configurations”. International Journal of Aeroacoustics, 11(3&4).)(012):291–334. [12] Pillips, O. M., “The intensity of Aeolian tone, Journal of fluid mechanics, 1. (1956): pp. 607. [13] Blake, W. K. “Mechanics of flow-induced sound and vibration”. General Concepts and Elementary Sources, 1. (1986.): pp. 44–64. [14] Curle, N., “The influence of solid boundaries upon aerodynamic sound”, Proceedings of the Royal Society of London Series A, 231. (1955): pp. 505– 51. [15] Afshari, A., Dehghan, A. A., Kalantar, V., Farmani, M.. “Experimental investigation of surface pressure spectra beneath turbulent boundary layer over a flat plate with microphone”, Modares Mechanical Engineering, 17. 1. (2017): pp. 263-272, (in Persian). [16] Williams, J. F., Hall, L., “Aerodynamic sound generation by turbulent flow in the vicinity of a scattering half plane”. Journal of Fluid Mechanics, 40. (1970): pp. 657-670. [17] Fujita, H., Suzuki, H., “The Aeolian tone and the surface pressure in high Reynolds number flow”. AIAA paer. 99-(2002 ). [18] Casalino, D., Jacob, M., “Prediction of aerodynamic sound from circular rods via spanwise statistical modeling”. Journal of Sound and Vibration. 262.(2003): pp. 815–844. [19] Maryami, R., Dehghan, A. A., Afshari, A., “Experimental investigation of circular cylinder model noise by measuring unsteady surface pressures”, Amirkabir Journal of Mechanical Engineering, Accepted Manuscript, (2017). [20] Fujita, H., “The characteristics of the Aeolian tone radiated from two-dimensional cylinders”. Fluid Dynamics Research, 42. (2010):1–25. [21] Leclercq, D., Doolan, C.J., “The interaction of a bluff body with a vortex wake”. Journal of Fluids and Structures, 25. (2009): 867–888. [22] Ackerman, J. R., Gostelow, J. P., Rona, A., Carscallen, W. E., “Measurements of Fluctuating Pressures on a Circular Cylinder in Subsonic Cross flow” AIAA JOURNAL, 47 (2009): 2121-2131. [23] Oguma, Y., Yamagata, T., Fujisawa, N., “Measurement of sound source distribution around a circular cylinder in a uniform flow by combined particle image velocimetry and microphone technique” J. Wind Eng. Ind. Aerodyn.118, (2013):1–11. [24]Doolan, C.J., “Computation bluff body aerodynamic noise prediction using a statistical approach”. Applied Acoustics, 71(2010):1194–1203. [25] Ali, M.S.M., Doolan, C.J., Wheatley,V., “Aeolian tones generated by a square cylinder with a detached flat plate”. AIAAJournal, 51 (2013): 291–301. [26] Orselli, R. M., Meneghini, J. R., and Saltara, F., “Two and Three-Dimensional Simulation of Sound Generated by Flow Around a Circular Cylinder” 15th AIAA/CEAS Aeroacoustics Conference )30th AIAA Aeroacoustics Conference( 11 - 13 May (2009), Miami, Florida. [27] Barlow, J. B., Rae, W., Pope, A., “Low-speed wind tunnel testing”, John Wiely & Sons, Inc, (1999). [28] Wilkins, S. J., Hall, J. W., “Experimental Investigation of a Tandem Cylinder System With a Yawed Upstream Cylinder”, Journal of Pressure Vessel Technology. 136. (2014): pp. 1-8. [29] Hutcheson, F. V., Brooks, T. F., Lockard, D. P., Choudhari, M. M., Stead. D. J., “Acoustics and Surface Pressure Measurements from Tandem Cylinder Configurations”, 20th AIAA/CEAS Aeroacoustics Conference, AIAA AVIATION Forum, (AIAA 2014-2762). [30] Salze, É., Bailly, C., Marsden, O., Jondeau, E., Juvé, D., “An experimental characterization of wall pressure wave vector-frequency spectra in the presence of pressure gradients”, in Proceeding of, (2014). [31] Uberoi, M. S., Wallis, S., “Effect of Grid Geometry on Turbulence Decay”, Phys. Fluids, 9. (1967): pp. 1216-1224. [32] Corrsin, S., “Turbulence: experimental methods”. In Handbuch der Physik (ed. S. Flugge & C.A. Truesdell), pp. 524-589. [33] Roach, P.E., “The generation of nearly isotropic turbulence by means of grids”, Int J Heat Fluid Flow, 8. (1963): pp. 82–92. [34] Lavoie, P., Djenidi, L. Antonia, R. A., “Effect of Initial Conditions on the Generation of Coherent Structures in Grid Turbulence”, Book of Extended Abstracts Whither Turbulence Prediction and Control, Seoul, Korea, (2006). [35] Aufderheide, T., Bode, C., Kozulovic, D., Friedrichs, J., “The generation of higher levels of turbulence in a low-speed cascade wind tunnel by pressurized tubes”, 11th World Congress on Computational Mechanics (WCCM XI). [36] Laws, E. M., Livsey, J. L., “Flow through screens”, Ann. Rev. Fluid Mech. 10, (1978): pp.247-266. [37] Mohamed, M. S., Larue, J. C., “The decay power law in grid-generated turbulence”, J. Fluid Mech. 219. (1990): pp. 195-214. [38] Hinze, J., Turbulence, 2nd Ed., McGraw-Hill, New York, (1975). [39] Bendat, J. S., Piersol, A. G., “Random data: analysis and measurement procedures”, John Wiley & Sons, (2011). [40] Sagrado, A. G., “Boundary Layer and Trailing Edge Noise Sources”, Ph.D. Thesis, Department of Engineering, University of Cambridge, (2007). [41] Herrig, A., Kamruzzaman, M., Würz, W., Wagner, S., “Broadband airfoil trailing-edge noise prediction from measured surface pressures and spanwise length scales, noise notes”, 12. (2013): pp.13-36. [42] Achenbach, E., “Distribution of local pressure and skin friction around a circular cylinder in cross- flow up to Re = 5×106”, J. Fluid Mech. 34. (1968): PP.625-639. [43] Sadeh, W., Saharon, D.B., “Turbulence Effect On Cross flow Around a Circular Cylinder at Subcritical Reynolds Numbers”, NASA Contractor Report 3622. [44] Norberg, C., “Interaction between free stream turbulence and vortex shedding for a single tube in cross flow”, Journal of Wind Engineering and Industrial Aerodynamics, 23. (1986): pp. 501-514. [45] Norberg, C., “Effect of Reynolds number and a low-intensity free stream turbulence on the flow around a circular cylinder”, Ph.D. Thesis, Chalmers university of technology, (1987). [46] Breuer, M., “Large eddy simulation of the subcritical flow past a circular cylinder: Numerical and modeling aspects”, Int. J. Numer. Meth. Fluids, 28. (1998): pp. 1281–1302. [47] Jenkins, L.N., Khorrami, M.R., Choudhari, M.M., McGinley, C.B., “Characterization of Unsteady Flow Structures Around Tandem Cylinders for Component Interaction Studies in Airframe Noise”, AIAA paper. AIAA-2005-2812, May 2005. | ||
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