THERMAL SCIENCE

International Scientific Journal

Thermal Science - Online First

online first only

Turbulence investigation in the VTI’s experimental aerodynamics laboratory

ABSTRACT
Wind tunnels are the aerodynamic laboratories which task is to enable high quality and stabile air flow in controlled volume, a test section, during run time, in order to study the effects of streaming around various aeronautical or non-aeronautical models (airfoils and bluff bodies with complex motorized or robotic constructions). The main requirement that leads to quality and reliable measurement results is a high flow quality in the test section: uniformity of the velocity and pressure fields along and across the test section, low turbulence level and low flow direction angularities or swirling. The knowledge of low parameters enables the exchange of the scientific and technical information, comparison of the experimental results from different wind tunnels and data scaling of the model to the real scale. The turbulence intensity TI significantly affects the wind tunnel results and reduction of turbulence is of the highest importance for the quality measurements. This paper presents the Experimental Aerodynamics Laboratory of the VTI in Belgrade, the equipment and methods of turbulence measurements in the test section stream and around different test models. Wind tunnel facilities maintain equipment and devices for sampling, acquisition and data reduction for various test types, from forces and moment measurements, over the pressure distribution measurements to the advanced measurements, followed with the appropriate flow visualization techniques. The modern instrumentation enables determine flow quality and its influence on tests and measurement results of static and dynamic model characteristics.
KEYWORDS
PAPER SUBMITTED: 2016-01-30
PAPER REVISED: 2016-06-29
PAPER ACCEPTED: 2016-06-29
PUBLISHED ONLINE: 2016-08-07
DOI REFERENCE: https://doi.org/10.2298/TSCI160130187R
REFERENCES
  1. Harvey, W.D., et al., An evaluation and assessment of flow quality in selected NASA wind tunnels, NASA Techni-cal Memorandum 85659, 1983.
  2. Sisojev, V., Estimation of Losses for the Wind Tunnels (in Serbian), VTI, Belgrade, Serbia, VS-125, 1956.
  3. Owen, F.K., et al., An Evaluation of Factors Affecting the Flow Quality in Wind Tunnels, AGARD, Conference Paper, February 1984.
  4. Steinle, F., Stanewsky, E.,Wind Tunnel Flow Quality and Data Accuracy Requirements, AGARD Advisory report No. 184, ISBN 92-835-1440-8, November 1982.
  5. Loehrke, R.I., Nagib, H.M., Experiments on Management of Free-Stream Turbulence, AGARD Report No. 598, Sep-tember 1972.
  6. Chang, P.K., Control of Flow Separation, Hemisphere, Washington, D.C. 1976.
  7. Schlichting, H., Boundary-Layer Theory, 7th edn., McGraw-Hill, New York, 1979.
  8. Achenbach, E., The Effects of Surface Roughness and Tunnel Blockage on the Flow Past Spheres, Journal of Fluid Mechanics, (1974), 65, pp 113-125.
  9. Mrkalj, N., About Selection of Basic Characteristics of a Wind Tunnel T-35 (in Serbian), VTI, VS-116., 1955.
  10. Zotović, S., Selection of Low-Speed Wind Tunnel Type (in Serbian), VTI, VS-002.
  11. Šumonja, S., EA Training: A Low-Speed Wind Tunnel Theory and Design, VTI, 1997.
  12. Sisojev, V., Calculation of Collectors, (in Serbian), University of Belgrade, 1948.
  13. Pope, A., Wind Tunnel Calibration Techniques, AGARDograph 54, AGARD, 1964.
  14. Linić, S., et al., Experimental and Numerical Study of Super-Critical Flow Around the Rough Sphere, Scientific Technical Review, 65 (2015), 2, pp.11-19.
  15. Reed, T.D., et al., Calibration of Transonic and Supersonic Wind Tunnels, NASA Contractor Report 2920, NASA, 1977.
  16. Ocokoljić, G., et al., Testing of a Standard Model in the VTI's Large-subsonic Wind-tunnel Facility to Establish Users' Confidence, FME Transactions (2014), 42, pp.212-218
  17. Šumonja, S., EA Training: Low Speed Wind Tunnel Testing, VTI, 1997.
  18. Šumonja, S., Testing of a Motorized Model in Subsonic Wind Tunnel (in Serbian) Scientific Technical Review, 48 (1998), 5, pp50-63.
  19. Mrkalj, N., Šumonja, S., Testing of the Model with Inlet at the Wind Tunnel T-32 (in Serbian) Scientific Technical Review, 46 (1996), 4-5, pp. 51-59.
  20. Mrkalj, N. Šumonja, S., Uređaj za merenje protoka vazduha u ulaznom preseku kompresora motora vazduhoplova (in Serbian), Scientific Technical Review, 49 (1999), 5, pp.63-68.
  21. Ćurčin, M., Šumonja, S., Određivanje ravnoteže kružne frekvencije obrtanja turbinskog kola anemometra (in Ser-bian) Scientific Technical Review, 45 (1995), 4-5, pp. 3-8.
  22. Samardžić, M., et al., The sting plunging effect on measured pitch damping derivative, Proceed. of 6th international scientific conference, OTEH 2014., (2014), Belgrade
  23. Ćurčić, D., et al., Model sting support with hard metal core for measurement in the blowdown pressurized wind tunnel, Measurement, 79 (2016), pp. 130-136
  24. Samardžić, M., et al., Effects of the Sting Oscillation on the Measurements of Dynamic Stability Derivatives, Sci-entific Technical Review, 60 (2010), 2, pp.22-26
  25. Samardžić, M., et al., The sting plunging effect on measured pitch damping derivative, Proceed. of 6th international scientific conference, OTEH 2014., (2014), Belgrade
  26. Anastasijevic, Z., Ristic, S., Prikaz mogučnosti ispitivanja u laboratorijama eksperimentalne aerodinamike (in Ser-bian), Tehnika, Mašinstvo, 55 (2006), pp.15-24.
  27. Vitić, A., Estimation of the Free Flow Turbulence intensity at Wind Tunnel T-35, in a velocity range from 0.2
  28. Ristić, S., Laser Doppler Anemometry and its Application in Wind Tunnel Tests, Scientific Technical Review, 57 (2007), 3-4, pp.64-76.
  29. Ristić, S., et al., Laser Doppler Anemometry Application in Hydrodynamic Testing, Atti dela Fondazione Giorgio Ronchi, 62 (2007), pp. 207-218.
  30. Ristić, S., Ilić, J., Laser Doppler anemometrijska merenja u cevima različitog oblika i kvaliteta stakala, Scientific Technical Review, 49 (1999), 5, pp.22-29.
  31. Ilić, J. T., et al., The Comparison of Air Flow LDA Measurement in Simple Cylindical and Cylindrical Tube with Flat External Wall, FME Transactions, 41, (2013), pp. 333-341
  32. Watrasiewich, B.M. Laser Doppler Measurement, Butterworths, London, 1976.
  33. Hunter, W.W., Flow Visualization and Laser Velocimetry for wind tunnel, NASA Conference Publication 2243, (1982)
  34. Ristić, S., Analysis of the Accuracy of the Third Component of Flow Velocity Measurements for a 3-component, 3-colour Laser Doppler Anemometer., Proc. of Inter. conference on Laser 97, (1997), New Orleans, Louisiana, pp. 562-569
  35. Ristić, S., Majstorović P., Eksperimentalno ispitivanje relativnog strujanja kroz model prave profilne rešetke, Scien-tific Technical Review, 50, (2000), 6, pp. 29-36.
  36. Ristić, S., et al., Eksperimentalno i numeričko određivanje Sr hidroprofila u stacionarnom i nestacionarnom stru-janju, 30, Proc. of HIPNEF 2006, Vrnjačka Banja, pp.541-548.
  37. Ristic, S., et al., Determination of Air and Hydrofoil Cp by Laser Doppler Anemometry, Theoret. Appl. Mech., 37 (2010), 1, pp. 17-35,
  38. Srećković, M., et al., The Analysis of Characteristic Materials for Fluid Seeding Particles in Wind Tunnels and Their influence on the LDA System Functions, Balkan Physics Letters, 7, (2), 1999, pp. 93-102 .
  39. Ristić, S., Laser Doppler Anemometry and its Application in Wind Tunnel Tests, Scientific Technical Review,57 (2007), 3-4,pp. 64-76.
  40. Jovanović, B., et al., Faktor turbulrncije T-31, V3-138, 1957, str. 1-39.
  41. Vujić, V., et al., Iznalaženje metoda za merenje turbulencije, V3-796, 1968, str. 1-15
  42. Ristić, S., Flow visualization techniques in wind tunnels, Part I-Non optical Methods, Scientific Technical Review, 57 (2007), 1,pp.39-50.
  43. Ristić, S., Flow visualization techniques in wind tunnels, Part II-Optical Methods, Scientific Technical Review, 57 (2007), 2; pp.48-49.
  44. Marzkirich,W., Flow visualization, Academic Press, New York, 1977.
  45. Settles, G.S., Modern Developments in Flow Visualization, AIAA Journal, 24 (1986),8, pp.1313-1323
  46. Ristić, S., Capability of two-dimensional Reynolds-averaged Navier-Stokes simulations for two-dimensional thrust vectoring nozzles, Proc.of Institute of Mech. Part G: J. Aerospace Engineering G, 224, (2010) G8, pp 905-910.
  47. Puharić, M., et al., Laser Doppler Anemometry in Hydrodynamic Testing, Journal of Russian Laser Research, 28 (2007), 6, pp.619-628.
  48. Ristić, S., Investigation of Supersonic Flow in Wind Tunnel T-38 by a Method of Holographic Interferometry, Sci-entific Technical Review, 54 (2004), 2, pp.3-10.
  49. Ristić, S., et al., Presentation of the facilities, methods and results of turbulence investigation in the VTI's wind tun-nels, Turbulence Workshop - International Symposium, 31.08- 2.09. 2015, Faculty of Mechanical Engineering, Uni-versity of Belgrade, turbulenceworkshop.mas.bg.ac.rs/first_day, Proceedings, ISBN 978-86-7083-865-9