Abstract
A computerized infrared (IR) scanning radiometer is employed to characterize the boundary layer development over a model wing, having a Göttingen 797 cross-section, by measuring the temperature distribution over its heated surface. The Reynolds analogy is used to relate heat transfer measurements to skin friction. The results show that IR thermography is capable of rapidly detecting location and extent of transition and separation regions of the boundary layer over the whole surface of the tested model wing. Thus, the IR technique appears to be a suitable and effective diagnostic tool for aerodynamic research in wind tunnels.
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Abbreviations
- c :
-
airfoil chord
- c f :
-
local skin friction coefficient = 2τ/(ϱ V 2)
- c p :
-
specific heat coefficient at constant pressure
- h :
-
local convective heat transfer coefficient
- Nu :
-
Nusselt number = h x/λ
- Nu c :
-
Nusselt number based on airfoil chord = h c/λ
- Pr :
-
Prandtl number c p μ/λ
- Q j :
-
wall heat flux due to Joule heating
- Q l :
-
heat flux loss
- Re :
-
Reynolds number ϱ V x/μ
- Re c :
-
Reynolds number based on airfoil chord = ϱ V c/μ
- St :
-
Stanton number = h/ϱc p V
- T w :
-
wall temperature
- T aw :
-
adiabatic wall temperature
- V :
-
velocity of the free stream
- x :
-
chordwise spatial coordinate
- α :
-
angle of attack
- λ :
-
thermal conductivity coefficient
- μ :
-
dynamic viscosity coefficient
- ϱ :
-
mass density
- τ:
-
wall shear stress
References
Arena, A. V.; Mueller, T. J. 1980: Laminar separation, transition, and turbulent reattachment near the leading edge of airfoils. AIAA J. 18, 747–753
Batill, S. M.; Mueller, T. J. 1981: Visualization of transition in the flow over an airfoil using the smoke-wire technique. AIAA J. 19, 340–345
Bobbitt, P. J.; Waggoner, E. G.; Harvey, W. D.; Dagenhart, J. R. 1985: A faster transition to laminar flow. SAE Tech. Paper 851855
Bynum, D. S.; Hube, F. K.; Key, C. M.; Diek, P. M. 1976: Measurement and mapping of aerodynamic heating with an infrared camera. AEDC Rept. TR-76-54, pp. 1–33
Carlomagno, G. M.; de Luca, L. 1987: Heat transfer measurements by means of infrared thermography. In: Flow visualization IV. (ed. Veret, C.). pp. 611–616. Washington: Hemisphere
Carlomagno, G. M.; de Luca, L. 1989: Infrared thermography in heat transfer. In: Handbook of flow visualization (ed. Yang, W. J.). pp. 531–553. Washington: Hemisphere
Carlomagno, G. M.; de Luca, L.; Alziary, T. 1989: Heat transfer measurements with an infrared camera in hypersonic flow. In: Computer and experiments in fluid flow (eds. Carlomagno, G. M.; Brebbia, C. A.), pp. 467–476. Berlin, Heidelberg, New York: Springer
Ceresuela, R.; Betremieux, A.; Caders, J. 1965: Mesure de l'échauffement cinétique dans les souffleries hypersoniques au moyen de peintures thermosensibles. Rech. Aérosp. 109, 13–19
Cooper, T. E.; Field, R. J.; Meyer, J. F. 1975: Liquid crystal thermography and its application to the study of convective heat transfer. J. Heat Transfer 97, 442–450
Fernholz, H. H.; Finley, H. A. 1980: A critical commentary on mean flow data for two-dimensional compressible turbulent boundary layers. AGARD AG-253
Freymuth, P.; Bank, W.; Palmer, M. 1985: Use of titanium tetrachloride for visualization of accelerating flow around airfoils. In: Flow visualization III. (ed. Yang, W. J.). pp. 99–105. Washington: Hemisphere
Heath, D. M.; Winfree, W. P.; Carraway, D. L.; Heyman, J. S. 1987: Remote non-contacting measurements of heat transfer coefficients for detection of boundary layer transition in wind tunnel tests. Proc. of ICIAFS'87. pp. 135–139. Williamsburg/VA
Marchman, J. F., III; Abtahi, A. A. 1985: Aerodynamics of an aspect ratio 8 wing at low Reynolds numbers. J. Aircraft 22, 628–634
Merzkirch, W. 1987: Flow visualization, 2nd edn. New York: Academic Press
Monti, R.; Zuppardi, G. 1987: Computerized thermographic technique for the detection of boundary layer separation. In: Aerodynamic data accuracy and quality: requirements and capabilities in wind tunnel testings. AGARD Conf. Preprint N. 429. pp. 30/1 15
Mueller, T. J.; Pohlen, L. J.; Conigliaro, P. E.; Jansen, B. J. 1983: The influence of free-stream disturbances on low Reynolds number airfoil experiments. Exp. Fluids 1, 3–14
Mueller, T. J.; Brendel, M.; Schmidt, G. S. 1987: Visualization of the laminar separation bubble on airfoils at low Reynolds numbers. In: Flow visualization IV. (ed. Veret, C.). pp. 359–364. Washington: Hemisphere
Ostowari, C. 1984: A rapid technique for measuring and visualizing the extent of separated flow. Exp. Fluids 2, 67–72
Quast, A. 1987: Detection of transition by infrared image technique. Proc. of ICIAFS'87, pp. 125–134. Williamsburg/VA
Render, P. M.; Stollery, J. L.; Williams, B. R. 1986: Aerofoils at low Reynolds numbers. Prediction and experiment. In: Numerical and physical aspects of aerodynamic flows III. (ed. Cebeci, T.). pp. 155–167. Berlin, Heidelberg, New York: Springer
Settles, G. S.; Teng, H. Y. 1983: Flow visualization methods for separated three-dimensional shock wave/turbulent boundary layer interactions. AIAA J. 21, 390–397
Tien, K. K.; Sparrow, E. M. 1979: Local heat transfer and fluid flow characteristics for airfoil oblique or normal to a square plate. Int. J. Heat Mass Transfer 22, 349–360
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de Luca, L., Carlomagno, G.M. & Buresti, G. Boundary layer diagnostics by means of an infrared scanning radiometer. Experiments in Fluids 9, 121–128 (1990). https://doi.org/10.1007/BF00187411
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DOI: https://doi.org/10.1007/BF00187411