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Differential infrared thermography for boundary layer transition detection on pitching rotor blade models

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Abstract

Differential infrared thermography (DIT) was investigated and applied for the detection of unsteady boundary layer transition locations on a pitching airfoil and on a rotating blade under cyclic pitch. DIT is based on image intensity differences between two successively recorded infrared images. The images were recorded with a high framing rate infrared camera. A pitching NACA0012 airfoil served as the first test object. The recorded images were used in order to investigate and to further improve evaluation strategies for periodically moving boundary layer transition lines. The measurement results are compared with the results of unsteady CFD simulations based on the DLR-TAU code. DIT was then used for the first time for the optical measurement of unsteady transition locations on helicopter rotor blade models under cyclic pitch and rotation. Image de-rotation for tracking the blade was employed using a rotating mirror to increase exposure time without causing motion blur. The paper describes the challenges that occurred during the recording and evaluation of the data in detail. However, the results were found to be encouraging to further improve the method toward the measurement of unsteady boundary layer transition lines on helicopter rotor models in forward flight.

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Abbreviations

A, B:

Measurement images

b :

Breadth (m)

c :

Chord (m)

c p :

Specific heat (J/K)

f :

Frequency (Hz)

f acq :

Camera acquisition frequency (Hz)

f m :

Rotational mirror frequency (Hz)

f r :

Rotor frequency (Hz)

h :

Heat transfer coefficient (W/(m2K))

k :

Reduced frequency (k = πfc/U ∞)

k tip :

Reduced blade tip frequency (k tip = πf r c/U tip)

M tip :

Blade tip Mach number

N :

N-factor used for the eN method

r :

Radial coordinate (m)

R :

Blade tip radius (m)

Re x :

Local Reynolds number

Re tip :

Blade tip Reynolds number

s :

Span (m)

St :

Stanton number (St = h/(U ∞ ρc p))

t :

Time (s)

t exp :

Camera exposure time (s)

T :

Period (s)

T′ :

Temperature (°C)

T′∞ :

Freestream temperature (°C)

U ∞ :

Freestream velocity (m/s)

U tip :

Blade tip speed (m/s)

x :

Chord-wise coordinate (m)

x tr :

Transition location (m)

y+:

Normalized wall distance

α :

Angle of attack (°)

α A, α B :

Instantaneous angles of attack (°)

α CFD :

Angle of attack in the CFD computation (°)

α Exp :

Angle of attack in the experiment (°)

α max :

Maximum angle of attack (°)

α mean :

Mean angle of attack (°)

α min :

Minimum angle of attack (°)

ψ:

Rotor azimuth (°)

Ω:

Angular velocity of the rotor (°/s)

ρ:

Density (kg/m3)

Δα :

Amplitude (°)

ΔT′:

Temperature difference (K)

Δt :

Time delay (s)

References

  • Astarita T, Cardone G, Carlomagno GM, Meola C (2000) A survey on infrared thermography for convective heat transfer measurements. Opt Laser Technol 32(7–8):593–610

    Article  Google Scholar 

  • Banks DW, van Dam CP, Shiu HJ, Miller GM (2000) Visualization of in-flight flow phenomena using infrared thermography. In: Proceedings of the 9th international symposium on flow visualization, Edinburgh

  • Becker JV (1940) Boundary-layer transition on the N.A.C.A. 0012 and 23012 airfoils in the 8-foot high-speed wind tunnel. NACA Report ACR-L-682

  • Brandon JM, Manuel GS, Wright RE, Holmes BJ (1990) In-flight flow visualization using infrared imaging. J Aircr 27(6):612–618

    Article  Google Scholar 

  • Chandrasekhara MS, Wilder MC (2003) Heatflux gauge studies of compressible dynamic stall. AIAA J 41(5):757–762. doi:10.2514/2.2019

    Article  Google Scholar 

  • Chandrasekhara MS, Wilder MC, Carr LW (1996) On the competing mechanisms of compressible dynamic stall. Paper AIAA-96-1953, 27th AIAA fluid dynamics conference, New Orleans, Louisiana, USA

  • Costantini M, Fey U, Henne U, Klein C (2012) Influence of non-adiabatic model surface on transition measurements using the Temperature-Sensitive Paint technique in a cryogenic wind tunnel. Paper AIAA-2012-2830, 42nd AIAA fluid dynamics conference and exhibit, New Orleans, Louisiana, USA

  • De Luca L, Carlomagno GM, Buresti G (1990) Boundary layer diagnostics by means of an infrared scanning radiometer. Experiments in Fluids 9(3):121–128

    Article  Google Scholar 

  • Gerhold T, Friedrich O, Galle M (1997) Calculation of complex three-dimensional configurations employing the DLR-TAU-code. Paper AIAA-97-0167, 35th AIAA aerospace sciences meeting and exhibit, Reno, NV, USA

  • Heister CC (2013) Numerical investigation of laminar-turbulent transition mechanisms for helicopter rotors in forward flight. In: Proceedings of the 69th annual forum, American Helicopter Society International, Phoenix, Arizona, USA

  • Junger C, Gardner AD (2013) Numerische Untersuchung des Ein-Meter-Windkanals mit offener und geschlossener Messstrecke. German Aerospace Center (DLR) Report IB 224-2013 A93

  • Kallinderis Y, Khawaja A, McMorris H (1996) Hybrid prismatic/tetrahedral grid generation for complex geometries. AIAA J 34(2):291–298

    Article  MATH  Google Scholar 

  • Klein C, Henne U, Sachs W, Beifuss U, Ondrus V, Bruse M, Lesjak R, Löhr M (2014) Application of carbon nanotubes (CNT) and temperature-sensitive paint (TSP) for the detection of boundary layer transition. In: Proceedings of the AIAA 52nd aerospace sciences meeting, National Harbor, Maryland, USA, AIAA 2014-1482

  • Kowalewski T, Ligrani P, Dreizler A, Schulz C, Fey U (2007) Temperature and heat flux. In: Tropea C, Yarin AL, Foss JF (eds) Handbook of experimental fluid mechanics. Springer, Berlin

    Google Scholar 

  • Krumbein A, Krimmelbein N, Schrauf G (2009a) Automatic transition prediction in hybrid flow solver, part 1: methodologies and sensitivities. J Aircr 46(4):1176–1190

    Article  Google Scholar 

  • Krumbein A, Krimmelbein N, Schrauf G (2009b) Automatic transition prediction in hybrid flow solver, part 2: practical application. J Aircr 46(4):1191–1199

    Article  Google Scholar 

  • Lorber P, Carta F (1992) Unsteady transition measurements on a pitching three-dimensional wing. In: Proceedings of the 5th Symposium on Numerical and Physical Aspects of Aerodynamic Flows, Long Beach, CA, USA

  • Mori M, Novac L, Sekavčnik M (2007) Measurements on rotating blades using IR thermography. Exp Thermal Fluid Sci 32(2):387–396

    Article  Google Scholar 

  • NASA (1972) Space shuttle aerothermodynamics technology conference, vol II: heating. NASA-TM-X-2507

  • Raffel M, Heineck JT (2014) Mirror based image de-rotation for aerodynamic rotor measurements. AIAA J 52(6):1337–1341

    Article  Google Scholar 

  • Raffel M, Merz CB (2014) Differential infrared thermography for unsteady boundary layer transition measurements. AIAA J 52(9):2090–2093

    Article  Google Scholar 

  • Raffel M, de Gregorio F, de Groot K, Schneider O, Gibertini G, Seraudie A (2011) On the generation of a helicopter aerodynamic database. Aeronaut J 115(1164):103–112

    Google Scholar 

  • Richter K, Schülein E (2014) Boundary-layer transition measurements on hovering helicopter rotors by infrared thermography. Experiments in Fluids 55(1755)

  • Richter K, Le Pape A, Knopp T, Costes M, Gleize V, Gardner AD (2011) Improved two-dimensional dynamic stall prediction with structured and hybrid numerical methods. J Am Helicopter Soc 56(4):1–12

    Article  Google Scholar 

  • Richter K, Koch S, Gardner AD, Mai H, Klein A, Rohardt C-H (2014) Experimental investigation of unsteady transition on a pitching rotor blade airfoil. J Am Helicopter Soc. doi:10.4050/JAHS.59.012001

  • Rohardt CH (1986) Strömungssichtbarmachung an Hubschrauberrotorblättern mittels Acenaphthen. German Aerospace Center (DLR) Report IB 129-86/18

  • Schlichting H, Gersten K (2003) Boundary Layer Theory, 8th edn. Springer, Berlin. ISBN: 3540662707

  • Schülein E, Rosemann H, Schaber S (2012) Transition detection and skin friction measurements on rotating propeller blades. Paper AIAA-2012-3202, 28th AIAA aerodynamic measurement technology, ground testing and flight testing conference, New Orleans, Louisiana, USA. doi:10.2514/6.2012-3202

  • Schultz DL, Jones TV (1973) Heat transfer measurements in short-duration hypersonic facilities. AGAR Dograph 165, AGARD

  • Schwamborn D, Gardner AD, von Geyr H, Krumbein A, Lüdeke H, Stürmer (2008) A development of the TAU-code for aerospace applications. In: Proceedings of the 50th NAL ICAST, Bangalore, India

  • Spalart PR, Allmaras SR (1992) A one-equation model for aerodynamic flows. Paper AIAA-92-0439, 30th AIAA Aerospace Sciences Meeting and Exhibit, Reno, NV, USA

  • Tanner WH, Yaggy PF (1966) Experimental boundary layer study on hovering rotors. J Am Helicopter Soc 3:22–37

    Article  Google Scholar 

  • Van Dam CP, Shiu HJ, Banks DW (1998) Remote in-flight boundary layer transition visualization using infrared thermography. In: Proceedings of the 8th international symposium on flow visualization, Sorrento, Italy

  • Wadcock AJ, Yamauchi GK, Driver DM (1999) Skin friction measurements on a hovering full-scale tilt rotor. J Am Helicopter Soc 44(4):312–319

    Article  Google Scholar 

  • Yorita D, Asai K, Klein C, Henne U, Schaber S (2012) Transition detection on rotating propeller blades by means of temperature-sensitive paint. Paper AIAA-2012-1187, 50th AIAA Aerospace Sciences Meeting, Nashville, Tennessee, USA. doi:10.2514/6.2012-1187

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Acknowledgments

The support of our colleagues A. D. Gardner, K. de Groot and M. Krebs is highly appreciated. Furthermore, the authors would like to thank J. Sarfels and M. Hayk for making up-to-date infrared cameras available.

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Authors and Affiliations

  1. Institute of Aerodynamics and Flow Technology, German Aerospace Center, Göttingen, Germany

    Markus Raffel, Christoph B. Merz, Till Schwermer & Kai Richter

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  1. Markus Raffel
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  2. Christoph B. Merz
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  3. Till Schwermer
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  4. Kai Richter
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Correspondence to Markus Raffel.

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Raffel, M., Merz, C.B., Schwermer, T. et al. Differential infrared thermography for boundary layer transition detection on pitching rotor blade models. Exp Fluids 56, 30 (2015). https://doi.org/10.1007/s00348-015-1905-y

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