Wind-Tunnel and CFD Investigations Focused on Transition and Performance Predictions of Laminar Wings
Abstract
This paper is a continuation of the paper recently published by Hue et al. (“Experimental and Numerical Methods for Transition and Drag Predictions of Laminar Airfoils,” AIAA Journal, Vol. 53, No. 9, Sept. 2015, pp. 2694–2712) that focused on transition and drag predictions of laminar airfoils. The extension of such studies to three-dimensional configurations representative of modern civil aircraft is a further step toward the implementation of natural laminar-flow technologies. The present work, therefore, focuses on validating the laminar design of a low-swept wing for business jet applications. In 2015, an experimental campaign was carried out in the European Transonic Windtunnel, and included laminar/turbulent transition measurements with temperature-sensitive paint at Mach and Reynolds numbers typical of cruise flight conditions. Subsequently, fluid dynamics computations were performed on this aircraft geometry either with a Reynolds-averaged Navier–Stokes solver using both Tollmien–Schlichting and crossflow transition criteria, or with a boundary-layer code using either database methods for transition location or exact stability analyses. In this paper, experimental and numerical transition predictions are compared for three representative cases corresponding to different angles of attack. The agreement that is achieved is satisfactory, and extended regions of laminar flow are observed on the wing at cruise lift levels. In these conditions, the drag reduction can account for 10–15% of the aircraft drag.
References
[1] , “Overview of the Laminar Flow Control,” NASA TP-1998-208705, 1998, http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19980232017.pdf [retrieved Jan. 2017].
[2] , “Subsonic Natural-Laminar Flow Airfoils,” Natural Laminar Flow and Laminar Flow Control, edited by Barnwell R. W. and Hussaini M. Y., Springer–Verlag, New York, 1992, pp. 143–176. doi:https://doi.org/10.1007/978-1-4612-2872-1_4
[3] , “Shape Optimization for Delay of Laminar–Turbulent Transition,” AIAA Journal, Vol. 44, No. 5, May 2006, pp. 1009–1024. doi:https://doi.org/10.2514/1.12431 AIAJAH 0001-1452
[4] , “Design of the Low Speed NLF (1)-0414F and the High-Speed HSNLF(1)-0213 Airfoils with High Lift Systems,” Research in Natural Laminar Flow and Laminar Flow Control, 1987, pp. 637–671; also NASA CP-2487, 1987, http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19900003224.pdf [retrieved Jan. 2017].
[5] , “Wind Tunnel Results of the High-Speed NLF(1)-0213 Airfoil,” Research in Natural Laminar Flow and Laminar Flow Control, Pt. 3, 1987, pp. 697–726; also NASA CP-2487, 1987, http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19900003226.pdf [retrieved Jan. 2017].
[6] , “Wind Tunnel Results for a High-Speed, Natural Laminar-Flow Airfoil Designed for General Aviation Aircraft,” NASA TM 87602, 1985, http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19880004696.pdf [retrieved Jan. 2017].
[7] , “Natural-Laminar-Flow Airfoil Development for a Lightweight Business Jet,” Journal of Aircraft, Vol. 40, No. 4, July–Aug. 2003, pp. 609–615. doi:https://doi.org/10.2514/2.3145
[8] , “High Reynolds Number Transition Experiments in the ETW Test Facility with the Pathfinder Model,” Proceedings of the 5th European Conference on Computational Fluid Dynamics, ECCOMAS CFD 2010, 2010.
[9] , “Complementary Numerical and Experimental Data Analysis of the ETW Telfona Pathfinder Wing Transition Tests,” 49th Aerospace Sciences Meeting, AIAA Paper 2011-881, Jan. 2011. doi:https://doi.org/10.2514/6.2011-881
[10] , “Experimental and Numerical Methods for Transition and Drag Predictions of Laminar Airfoils,” AIAA Journal, Vol. 53, No. 9, Sept. 2015, pp. 2694–2712. doi:https://doi.org/10.2514/1.J053788 AIAJAH 0001-1452
[11] , “Boundary Layer Transition on a 10-Degree Cone: Wind Tunnel/Flight Data Correlation,” 18th Aerospace Sciences Meeting, AIAA Paper 1980-0154, Jan. 1980. doi:https://doi.org/10.2514/6.1980-154
[12] , “Hotwires in Pressurized, Cryogenic Environment—It Works!,” 50th AIAA Aerospace Sciences Meeting, AIAA Paper 2012-0105, Jan. 2012. doi:https://doi.org/10.2514/6.2012-105
[13] , “A Suggested Semi-Empirical Method for the Calculation of the Boundary-Layer Transition Region,” Dept. of Aerospace Engineering, Univ. of Delft, Rept. VTH-74, Delft, The Netherlands, 1956.
[14] , “Transition Pressure Gradient and Stability Theory,” Douglas Aircraft, Rept. ES-26388, 1956.
[15] , “Transition Prediction and Linear Stability Theory,” AGARD Conference Proceedings, No. 224, Paris, 1977.
[16] , “Using cryoTSP as a Tool for Transition Detection and Instability Examination at High Reynolds Numbers,” New Results in Numerical and Experimental Fluid Mechanics VI, edited by Tropea C., Suad J., Heinemann H.-J., Henke R. and Hönlinger H., Vol. 96, Springer–Verlag, Berlin, 2008, pp. 227–234. doi:https://doi.org/10.1007/978-3-540-74460-3_28
[17] , “Development of a Highly Sensitive Temperature-Sensitive Paint for Measurements Under Cryogenic Temperatures (100–160 K) Conditions,” 54th AIAA Aerospace Sciences Meeting, AIAA Paper 2016-0650, Jan. 2016. doi:https://doi.org/10.2514/6.2016-0650
[18] , “The Method for Transition Prediction: Historical Review of Work at TU Delft,” 38th Fluid Dynamics Conference and Exhibit, AIAA Paper 2008-3830, June 2008. doi:https://doi.org/10.2514/6.2008-3830.
[19] , “Implicit Implementation of the Full Transition Criterion,” 21st Applied Aerodynamics Conference, AIAA Paper 2003-4066, June 2003. doi:https://doi.org/10.2514/6.2003-4066
[20] , “Transition Prediction in Transonic Flow,” Symposium Transsonicum III, edited by Zierep J. and Oertel H.,
International Union of Theoretical and Applied Mechanics , Springer, Berlin, 1989, pp. 253–262. doi:https://doi.org/10.1007/978-3-642-83584-1_21[21] , “ELFIN II Subtask 2.3: Database Method: Development and Validation of the Simplified Method for Pure Crossflow Instability at Low Speed,” European Laminar Flow Investigation II TR 145, 1996.
[22] , “Numerical Study of Laminar Nacelles: Natural and Hybrid Laminar Flow Designs,” International Journal of Engineering Systems Modelling and Simulation, Vol. 6, Nos. 3–4, 2014, pp. 191–204. doi:https://doi.org/10.1504/IJESMS.2014.063124
[23] , “Automatic Transition Predictions Using Simplified Methods,” AIAA Journal, Vol. 47, No. 11, 2009, pp. 2676–2684. doi:https://doi.org/10.2514/1.42990 AIAJAH 0001-1452
[24] , “Natural Laminar Flow Wing for Supersonic Conditions: Wind Tunnel Experiments, Flight Test and Stability Computations,” Progress in Aerospace Sciences, Vol. 79, Nov. 2015, pp. 64–91. doi:https://doi.org/10.1016/j.paerosci.2015.07.003 PAESD6 0376-0421
[25] , “Database Approach for 2D Flow Transition Prediction in a RANS Code,” 46th AIAA Fluid Dynamics Conference, AIAA Paper 2016-3488, June 2016. doi:https://doi.org/10.2514/6.2016-3488
[26] , “Laminar Instability Theory and Transition Criteria in Two and Three-Dimensional Flow,” La Recherche Aérospatiale (English Edition), No. 2, 1984, pp. 45–63.
[27] , “Application of Laminar–Turbulent Transition Criteria in Navier–Stokes Computations,” AIAA Journal, Vol. 46, No. 5, 2008, pp. 1182–1190. doi:https://doi.org/10.2514/1.30215 AIAJAH 0001-1452
[28] , “Overview of Laminar–Turbulent Transition Investigations at ONERA Toulouse,” 41st AIAA Fluid Dynamics Conference and Exhibit, AIAA Paper 2011-3074, June 2011. doi:https://doi.org/10.2514/6.2011-3074
[29] , “Theoretical and Experimental Study of Low Reynolds Number Transitional Separation Bubbles,” Conference on Low Reynolds Number Airfoil Aerodynamics, 1985.
[30] , “Calculation of the Laminar Boundary Layer and Prediction of Transition on a Sheared Wing,” Reports and Memoranda of the Aeronautical Research Council, 3787, 1976.
[31] , “Validation of a Near-Body and Off-Body Grid Partitioning Methodology for Aircraft Aerodynamic Performance Prediction,” Computers & Fluids, Vol. 117, Aug. 2015, pp. 196–211. doi:https://doi.org/10.1016/j.compfluid.2015.05.021
[32] Anon., “Mesh Generation Software for CFD—Pointwise,” 2016, http://www.pointwise.com [retrieved Oct. 2016].
[33] , “The ONERA elsA CFD Software: Input from Research and Feedback from Industry,” Mechanics and Industry, Vol. 14, No. 3, 2013, pp. 159–174. doi:https://doi.org/10.1051/meca/2013056
[34] , “Numerical Solution of the Euler Equations by Finite Volume Methods Using Runge Kutta Time Stepping Schemes,” 14th Fluid and Plasma Dynamics Conference, AIAA Paper 1981-1259, June 1981. doi:https://doi.org/10.2514/6.1981-1259
[35] , “A One-Equation Turbulence Model for Aerodynamic Flows,” 30th Aerospace Sciences Meeting and Exhibit, AIAA Paper 1992-0439, Jan. 1992. doi:https://doi.org/10.2514/6.1992-439
[36] , “Strategies for Turbulence Modelling and Simulation,” International Journal of Heat and Fluid Flow, Vol. 21, No. 3, 2000, pp. 252–263. doi:https://doi.org/10.1016/S0142-727X(00)00007-2 IJHFD2 0142-727X
[37] , “DPW-6: Drag Analyses and Increments Using Different Geometries of the Common Research Model Airliner,” Journal of Aircraft, Jan. 2017. doi:https://doi.org/10.2514/1.C034139
[38] , “Far-Field/Near-Field Drag Balance Applications of Drag Extraction in CFD,” CFD-Based Aircraft Drag Prediction and Reduction,
VKI Lecture Series 2003-02 , von Karman Inst. for Fluid Dynamics, Rhode-Saint-Genèse, Belgium, Nov. 2003.[39] , “Computational Drag Prediction of the DPW4 Configuration Using the Far-Field Approach,” Journal of Aircraft, Vol. 48, No. 5, Sept.–Oct. 2011, pp. 1658–1670. doi:https://doi.org/10.2514/1.C031337