This paper studies the characteristics of the propeller-wing coupled flow field of the channel wing configuration. It also carries out an airfoil optimization with the aim to improve the lift efficiency at Short Takeoff and Landing (STOL) condition. By adopting the momentum source method and carrying out the real blade model CFD analysis of the propeller-wing interaction flow field, this paper first analyzes the feasibility of the momentum source method for the design. Then, to obtain a new airfoil with coupled aerodynamic features, an parameterized model with Free-Form Deformation (FFD) method is established to optimize the airfoil of the channel wing, and the changes of optimal airfoil parameters and the flow field are analyzed. In the end, the CFD analysis for three dimensional channel wing is carried out to compare and verify the two-dimensional airfoil optimization results. The results show that the Multiple Reference Frame (MRF) method cannot correctly analyze the flow field of over-the-wing propeller, while the momentum source method is more consistent with the unsteady sliding mesh method. The genetic algorithm optimization using the two-dimensional momentum source CFD method is effective. With the protection of the half-duct, the advantages of two-dimensional optimization airfoil have been effectively inherited in the three-dimensional configuration. The airfoil design for channel wing configuration should focus on the curvature variation of the wing surface. In this paper, the Coanda effect is enhanced by increasing the curvature of the airfoil near the propeller and maintaining the attached flow, which achieved aerodynamic lift-increase. The lift of the optimal channel wing increases by 22.51%, and the high pressure area is significantly reduced behind the propeller and second peaks of suction appears, while drag is still negative.
[1] PASAMANICK J. Langley full-scale-tunnel tests of the custer channel wing airplane:NACA RM-L53A09[R]. Washington, D.C.:NASA, 1953.
[2] JOHNSON J L, WHITE E R. Exploratory low-speed wind-tunnel investigation of advanced commuter configurations including an over-the-wing propeller design:AIAA-1983-2531[R]. Reston, VA:AIAA, 1983.
[3] JOHNSON J L, WHITE E R. Over-the-wing propeller:U.S. Patent No. 4629147[P]. 1986.
[4] GUNTHER C, MARCHMAN J, VANBLARCOM R. Comparison of channel wing theoretical and experimental performance:AIAA-2000-0257[R]. Reston, VA:AIAA, 2000.
[5] ENGLAR R J, CAMPBELL B A. Pneumatic channel wing powered lift advanced super-stol aircraft:AIAA-2002-3275[R]. Reston, VA:AIAA, 2002.
[6] ENGLAR R J, CAMPBELL B A. Development of pneumatic channel wing powered-lift advanced SuperSTOL aircraft:AIAA-2002-2929[R]. Reston, VA:AIAA, 2002.
[7] MÜLLER L, HEINZE W, KOŽULOVIĆD, et al. Aerodynamic installation effects of an over-the-wing propeller on a high-lift configuration[J]. Journal of Aircraft, 2014, 51(1):249-258.
[8] MÜLLER L, FRIEDRICHS J, KOZULOVIC D. Unsteady flow simulations of an over-the-wing propeller configuration[C]//AIAA/ASME/SAE/ASEE Joint Propulsion Conference. Reston, VA:AIAA, 2014:28-30.
[9] BECK S C, MÜLLER L, LANGER S C. Numerical assessment of the vibration control effects of porous liners on an over-the-wing propeller configuration[J]. The Aeronautical Journal, 2016, 7(2):1-12.
[10] WANG H B, ZHU X, ZHOU Z. Numerical simula-tion of the propeller/wing interactions at low Reynolds number[C]//International Council of the Aeronautical Sciences, 2016.
[11] 王红波, 祝小平,周洲,等. 垂直起降飞机新型气动布局设计分析[J].西北工业大学学报, 2017, 35(2):189-196. WANG H B, ZHU X P, ZHOU Z,et al. New configuration design and analysis for a vertical take-off/hovering solar powered aircraft[J]. Journal of Northwestern Polytechnical University, 2017, 35(2):189-196(in Chinese).
[12] MARCUS E A, VRIES R D, KULKARNI A R, et al. Aerodynamic investigation of an over-the-wing propeller for distributed propulsion[C]//AIAA Aerospace Sciences Meeting. Reston, VA:AIAA, 2018.
[13] COCHRANE J A, CARROS R J. Hybrid upper surface blown flap propulsive-lift concept for the QSRLP[J]. Journal of Aircraft, 1976, 13(11):855-860.
[14] HARRISON N A, VASSBERG J C, DEHAAN M A, et al. The design and test of a swept wing upper surface blowing concept[C]//AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition. Reston, VA:AIAA, 2013.
[15] DRǍGAN V. A study of conventional upper surface blown wing configurations[J]. Review of the Air Force Academy, 2012.
[16] PFINGSTEN R C, KAMRUZZAMAN M. Use of upper surface blowing and circulation control for gapless high-lift configurations[C]//Ceas/katnet Conference on Key Aerodynamics Technologies, 2005.
[17] KEEN E. A conceptual design methodology for predicting the aerodynamics of upper surface blowing on airfoils and wings[D]. Blacksburg, VA:Virginia Polytechnic Institute & State University, 2004.
[18] HILL G A, KANDIL O A, HAHN A S. Aerodynamic investigations of an advanced over-the-wing nacelle transport aircraft configuration[J]. Journal of Aircraft, 2009, 46(1):25-35.
[19] RAJAGOPALAN R G, LIM C K. Laminar flow analysis of a rotor in hover[J]. Journal of the American Helicopter Society, 1991, 36(1):12-23.
[20] CHAFFIN M S, BERRY J D. Navier-Stokes simulation of a rotor using a distributed pressure disk method[C]//Proceedings of 51st Annual Forum of American Helicopter Society, 1995.
[21] 夏贞锋. 螺旋桨滑流数值模拟方法及气动干扰研究[D]. 西安:西北工业大学, 2015. XIA Z F. Numerical approaches of propeller slipstream simulations and aerodynamic interference analysis[D]. Xi'an:Northwestern Polytechnical University, 2015(in Chinese).
[22] LE CHUITON F. Actuator disc modelling for helicopter rotors[J]. Aerospace Science and Technology, 2004, 8(4):285-297.
[23] KHIER W. Time-accurate versus actuator disk simulations of complete helicopters[C]//High Performance Computing in Science and Engineering, 2006:209-220.
[24] 童自立, 孙茂. 共轴式双旋翼流动的N-S方程模拟[J]. 航空学报, 1998, 19(1):1-5. TONG Z L, SUN M. Navier-Stokes calculations of coaxial rotor aerodynamics[J]. Acta Aeronautica et Astronautica Sinica, 1998, 19(1):1-5(in Chinese).
[25] 宋长虹, 林永峰,陈文轩,等. 基于动量源方法的涵道尾桨CFD分析[J]. 直升机技术, 2009(1):6-11. SONG C H, LIN Y F, CHEN W X, et al. CFD Analysis for the ducted tail rotor based on momentum-source method[J]. Helicopter Technique, 2009(1):6-11(in Chinese).
[26] GRUNWALD K J, GOODSON K W. Aerodynamic loads on an isolated shrouded-propeller configuration for angels of attack from -10° to 110°[R].Washington, D.C.:NASA, 1962.
[27] DORFLING J, ROKHSAZ K. Non-linear aerodynamic modeling of airfoils for accurate blade element propeller performance predictions[C]//32nd AIAA Applied Aerodynamic Conference. Reston, VA:AIAA, 2014.
[28] UHLIG D V, SELIG M S. Post stall propeller behavior at low reynolds numbers[C]//AIAA Aerospace Sciences Meeting and Exhibit. Reston, VA:AIAA, 2008.
[29] 许和勇, 叶正寅. 涵道螺旋桨与孤立螺旋桨气动特性的数值模拟对比[J]. 航空动力学报, 2011, 26(12):2820-2825. XU H Y, YE Z Y. Numerical simulation and comparison of aerodynamic characteristics between ducted and isolated propellers[J]. Journal of Aerospace Power, 2011, 26(12):2820-2825(in Chinese).
[30] 苏运德, 叶正寅,许和勇. 桨尖间隙和双桨间距对涵道螺旋桨气动性能的影响[J]. 航空动力学报, 2014, 29(6):1468-1475. SU Y D, YE Z Y, XU H H. Influence of tip clearance and propeller separation space on aerodynamic performance of ducted propeller[J]. Journal of Aerospace Power, 2014, 29(6):1468-1475(in Chinese).
[31] 李晓华, 郭正,陈清阳. 涵道螺旋桨气动特性数值模拟[J]. 国防科技大学学报, 2015(4):31-35. LI X H, GUO Z, CHEN Q Y. Numerical simulation of ducted rotor's aerodynamic characteristics[J]. Journal of National University of Defense Technology, 2015(4):31-35(in Chinese).
[32] KOSHAKJI A, QUARTERONI A, ROZZA G. Free form deformation techniques applied to 3D shape optimization problems[J]. Communications in Applied & Industrial Mathematics, 2013, 4.
CJA