Solid Mechanics and Vehicle Conceptual Design

High⁃precision simulation of aeroelastic characteristics of TEF rotor based on CFD/CSD coupling

  • Hualong WANG ,
  • Xiayang ZHANG ,
  • Guoqing ZHAO ,
  • Qijun ZHAO ,
  • Li MA
Expand
  • National Key Laboratory of Helicopter Aeromechanics,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China

Received date: 2023-11-27

  Revised date: 2023-12-28

  Accepted date: 2024-03-15

  Online published: 2024-03-22

Supported by

National Key Laboratory Foundation of China(61422202201);National Natural Science Foundation of China(12102186);Young Elite Scientists Sponsorship Program by CAST(2022QNRC001)

Abstract

To analyze the aeroelasticity of Trailing Edge Flap (TEF) rotors in forward flight, a high-precision analysis method based on Computational Fluid Dynamics/Computational Structural Dynamics (CFD/CSD) coupling is established. A set of moving-embedded grid method for rotors with TEF is developed by the parametric method. In terms of aerodynamic analysis, the high-precision CFD method, based on the traditional aerodynamic model, is introduced to accurately simulate the unsteady flow field and aerodynamic characteristics of the rotor. In terms of structure, the dynamic model of rigid TEFs is established, the influence of the rigid TEF motion on the rotor system is considered in the form of additional mass, damping, stiffness and other matrices, and the nonlinear dynamic equation of the rotor system is derived based on Hamilton’s principle and Timoshenko beam model. An elastic grid deformation method based on algebraic transformation is adopted, and the unsteady fluid-solid coupling strategy is developed. Results comparison of the aeroelastic loads of the model rotor and the SA349/2 rotor verifies the effectiveness of the CFD/CSD coupling method. On this basis, taking the SMART rotor with TEF as an example, the calculation results are compared with the equivalent normal force coefficient of the blade sections. Emphasis is placed on the analysis of the Fulton model rotor, studying the variation of blade root torque in hover and flap moment amplitude in forward flight, and comparing them with literature results. Results show that the proposed CFD/CSD coupling method can improve the analysis accuracy of the unsteady aeroelastic load of the rotor, and accurately capture the Blade-Vortex Interaction (BVI) phenomenon of the low-speed forward flight rotor, with the average error of flap bending moment controlled at 11.68%. Meanwhile, the natural frequency error of the blade with TEF is smaller than 4.0%, and the average error of flap bending moment amplitude of the blade root is 15.15%, meaning that the aeroelastic characteristics of the TEF can be effectively simulated. Under the single TEF control law, the hub vertical force Fz of the Fulton rotor can be effectively controlled, and the load amplitude is reduced by more than 80%.

Cite this article

Hualong WANG , Xiayang ZHANG , Guoqing ZHAO , Qijun ZHAO , Li MA . High⁃precision simulation of aeroelastic characteristics of TEF rotor based on CFD/CSD coupling[J]. ACTA AERONAUTICAET ASTRONAUTICA SINICA, 2024 , 45(18) : 229904 -229904 . DOI: 10.7527/S1000-6893.2023.29904

References

1 SHERIDAN P F, SMITH R P. Interactional aerodynamics:A new challenge to helicopter technology[J]. Journal of the American Helicopter Society198025(1): 3-21.
2 GU Z Q. Study of control concept of adaptive rotor for vibration control: DLR 131-96/34.14S[R]. Braunschweig: DLR, 1996: 1-14.
3 ROTH D, ENENKL B, DIETERICH O. Active rotor control by flaps for vibration reduction: Full scale demonstrator and first flight test results[C]∥ 32nd European Rotorcraft Forum. Red Hook: Curran Associates Inc., 2007: 801-814.
4 MILGRAM J, CHOPRA I, STRAUB F. Rotors with trailing edge flaps: Analysis and comparison with experimental data[J]. Journal of the American Helicopter Society199843(4): 319-332.
5 FRIEDMANN P P, DE TERLIZZI M, MYRTLE T F. New developments in vibration reduction with actively controlled trailing edge flaps[J]. Mathematical and Computer Modelling200133(10/11): 1055-1083.
6 SHEN J W, CHOPRA I. Swashplateless helicopter rotor with trailing-edge flaps[J]. Journal of Aircraft200441(2): 208-214.
7 LIM I G, LEE I. Aeroelastic analysis of rotor systems using trailing edge flaps[J]. Journal of Sound and Vibration2009321(3/4/5): 525-536.
8 DALLI U, YüKSEL ?. Identification of flap motion parameters for vibration reduction in helicopter rotors with multiple active trailing edge flaps[J]. Shock and Vibration201118(5): 727-745.
9 GENNARETTI M, BERNARDINI G, SERAFINI J, et al. Helicopter vibratory loads alleviation through combined action of trailing-edge flap and variable-stiffness devices[J]. International Journal of Aerospace Engineering20152015: 485964.
10 JAIN R, YEO H, CHOPRA I. Computational fluid dynamics: Computational structural dynamics analysis of active control of helicopter rotor for performance improvement[J]. Journal of the American Helicopter Society201055(4): 042004.
11 王荣, 夏品奇. 多片后缘小翼对直升机旋翼桨叶动态失速及桨毂振动载荷的控制[J]. 航空学报201334(5): 1083-1091.
  WANG R, XIA P Q. Control of helicopter rotor blade dynamic stall and hub vibration loads by multiple trailing edge flaps[J]. Acta Aeronautica et Astronautica Sinica201334(5): 1083-1091 (in Chinese).
12 LIU S M, YANG W D, WU J. Study on vibratory loads of rotor with trailing edge excitation[J]. Advanced Materials Research20141044/1045: 877-880.
13 周桓. 基于双后缘小翼的智能旋翼振动抑制及实现研究[D]. 南京: 南京航空航天大学, 2020: 29-35.
  ZHOU H. Research on vibration suppression and realization of smart rotor based on dual trailing-edge flaps[D]. Nanjing: Nanjing University of Aeronautics and Astronautics, 2020: 29-35 (in Chinese).
14 SU T Y, LU Y, MA J C, et al. Aerodynamic characteristics analysis of electrically controlled rotor based on viscous vortex particle method[J]. Aerospace Science and Technology202097: 105645.
15 SHEN J W, CHOPRA I. Aeroelastic stability of trailing-edge flap helicopter rotors[J]. Journal of the American Helicopter Society200348(4): 236-243.
16 刘士明, 杨卫东, 虞志浩, 等. 后缘小翼智能旋翼减振效果影响因素分析[J]. 振动与冲击201736(3): 138-144.
  LIU S M, YANG W D, YU Z H, et al. Influence factors analysis for smart vibration control of a rotor wing with trailing edge flaps[J]. Journal of Vibration and Shock201736(3): 138-144 (in Chinese).
17 关晓辉, 李占科, 宋笔锋. CST气动外形参数化方法研究[J]. 航空学报201233(4): 625-633.
  GUAN X H, LI Z K, SONG B F. A study on CST aerodynamic shape parameterization method[J]. Acta Aeronautica et Astronautica Sinica201233(4): 625-633 (in Chinese).
18 马奕扬, 招启军, 赵国庆. 基于后缘小翼的旋翼翼型动态失速控制分析[J]. 航空学报201738(3): 120312.
  MA Y Y, ZHAO Q J, ZHAO G Q. Dynamic stall control of rotor airfoil via trailing-edge flap[J]. Acta Aeronautica et Astronautica Sinica201738(3): 120312 (in Chinese).
19 马奕扬, 招启军. 后缘小翼对旋翼气动特性的控制机理及参数分析[J]. 航空学报201839(5): 121671.
  MA Y Y, ZHAO Q J. Control mechanism and parameter analyses of aerodynamic characteristics of rotor via trailing-edge flap[J]. Acta Aeronautica et Astronautica Sinica201839(5): 121671 (in Chinese).
20 招启军, 徐国华. 直升机计算流体动力学基础[M]. 北京: 科学出版社, 2016: 62-67.
  ZHAO Q J, XU G H. Foundations of helicopter computational fluid dynamics[M]. Beijing: Science Press, 2016: 62-67 (in Chinese).
21 ZHAO Q J, ZHAO G Q, WANG B, et al. Robust Navier-Stokes method for predicting unsteady flowfield and aerodynamic characteristics of helicopter rotor[J]. Chinese Journal of Aeronautics201831(2): 214-224.
22 周金龙, 董凌华, 杨卫东, 等. 基于加权最小二乘法辨识的后缘襟翼智能旋翼振动载荷闭环控制仿真研究[J]. 振动与冲击201938(4): 237-244.
  ZHOU J L, DONG L H, YANG W D, et al. Closed-loop vibration control simulation of a helicopter active rotor with trailing-edge flaps based on the weighted-least-squares-error identification method[J]. Journal of Vibration and Shock201938(4): 237-244 (in Chinese).
23 ZHOU Z X, HUANG X C, TIAN J J, et al. Numerical and experimental analysis on the helicopter rotor dynamic load controlled by the actively trailing edge flap[J]. Smart Material Structures202231(3): 035023.
24 周子宣, 田嘉劲, 唐敏, 等. 主动后缘襟翼对旋翼桨毂振动载荷控制的机理与风洞试验[J]. 机械工程学报202359(14): 254-263.
  ZHOU Z X, TIAN J J, TANG M, et al. Mechanism and wind tunnel experiment of active controlled flap on vibration load control of rotor hub[J]. Journal of Mechanical Engineering202359(14): 254-263 (in Chinese).
25 YUAN K A, FRIEDMANN P P. Aeroelasticity and structural optimization of composite helicopter rotor blades with swept tips: NASA-CR-4665[R]. Washington, D.C.: NASA, 1995.
26 ZHANG X Y, WANG H L, ZHAO Q J, et al. Structural modeling and dynamic analysis of the two-segment deployable beam system[J]. International Journal of Mechanical Sciences2022233: 107633.
27 ZHANG X Y, CHEN X, ZHANG K, et al. Structural modeling and modal analysis of rotor blade during ice accretion[J]. Aerospace Science and Technology2022123: 107448.
28 NEWMARK N M. A method of computation for structural dynamics[J]. Journal of the Engineering Mechanics Division195985(3): 67-94.
29 赵蒙蒙. 基于CFD/CSD耦合方法的复合材料旋翼结构载荷优化分析[D]. 南京: 南京航空航天大学, 2017: 12-13.
  ZHAO M M. Optimization analyses on structural load of composite rotor based on CFD/CSD coupling method[D]. Nanjing: Nanjing University of Aeronautics and Astronautics, 2017: 12-13 (in Chinese).
30 HEFFERNAN R M, GAUBERT M. Structural and aerodynamic loads and performance measurements of an SA349/2 helicopter with an advanced geometry rotor: NASA-TM-88370[R]. Washington, D. C.: NASA, 1986.
31 马砾, 招启军, 赵蒙蒙, 等. 基于CFD/CSD耦合方法的旋翼气动弹性载荷计算分析[J]. 航空学报201738(6): 120762.
  MA L, ZHAO Q J, ZHAO M M, et al. Computation analyses of aeroelastic loads of rotor based on CFD/CSD coupling method[J]. Acta Aeronautica et Astronautica Sinica201738(6): 120762 (in Chinese).
32 王松. 基于CFD/CSD松耦合的直升机稳态飞行状态配平与载荷预估[D]. 南京: 南京航空航天大学, 2019: 76-77.
  WANG S. Trim and load estimation of steady flight state of helicopter based on CFD/CSD loose coupling [D]. Nanjing: Nanjing University of Aeronautics and Astronautics,2019:76-77 (in Chinese).
33 ANANTHAN S, BAEDER J, SIM B W, et al. Predic-tion and validation of the aerodynamics, structure dynamics, and acoustics of the SMART rotor using a loosely-coupled CFD-CSD analysis[C]∥ 66th Annual Forum and Technology Display of the American Helicopter Society International. Alexandria: The AHS International Inc., 2010: 2031-2057.
34 HASSAN A A, STRAUB F K, NOONAN K W. Experimental/numerical evaluation of integral trailing edge flaps for helicopter rotor applications[J]. Journal of the American Helicopter Society200550(1): 3-17.
35 FULTON M V, ORMISTON R A. Hover testing of a small-scale rotor with on-blade elevons[J]. Journal of the American Helicopter Society200146(2): 96-106.
36 FULTON M V, ORMISTON R A. Small-scale rotor experiments with on-blade elevons to reduce blade vibratory loads in forward flight[C]∥ American Helicopter Society 54th Annual Forum. Washington, D. C.: The AHS International Inc., 1998: 1-18.
37 刘士明. 带后缘小翼的智能旋翼振动载荷抑制研究[D]. 南京: 南京航空航天大学, 2016: 59-63.
  LIU S M. Research on vibratory load control of smart rotor with trailing edge flaps[D]. Nanjing: Nanjing University of Aeronautics and Astronautics, 2016: 59-63 (in Chinese).
38 刘士明, 杨卫东, 虞志浩, 等. 带后缘小翼的旋翼振动载荷计算[J]. 航空动力学报201631(6): 1496-1503.
  LIU S M, YANG W D, YU Z H, et al. Vibratory loads prediction of rotor with trailing edge flaps[J]. Journal of Aerospace Power201631(6): 1496-1503 (in Chinese).
Outlines

/