Experiment on flow mechanism and aerodynamic interaction characteristics of tilt-rotor aircraft
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摘要: 采用试验方法测量了悬停和过渡状态倾转旋翼机旋翼/机翼气动干扰特性,部分揭示了干扰流动的机理。基于3D-PIV(particle image velocimetry)技术的流场测量结果,发现大总距状态相对于小总距时倾转旋翼下洗流收缩更为剧烈,并有更强烈的卷起涡;揭示了“喷泉效应”的产生机理,受旋翼诱导作用的影响,“喷泉”中心的位置会随着总距和间距的改变而发生显著变化。测量了不同构型及状态参数对倾转旋翼/机翼之间气动干扰影响,发现减小垂直或水平距离均可使倾转旋翼升力有所增大,但将会增加机翼受到的旋翼下洗载荷。进行了该构型过渡状态气动干扰特性试验,获得旋翼、机翼综合气动特性与机翼攻角之间的影响关系,在较大机翼攻角时,将会加强对旋翼下洗流的阻碍作用,对旋翼起到类似“地面效应”的增升效果,但该现象随着机翼的偏转不断削弱;机翼升力随机翼段攻角增加呈现出先增大后减小的趋势。Abstract: With use of experimental methods, aerodynamic interactional characteristics between rotor and wing of a tilt-rotor aircraft were measured both in hover and transition modes, partly revealing the interactional flow mechanism. The shrinking of rotor downwash was found to be more intense and roll-up vortex was more severe, in its large collective pitch states compared with the small one, based on the result of flow measurement via 3D-PIV (particle image velocimetry) technology. The generation mechanism of “fountain effect” was revealed and the position of “fountain” center influenced by the induced effect of rotor, varied visibly with the changes of collective pitch and the interval between rotor and wing. Then the aerodynamic interactions between rotor and wing in different configurations and state parameters were measured, and during the measurement, tilt-rotors lift was found to be increased either by reducing the vertical or horizontal distances of wind and rotor, bringing to wing the increasing downloads at the same time. A particular configuration at last was selected to perform an interaction experiment in its transition mode to obtain the relationship between the comprehensive aerodynamic characteristics of wing, rotor and the angle of attack of the wing. It is shown that, in large angles of attack of the wing, the encumbering effect of the wing on rotor downwash, acting as a lift-promoting effect on the rotor like “ground effect”, is promoted, but this effect is enervating with the turning of the wing; and the wing lift tends to go up firstly then down with the increase of the wing angles of attack.
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[1] POLING D R,ROSENSTEIN H,RAJAGOPALAN G.Use of a Navier-Stokes code in understanding tiltrotor flowfields in hover[J].Journal of the American Helicopter Society,1998,43(2):103-109. [2] MAISEL M D,HARRIS D J.Hover tests of the XV-15 tiltrotor research aircraft[R].AIAA 81-2501,1981. [3] FELKER F F,SIGNOR D B,YOUNG L A.Performance and loads data from a hover test of a 0.658-scale V-22 rotor and wing[R].NASA-TM-89419,1987. [4] TADGHIGHI H,RAJAGOPALAN R G.A users manual for ROTTILT solver:tiltrotor fountain flow field prediction[R].NASA/CR-1999-208973,1999. [5] JOHNSON W.Airloads and wake geometry calculations for an isolated tiltrotor model in a wind tunnel[R].Moscow,Russian:27th European Rotorcraft Forum,2001. [6] RUITH M R.Unstructured,multiplex rotor source model with thrust and moment trimming-fluents VBM model[R].Toronto,Canada:23rd AIAA Applied Aerodynamics Conference,2005. [7] MCCLUER M S,JOHNSON J L.Full-span tiltrotor an aeroacoustic model “FS TRAM” overview and initial testing[R].San Francisco,US:American Helicopter Society Aerodynamics,Acoustics,and Test and Evaluations Technical Specialists Meeting,2002. [8] YOUNG L A,LILLIE D,MCCLUER M.Insights into airframe aerodynamics and rotor-on-wing interactions from a 0.25-scale tiltrotor wind tunnel model[R].San Francisco,US:American Helicopter Society Aerodynamics,Acoustics,and Test and Evaluations Technical Specialists Meeting,2002. [9] BURLEY C L,BROOKS T F,CHARLES B D.Tiltrotor aeroacoustic code (TRAC) prediction assessment and initial comparisons with TRAM test data[R].Rome,Italy:25th European Rotorcraft Forum,1999. [10] YAMAUCHI G K,JOHNSON W,WADCOCK A J.Vortex wake geometry of a model tiltrotor in forward flight[R].Tochigi,Japan:AHS International Meeting on Advanced Rotorcraft Technology and Lift Saving Activities,2002. [11] REDDY U C,KOMERATH N M.Whole-field velocity measurement for rotorcraft aerodynamic interactions[R].Montreal,Canada:55th Annual Forum of the American Helicopter Society,1999. [12] MATOS C,REDDY U,KOMERATH N.Rotor wake/fixed wing interactions with flap deflection[R].Montreal,Canada:55th American Helicopter Society Annual Forum,1999. [13] KOMERATH N,MATOS C,REDDY U.Flowfield issues related to tiltrotors[R].Arlington,US:Tiltrotor/Runway Independent Aircraft Technology and Applications Specialists Meeting of the American Helicopter Society,2001. [14] MEAKIN R L.Moving body overset grid methods for complete aircraft tiltrotor simulations[R].AIAA 93-3350,1993. [15] POTSDAM M A,STRAWN R C.CFD simulations of tiltrotor configurations in hover[J].Journal of the American Helicopter Society,2005,50(1):82-94. [16] 翁智勇,唐正飞,陈仁良.旋翼/机翼悬停状态气动干扰的试验研究[R].天津:第二十一届全国直升机年会,2005. [17] 李春华,徐国华.倾转旋翼机旋翼对机翼气动干扰研究[R].河北 保定:第二十二届全国直升机年会,2006. [18] 陈平剑,林永峰,黄水林.倾转旋翼机旋翼/机翼气动干扰的试验研究[J].直升机技术,2008(3):107-115.CHEN Pingjian,LIN Yongfeng,HUANG Shuilin.Experimental study on rotor/wing aerodynamic interaction for tilt-rotor aircraft[J].Helicopter Technique,2008(3):107-115.(in Chinese) [19] 李鹏,招启军.悬停状态倾转旋翼/机翼干扰流场及气动力的CFD计算[J].航空学报,2014,35(2):361-371.
LI Peng,ZHAO Qijun.CFD calculations on the interaction flowfield and aerodynamic force of tiltrotor/wing in hover[J].Acta Aeronautica et Astronautica Sinica,2014,35(2):361-371.(in Chinese)[20] LI Peng,ZHAO Qijun,ZHU Qiuxian.CFD calculations on the unsteady aerodynamic characteristics of a tilt-rotor in a conversion mode[J].Chinese Journal of Aeronautics,2015,28(6):1593-1605. [21] YE Liang,ZHANG Ying,YANG Shuo,et al.Numerical simulation of aerodynamic interaction for a tilt rotor aircraft in helicopter mode[J].Chinese Journal of Aeronautics,2016,29(4):843-854.
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