为了研究波浪情况下民机水上迫降性能，选用计算流体力学的有限体积法求解非定常不可压缩RANS方程，基于VOF法、整体动网格法、斯托克斯五阶波浪模型和自适应网格技术，以空客A320-200为研究对象，按照适航规章相关要求与建议，构建了民机水上迫降数值仿真模型。首先，对比分析了静水面和波浪水面下飞机水上迫降过程。结果表明：相同初始飞行参数下，波浪水面下最大水平过载为2.42G，是静水面的1.09倍；最大垂向过载为4.82G，是静水面的2.82倍。两种情况下，空气垫效应和潜水现象明显，碰撞初段，飞机均受到吸力作用；波浪情况下，跳跃现象出现，但并未对飞机的运动过程产生剧烈影响。其次，研究了波浪参数对水上迫降性能的影响。分析结果表明：同一波峰撞击阶段内，波高越高，则最大水平过载和最大垂向过载越大；波长越长，则最大垂向过载越小。波高越高，波长越长，则最大下沉速度越大。
To study the ditching performance of civil aircraft in wave conditions, The finite volume method of computational fluid dynamics is used to solve the unsteady incompressible RANS equation. Based on the relevant requirements and sugges-tions of airworthiness regulations, VOF method, whole dynamic grid method, stokes fifth-order wave model and adaptive grid technology are used to construct the numerical simulation model. The research object is airbus A320-200. Firstly, the ditching process of aircraft in the calm water and wave condition is compared and analyzed. The results show that the maximum horizontal overload is 2.42G in the wave condition, which is 1.09 times of that in the calm condition. The max-imum vertical overload is 4.82G, which is 2.82 times of that in the calm water condition. In both cases, cushion effect and diving phenomenon are obvious. In the initial stage of impact, the aircraft is affected by water suction. In the wave condi-tion, jumping phenomenon appears, but it does not have an apparent effect on the ditching process. Secondly, the influ-ence of wave factors on water ditching performance is studied. The results show that with the increase of the wave height, the maximum horizontal and vertical overload increase. With the increase of the wave length, the maximum vertical over-load decreases. With the increase of the wave height and length, the maximum sinking velocity increases.
[1]张苏. 水上迫降尾部吸能对飞机运动特性的影响[D]. 武汉理工大学, 2013.
ZHANG S. Effect of energy absorption of tail structure on the kinetic behavior during aircraft ditching[D]. Wuhan Uni-versity of Technology, 2013 (in Chinese).
[2]LINDENAU O. Rung T. Review of Transport Aircraft Ditch-ing Accidents[J].
[3]吴世德, 田彬. 民用飞机水上迫降适航验证程序的研究[J]. 民用飞机设计与研究, 2007(3):19-22
WU S D, TIAN B. Research on Airworthiness Verification Procedure for Civil Aircraft Ditching[J]. Civil Aircraft Design & Research, 2007(3):19-22 (in Chinese).
[4]PATEL A A. Greenwood Jr R P. Transport Water Impact and Ditching Performance[R]. GALAXY SCIENTIFIC CORP PLEASANTVILLE NJ, 1996.
[5]HUGHES K. Campbell J. Helicopter crashworthiness: A chronological review of research related to water impact from 1982 to 2006[J]. Journal of the American Helicopter Society, 2008, 53(4): 429-441.
[6]IBK J S, DE BLANPRé E, BERTRAND P, et al. D4. 5: Re-port on the impact of configurational changes on ditching loads and design risk mitigations[J]. 2019.
[7]PENTEC?TE N, VIGLIOTTI A. Crashworthiness of helicop-ters on water: Test and simulation of a full-scale WG30 im-pacting on water[J]. International journal of crashworthiness, 2003, 8(6): 559-572.
[8]HUGHES K. Application of improved Lagrangian tech-niques for helicopter crashworthiness on water[D]. Cranfield University, 2005.
[9]HUGHES K. Characterising the level of crashworthiness for impacts on hard ground and water surfaces for a metallic helicopter under floor structure: What lessons can be learned?[C]//Cranfield Multi-Strand Conference: Creating Wealth Through Research and Innovation. 2008, 6: 244.
[10]ALGUADICH S. Full scale crash test for cabin safety re-search[J]. Italian aerospace research center-(CIRA), 2000: 1-13.
[11]BENSCH L, SHIGUNOV V, BEUCK G, et al. Planned ditch-ing simulation of a transport airplane[C]//KRASH users seminar. 2001: 411-439.
[12]EADS CASA. CN235: Scaled Ditching Test. Shared Infor-mation within SMAES Program [R], Memoran-dum No ME-T-MM-110104, 2011.
[13]GOMES J B. Numerical Simulation of Aircraft Ditching of a Generic Transport Aircraft: Implementation of an Aerody-namic Model[D]. Instituto Superior Técnico, Portugal, 2015.
[14]GROENENBOOM P, CAMPBELL J, BENíTEZ MONTA?éS L, et al. Innovative SPH methods for aircraft ditching[J]. Proceedings of WCCM XI–ECCM V–ECFD VI, 2014: 4555-4566.
[15]CLIMENT H, BENITEZ L, ROSICH F, et al. Aircraft ditch-ing numerical simulation[C]//25th International congress of the aeronautical sciences. Hamburg, Germany, 2006: 1-16.
[16]ORTIZ R, PORTEMONT G, CHARLES J L, et al. Assesment of explicit FE capabilities for full scale coupled flu-id/structure aircraft ditching simulation [R]. OFFICE NATIONAL D ETUDES ET DE RECHERCHES AEROSPATIALES ONERA-PUBLICATIONS-TP, 2002, 167.
[17]WOODGATE M A, BARAKOS G N, SCRASE N, et al. Simu-lation of helicopter ditching using smoothed particle hydro-dynamics[J]. Aerospace Science and Technology, 2019, 85: 277-292.
[18]IBK J S, DE BLANPRé E, BERTRAND P, et al. D4. 5: Re-port on the impact of configurational changes on ditching loads and design risk mitigations[J]. 2019.
[19]CLIMENT H, ARéVALO F, VIANA J T, et al. DITCHING LOADS NUMERICAL AND EXPERIMENTAL ALTERNATIVES[J].
[20]HIRT C W, NICHOLS B D. Volume of fluid (VOF) method for the dynamics of free boundaries[J]. Journal of computa-tional physics, 1981, 39(1): 201-225.
[21]FENTON J. A fifth-order Stokes theory for steady waves[J]. Journal of Waterway, Port, Coastal and Ocean Engineering, 1985, 111(2): 216-234.
[22]AZCUETA R. Computation of turbulent free-surface flows around ships and floating bodies[J]. Technische Universitat, Hamburg-Harburg, Arbeitsbereiche Schiffbau, Germany, Published in Ship Technology Research, Volume 49, 2002, 2002
CJA