单旋翼植保无人机翼尖涡流对雾滴飘移的影响
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摘要
为研究单旋翼植保无人机翼尖涡流对雾滴飘移的影响特性,基于格子玻尔兹曼(Lattice-Boltzman,LBM)方法的自适应细化物理模型,对单旋翼无人机的旋翼流场进行了数值模拟。通过改变无人机喷杆的垂直距离和喷头在旋翼下方的位置,研究了不同飞行速度下,无人机翼尖涡流对雾滴飘移的影响规律。为捕获到不同粒径的雾滴在无人机下洗流场中的运动轨迹,采用基于拉格朗日离散相粒子跟踪法模拟了雾滴的运动轨迹。为验证数值模拟的准确性,进行了试验验证,研究结果表明:当无人机飞行速度大于3 m/s时,机身后方开始出现螺旋型尾涡,且飞行速度越大、飞行高度越高,尾涡向机身后方的扩散距离越远;当飞行速度为5 m/s、飞行高度为3 m时,38%的雾滴因螺旋尾涡而造成空中飘移,其中粒径小于100μm的雾滴约占总飘移雾滴数的80%;喷杆距离主旋翼的高度对雾滴因翼尖涡流造成的飘移影响不明显,但喷头的位置越靠近主旋翼的边缘,雾滴越容易被翼尖涡流卷吸。
Plant protection drone has great application prospects in agricultural production due to its low working height,flexible operation,good adaptability to terrain,slight environmental pollution and high efficiency in pest control. However,it could cause secondary disasters with droplets drift due to wingtip vortices. To investigate the effect of wing tip vortex flow of a single-rotor unmanned aerial vehicle on droplet drift, the flow field under a single-rotor unmanned aerial vehicle(UAV) was simulated numerically based on an adaptive thinned physical model of the lattice-Boltzman(LBM) method. The drift characteristics at different flight speeds of the wingtip vortex were examined for various nozzle positions and vertical distances between different spray booms. The Lagrange discrete particle tracking method was applied to capture accurately the trajectories of droplets with different particle diameters.Spray tests were conducted to verify the accuracy of the numerical simulation. It was shown that as the UAV flight speed was greater than 3 m/s,a spiral tail vortex appeared at the rear of the fuselage. The range of the tail vortex behind the fuselage became longer as the flight speed or flight altitude got higher.And 38% of the droplets was drifted by the spiral tail vortex at the flight speed of 5 m/s and the flight height of 3 m,in which 80% of the drifted droplets was smaller than 100 μm. The distance between the sprayer and the main rotor had little effect on the drop drift caused by the wingtip vortex. While thenozzle was closer to the edge of the main rotor,the droplets can be more easily sucked by the wingtip vortex.
Plant protection drone has great application prospects in agricultural production due to its low working height,flexible operation,good adaptability to terrain,slight environmental pollution and high efficiency in pest control. However,it could cause secondary disasters with droplets drift due to wingtip vortices. To investigate the effect of wing tip vortex flow of a single-rotor unmanned aerial vehicle on droplet drift, the flow field under a single-rotor unmanned aerial vehicle(UAV) was simulated numerically based on an adaptive thinned physical model of the lattice-Boltzman(LBM) method. The drift characteristics at different flight speeds of the wingtip vortex were examined for various nozzle positions and vertical distances between different spray booms. The Lagrange discrete particle tracking method was applied to capture accurately the trajectories of droplets with different particle diameters.Spray tests were conducted to verify the accuracy of the numerical simulation. It was shown that as the UAV flight speed was greater than 3 m/s,a spiral tail vortex appeared at the rear of the fuselage. The range of the tail vortex behind the fuselage became longer as the flight speed or flight altitude got higher.And 38% of the droplets was drifted by the spiral tail vortex at the flight speed of 5 m/s and the flight height of 3 m,in which 80% of the drifted droplets was smaller than 100 μm. The distance between the sprayer and the main rotor had little effect on the drop drift caused by the wingtip vortex. While thenozzle was closer to the edge of the main rotor,the droplets can be more easily sucked by the wingtip vortex.
引文
1张东彦,兰玉彬,陈立平,等.中国农业航空施药技术研究进展与展望[J/OL].农业机械学报,2014,45(10):53-59.http:∥www.jcsam.org/jcsam/ch/reader/view_abstract.aspx?flag=1&file_no=20141009&journal_id=jcsam.DOI:10.6041/j.issn.1000-1298.2014.10.009.ZHANG Dongyan,LAN Yubin,CHEN Liping,et al.Status and future trends of agricultural aerial spraying technology in China[J/OL].Transactions of the Chinese Society for Agricultural Machinery,2014,45(10):53-59.(in Chinese)
2 XIONGKUI H,BONDS J,HERBST A,et al.Recent development of unmanned aerial vehicle for plant protection in East Asia[J].International Journal of Agricultural and Biological Engineering,2017,10(3):18-30.
3周志艳,臧英,罗锡文,等.中国农业航空植保产业技术创新发展战略[J].农业工程学报,2013,29(24):1-10.ZHOU Zhiyan,ZANG Ying,LUO Xiwen,et al.Technology innovation development strategy on agricultural aviation industry for plant protection in China[J].Transactions of the CSAE,2013,29(24):1-10.(in Chinese)
4文晟,兰玉彬,张建桃,等.农用无人机超低容量旋流喷嘴的雾化特性分析与试验[J].农业工程学报,2016,32(20):85-93.WEN Sheng,LAN Yubin,ZHANG Jiantao,et al.Analysis and experiment on atomization characteristics of ultra-low-volume swirl nozzle for agricultural unmanned aviation vehicle[J].Transactions of the CSAE,2016,32(20):85-93.(in Chinese)
5周志艳,明锐,臧禹,等.中国农业航空发展现状及对策建议[J].农业工程学报,2017,33(20):1-13.ZHOU Zhiyan,MING Rui,ZANG Yu,et al.Development status and countermeasures of agricultural aviation in China[J].Transactions of the CSAE,2017,33(20):1-13.(in Chinese)
6 SONGCHAO Z,XINYU X,ZHU S,et al.Downwash distribution of single-rotor unmanned agricultural helicopter on hovering state[J].International Journal of Agricultural and Biological Engineering,2017,10(5):14-24.
7张宋超,薛新宇,秦维彩,等.N-3型农用无人直升机航空施药飘移模拟与试验[J].农业工程学报,2015,31(3):87-93.ZHANG Songchao,XUE Xinyu,QIN Weicai,et al.Simulation and experimental verification of aerial spraying drift on N-3unmanned spraying helicopter[J].Transactions of the CSAE,2015,31(3):87-93.(in Chinese)
8王军锋,徐文彬,闻建龙,等.大载荷植保无人直升机喷雾气液两相流动数值模拟[J/OL].农业机械学报,2017,48(9):62-69.http:∥www.jcsam.org/jcsam/ch/reader/view_abstract.aspx?flag=1&file_no=20170908&journal_id=jcsam.DOI:10.6041/j.issn.1000-1298.2017.09.008.WANG Junfeng,XU Wenbin,WEN Jianlong,et al.Numerical simulation on gas-liquid phase flow of large-scale plant protection unmanned aerial vehicle spraying[J/OL].Transactions of the Chinese Society for Agricultural Machinery,2017,48(9):62-69.(in Chinese)
9杨知伦,葛鲁振,祁力钧,等.植保无人机旋翼下洗气流对喷幅的影响研究[J/OL].农业机械学报,2018,49(1):116-122.http:∥www.j-csam.org/jcsam/ch/reader/view_abstract.aspx?flag=1&file_no=20180114&journal_id=jcsam.DOI:10.6041/j.issn.1000-1298.2018.01.014.YANG Zhilun,GE Luzhen,QI Lijun,et al.Influence of UAV rotor down-wash airflow on spray width[J/OL].Transactions of the Chinese Society for Agricultural Machinery,2018,49(1):116-122.(in Chinese)
10 BAE Y,KOO Y M.Flight attitudes and spray patterns of a roll-balanced agricultural unmanned helicopter[J].Applied Engineering in Agriculture,2013,29(5):675-682.
11 ZHANG B,TANG Q,CHEN L,et al.Numerical simulation of wake vortices of crop spraying aircraft close to the ground[J].Biosystems Engineering,2016,145:52-64.
12叶舟,徐国华,史勇杰.旋翼桨尖涡生成及演化机理的高精度数值研究[J].航空学报,2017,38(7):43-53.YE Zhou,XU Guohua,SHI Yongjie.High-resolution numerical research on formation and evolution mechanism of rotor blade tip vortex[J].Acta Aeronauticaet Astronautica Sinica,2017,38(7):43-53.(in Chinese)
13 MNASRI C,HAFSIA Z,OMRI M,et al.A moving grid model for simulation of free surface behavior induced by horizontal cylinders exit and entry[J].Engineering Applications of Computational Fluid Mechanics,2010,4(2):260-275.
14 MARGOT X,HOYAS S,FAJARDO P,et al.A moving mesh generation strategy for solving an injector internal flow problem[J].Mathematical&Computer Modelling,2010,52(7):1143-1150.
15 SRIKANTH C,BHASKER C.Flow analysis in valve with moving grids through CFD techniques[J].Advances in Engineering Software,2009,40(3):193-201.
16 SONG X,CUI L,CAO M,et al.A CFD analysis of the dynamics of a direct-operated safety relief valve mounted on a pressure vessel[J].Energy Conversion&Management,2014,81(2):407-419.
17 SHANGGUAN Y,WANG X,LI Y.Large-scaled simulation on the coherent vortex evolution of a jet in a cross-flow based on lattice Boltzmann method[J].Thermal Science,2015,19(3):977-988.
18 MIGUEL A F.Non-Darcy porous media flow in no-slip and slip regimes[J].Thermal Science,2012,16(1):167-176.
19 JOURABIAN M,FARHADI M,RABIENATAJ D A A,et al.Lattice Boltzmann simulation of melting phenomenon with natural convection from an eccentric annulus[J].Thermal Science,2013,17(3):877-890.
20 ALKSHAISH J A,ESFAHANI J A.Lattice Boltzmann simulation of turbulent natural convection:enclosure heated from below[J].Journal of Thermophysics&Heat Transfer,2017,31(4):1-10.
21 CAO N,CHEN S,JIN S,et al.Physical symmetry and lattice symmetry in the lattice Boltzmann method[J].Physical Review EStatistical Physics Plasmas Fluids&Related Interdisciplinary Topics,1997,55(1):21-24.
22 MEN Y,LAI Y,DONG S,et al.Research on CO dispersion of a vehicular exhaust plume using lattice Boltzmann method and large eddy simulation[J].Transportation Research Part D:Transport and Environment,2017,52:202-214.
23 BHAGWAT M J,LEISHMAN J G.Correlation of helicopter rotor tip vortex measurements[J].AIAA Journal,2000,38(2):301-308.
24 RAMASAMY M,LEISHMAN J G.Benchmarking particle image velocimetry with laser doppler velocimetry for rotor wake measurements[J].AIAA Journal,2007,45(11):2622-2633.
25 BAUKNECHT A,EWERS B,SCHNEIDER O,et al.Blade tip vortex measurements on actively twisted rotor blades[J].Experiments in Fluids,2017,58(5):49-64.
26 BAUKNECHT A,MERZ C B,RAFFEL M,et al.Blade-tip vortex detection in maneuvering flight using the background-oriented schlieren technique[J].Journal of Aircraft,2014(6):1-13.
27魏鹏,史勇杰,徐国华.复杂旋翼流场的耦合欧拉-拉格朗日数值方法[J].航空学报,2013,34(7):1538-1547.WEI Peng,SHI Yongjie,XU Guohua.Coupled Eulerian-Lagrangian method for complicated rotor flow field prediction[J].Acta Aeronauticaet Astronautica Sinica,2013,34(7):1538-1547.(in Chinese)
28 DUGA A T,DELELE M A,RUYSEN K,et al.Development and validation of a 3D CFD model of drift and its application to airassisted orchard sprayers[J].Biosystems Engineering,2017,154:62-75.
29 HILZ E,VERMEER A W P.Spray drift review:the extent to which a formulation can contribute to spray drift reduction[J].Crop Protection,2013,44(1):75-83.
30中国民用航空总局运输管理司.飞机喷雾飘移现场测量方法:MH/T 1050-2012[S].北京:中国民用航空局,2012.
31中国民用航空总局运输管理司.农业航空作业质量技术指标:MH/T 1002-1995[S].北京:中国民用航空局,1995.
2 XIONGKUI H,BONDS J,HERBST A,et al.Recent development of unmanned aerial vehicle for plant protection in East Asia[J].International Journal of Agricultural and Biological Engineering,2017,10(3):18-30.
3周志艳,臧英,罗锡文,等.中国农业航空植保产业技术创新发展战略[J].农业工程学报,2013,29(24):1-10.ZHOU Zhiyan,ZANG Ying,LUO Xiwen,et al.Technology innovation development strategy on agricultural aviation industry for plant protection in China[J].Transactions of the CSAE,2013,29(24):1-10.(in Chinese)
4文晟,兰玉彬,张建桃,等.农用无人机超低容量旋流喷嘴的雾化特性分析与试验[J].农业工程学报,2016,32(20):85-93.WEN Sheng,LAN Yubin,ZHANG Jiantao,et al.Analysis and experiment on atomization characteristics of ultra-low-volume swirl nozzle for agricultural unmanned aviation vehicle[J].Transactions of the CSAE,2016,32(20):85-93.(in Chinese)
5周志艳,明锐,臧禹,等.中国农业航空发展现状及对策建议[J].农业工程学报,2017,33(20):1-13.ZHOU Zhiyan,MING Rui,ZANG Yu,et al.Development status and countermeasures of agricultural aviation in China[J].Transactions of the CSAE,2017,33(20):1-13.(in Chinese)
6 SONGCHAO Z,XINYU X,ZHU S,et al.Downwash distribution of single-rotor unmanned agricultural helicopter on hovering state[J].International Journal of Agricultural and Biological Engineering,2017,10(5):14-24.
7张宋超,薛新宇,秦维彩,等.N-3型农用无人直升机航空施药飘移模拟与试验[J].农业工程学报,2015,31(3):87-93.ZHANG Songchao,XUE Xinyu,QIN Weicai,et al.Simulation and experimental verification of aerial spraying drift on N-3unmanned spraying helicopter[J].Transactions of the CSAE,2015,31(3):87-93.(in Chinese)
8王军锋,徐文彬,闻建龙,等.大载荷植保无人直升机喷雾气液两相流动数值模拟[J/OL].农业机械学报,2017,48(9):62-69.http:∥www.jcsam.org/jcsam/ch/reader/view_abstract.aspx?flag=1&file_no=20170908&journal_id=jcsam.DOI:10.6041/j.issn.1000-1298.2017.09.008.WANG Junfeng,XU Wenbin,WEN Jianlong,et al.Numerical simulation on gas-liquid phase flow of large-scale plant protection unmanned aerial vehicle spraying[J/OL].Transactions of the Chinese Society for Agricultural Machinery,2017,48(9):62-69.(in Chinese)
9杨知伦,葛鲁振,祁力钧,等.植保无人机旋翼下洗气流对喷幅的影响研究[J/OL].农业机械学报,2018,49(1):116-122.http:∥www.j-csam.org/jcsam/ch/reader/view_abstract.aspx?flag=1&file_no=20180114&journal_id=jcsam.DOI:10.6041/j.issn.1000-1298.2018.01.014.YANG Zhilun,GE Luzhen,QI Lijun,et al.Influence of UAV rotor down-wash airflow on spray width[J/OL].Transactions of the Chinese Society for Agricultural Machinery,2018,49(1):116-122.(in Chinese)
10 BAE Y,KOO Y M.Flight attitudes and spray patterns of a roll-balanced agricultural unmanned helicopter[J].Applied Engineering in Agriculture,2013,29(5):675-682.
11 ZHANG B,TANG Q,CHEN L,et al.Numerical simulation of wake vortices of crop spraying aircraft close to the ground[J].Biosystems Engineering,2016,145:52-64.
12叶舟,徐国华,史勇杰.旋翼桨尖涡生成及演化机理的高精度数值研究[J].航空学报,2017,38(7):43-53.YE Zhou,XU Guohua,SHI Yongjie.High-resolution numerical research on formation and evolution mechanism of rotor blade tip vortex[J].Acta Aeronauticaet Astronautica Sinica,2017,38(7):43-53.(in Chinese)
13 MNASRI C,HAFSIA Z,OMRI M,et al.A moving grid model for simulation of free surface behavior induced by horizontal cylinders exit and entry[J].Engineering Applications of Computational Fluid Mechanics,2010,4(2):260-275.
14 MARGOT X,HOYAS S,FAJARDO P,et al.A moving mesh generation strategy for solving an injector internal flow problem[J].Mathematical&Computer Modelling,2010,52(7):1143-1150.
15 SRIKANTH C,BHASKER C.Flow analysis in valve with moving grids through CFD techniques[J].Advances in Engineering Software,2009,40(3):193-201.
16 SONG X,CUI L,CAO M,et al.A CFD analysis of the dynamics of a direct-operated safety relief valve mounted on a pressure vessel[J].Energy Conversion&Management,2014,81(2):407-419.
17 SHANGGUAN Y,WANG X,LI Y.Large-scaled simulation on the coherent vortex evolution of a jet in a cross-flow based on lattice Boltzmann method[J].Thermal Science,2015,19(3):977-988.
18 MIGUEL A F.Non-Darcy porous media flow in no-slip and slip regimes[J].Thermal Science,2012,16(1):167-176.
19 JOURABIAN M,FARHADI M,RABIENATAJ D A A,et al.Lattice Boltzmann simulation of melting phenomenon with natural convection from an eccentric annulus[J].Thermal Science,2013,17(3):877-890.
20 ALKSHAISH J A,ESFAHANI J A.Lattice Boltzmann simulation of turbulent natural convection:enclosure heated from below[J].Journal of Thermophysics&Heat Transfer,2017,31(4):1-10.
21 CAO N,CHEN S,JIN S,et al.Physical symmetry and lattice symmetry in the lattice Boltzmann method[J].Physical Review EStatistical Physics Plasmas Fluids&Related Interdisciplinary Topics,1997,55(1):21-24.
22 MEN Y,LAI Y,DONG S,et al.Research on CO dispersion of a vehicular exhaust plume using lattice Boltzmann method and large eddy simulation[J].Transportation Research Part D:Transport and Environment,2017,52:202-214.
23 BHAGWAT M J,LEISHMAN J G.Correlation of helicopter rotor tip vortex measurements[J].AIAA Journal,2000,38(2):301-308.
24 RAMASAMY M,LEISHMAN J G.Benchmarking particle image velocimetry with laser doppler velocimetry for rotor wake measurements[J].AIAA Journal,2007,45(11):2622-2633.
25 BAUKNECHT A,EWERS B,SCHNEIDER O,et al.Blade tip vortex measurements on actively twisted rotor blades[J].Experiments in Fluids,2017,58(5):49-64.
26 BAUKNECHT A,MERZ C B,RAFFEL M,et al.Blade-tip vortex detection in maneuvering flight using the background-oriented schlieren technique[J].Journal of Aircraft,2014(6):1-13.
27魏鹏,史勇杰,徐国华.复杂旋翼流场的耦合欧拉-拉格朗日数值方法[J].航空学报,2013,34(7):1538-1547.WEI Peng,SHI Yongjie,XU Guohua.Coupled Eulerian-Lagrangian method for complicated rotor flow field prediction[J].Acta Aeronauticaet Astronautica Sinica,2013,34(7):1538-1547.(in Chinese)
28 DUGA A T,DELELE M A,RUYSEN K,et al.Development and validation of a 3D CFD model of drift and its application to airassisted orchard sprayers[J].Biosystems Engineering,2017,154:62-75.
29 HILZ E,VERMEER A W P.Spray drift review:the extent to which a formulation can contribute to spray drift reduction[J].Crop Protection,2013,44(1):75-83.
30中国民用航空总局运输管理司.飞机喷雾飘移现场测量方法:MH/T 1050-2012[S].北京:中国民用航空局,2012.
31中国民用航空总局运输管理司.农业航空作业质量技术指标:MH/T 1002-1995[S].北京:中国民用航空局,1995.