大型灭火飞机投水过程数值仿真方法研究
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摘要
基于低速气流下的水体扩散特性,建立了大型灭火飞机投水过程的数值模型。根据水体在空中破裂各个阶段的物理状态和受力情况,综合国内外水体在不同量级下计算的数学模型,采用滑移结构网格技术,给出了适用于水体从水箱投放到落地整个过程的欧拉模型,用于飞机投水后的着水特性分析,并通过与国外风洞试验结果的对比,验证了模型的正确性。数值模拟结果表明,欧拉模型的建立有效地解决了腹箱式灭火飞机投水效能评估的问题,为飞行试验和工程设计提供了有益的理论依据。
Based on the characteristics of water diffusion at low velocity, a numerical model of water-dropping process for large fire-extinguishing aircraft is built. According to the physical state and force situation of water body in each stage of air rupture, by combining the mathematical model of water body both at home and abroad calculated at different orders of magnitude, and adopting the sliding structure mesh technique, an Euler model suitable for the whole process of water body from water tank to the ground was presented, which can be used for analysis of the water touching characteristics of aircraft. And also, the correctness of the model is verified by comparing the results with the results of wind tunnel experiments abroad. The numerical simulation results show that the establishment of Euler model can effectively solve the problem of evaluating the water-dropping efficiency of the ventral box fire extinguishing aircraft and provide a useful theoretical basis for the flight test and engineering design.
Based on the characteristics of water diffusion at low velocity, a numerical model of water-dropping process for large fire-extinguishing aircraft is built. According to the physical state and force situation of water body in each stage of air rupture, by combining the mathematical model of water body both at home and abroad calculated at different orders of magnitude, and adopting the sliding structure mesh technique, an Euler model suitable for the whole process of water body from water tank to the ground was presented, which can be used for analysis of the water touching characteristics of aircraft. And also, the correctness of the model is verified by comparing the results with the results of wind tunnel experiments abroad. The numerical simulation results show that the establishment of Euler model can effectively solve the problem of evaluating the water-dropping efficiency of the ventral box fire extinguishing aircraft and provide a useful theoretical basis for the flight test and engineering design.
引文
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[7] 姚震球,高慧,杨春蕾.基于滑移网格的带螺旋桨艇体尾流场数值分析方法[J].江苏科技大学学报(自然科学版),2008,22(2):15-20.
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[9] 温正.FLUENT流体计算应用教程[M].北京:清华大学出版社,2013:165-184.
[10] Amorim J H.Numerical modelling of the aerial drop of firefighting agents by fixed-wing aircraft.Part I:model development[J].International Journal of Wildland Fire,2011,20(3):384-393.
[2] Ramirez Y P,Gould J,Ferrer E P,et al.Computing aerial suppression effectiveness by IR monitoring[J].Fire Safety Journal,2009,46(112):2-8.
[3] Plucinski M P,Gould J S,Mccarthy G,et al.The effectiveness and efficiency of aerial firefighting in Australia[M].Melbourne:Australian Government’s Cooperative Research Centre Programme,2007.
[4] 王永亮.大型灭火飞机投水算法研究[D].南昌:南昌航空大学,2012.
[5] Satoh K,Maeda I,Kuwahara K,et al.A numerical study of water dump in aerial fire fighting[J].Fire Safety Science,2005,8(8):777-787.
[6] Amorim J H,Borrego C,Miranda A I.An operational dropping model towards efficient aerial firefighting[J].Monitoring and Management of Forest Firefighting,2008,65(2):51-60.
[7] 姚震球,高慧,杨春蕾.基于滑移网格的带螺旋桨艇体尾流场数值分析方法[J].江苏科技大学学报(自然科学版),2008,22(2):15-20.
[8] 张志荣,李百齐,赵峰.螺旋桨/船体粘性流场的整体数值求解[J].船舶力学,2004,8(5):19-26.
[9] 温正.FLUENT流体计算应用教程[M].北京:清华大学出版社,2013:165-184.
[10] Amorim J H.Numerical modelling of the aerial drop of firefighting agents by fixed-wing aircraft.Part I:model development[J].International Journal of Wildland Fire,2011,20(3):384-393.