纵列式六旋翼大载荷无人机气动特性数值模拟及其优化研究

发布时间：2018-05-23 09:53

  本文选题：纵列式无人机 + 旋翼　； 参考：《吉林大学》2015年博士论文

【摘要】：当前,大载荷无人机技术仍属于国际前沿科技,只有美国、英国、加拿大、德国、法国等少数国家掌握,而我国起步较晚,尚处于研发阶段,这与国际先进水平的差距较大。因此,研制性能稳定、实用性强、可应用于航空物探领域的大载荷无人机是我国当前亟待解决的问题。纵列式无人机因具有较大的机身容积、较大的重心可变化范围以及较强的抗侧风能力等优点,在军事、民用两大领域都具有广阔的应用前景。但是,由于纵列式前、后旋翼之间存在一定的重叠区域,导致两旋翼之间存在相互的气动干扰,不能像单旋翼那样单独建模,而是需要耦合在一起加以考虑,这给旋翼流场和气动特性的计算增加了很大难度。为此,本文结合国家“863”计划项目-“重载荷智能化物探专用无人直升机研制”(2013AA063903),开展对纵列式六旋翼大载荷无人机旋翼系统流场特性和气动特性的研究工作。论文主要研究内容包括：(1)采用CFD方法对纵列式六旋翼大载荷无人机调节旋翼的悬停状态进行了数值模拟,并对其流场特性进行分析。通过对调节旋翼试验测量得出旋翼的基本气动特性,验证了数值模拟方法的有效性。在此基础上,对调节旋翼前飞状态下的气动特性进行分析,分别得出调节旋翼的升力、阻力和扭矩随前倾角、来流速度、旋翼转速等参数的变化规律。(2)运用动量理论建立了悬停和前飞状态下纵列式六旋翼大载荷无人机两副主旋翼的气动力模型,且在模型的建立过程中考虑了前、后旋翼尾迹之间相互干扰的影响。采用CFD方法对两副主旋翼悬停、前飞状态下的流场特性和气动特性进行计算分析,并将其与单旋翼数值模拟结果进行对比。在此基础上,分析两旋翼的纵向间距、轴向间距等参数对前、后旋翼气动特性的影响。(3)在分析纵列式六旋翼大载荷无人机两副主旋翼前飞状态下流场特性和气动特性的基础上,采用改进的粒子群算法,以两副主旋翼前飞状态下的总升力、总阻力为目标函数,以纵向间距、轴向间距和前倾角为约束条件,建立优化设计模型,对两副主旋翼的主要气动参数进行优化。(4)提出了纵列式六旋翼大载荷无人机设计方案,并对其动力系统、旋翼系统、传动系统以及整机气动布局进行详细设计。此外,计算分析了旋翼系统悬停和前飞状态下的升阻特性,并采用ANSYS Workbench分析了旋翼系统和减速器齿轮组的振动特性。论文创新性成果如下：(1)采用CFD方法对纵列式六旋翼大载荷无人机调节旋翼的气动特性进行数值模拟,得出了悬停、前飞状态下该旋翼的流场和气动力数据。此外,搭建了旋翼气动性能测试试验台,通过试验验证了本文数值模拟方法的有效性。(2)首次采用CFD方法对纵列式六旋翼大载荷无人机两副主旋翼悬停、前飞状态下的流场特性和气动特性进行了计算分析,并将其与单旋翼数值模拟结果进行对比,摸清了影响前、后旋翼气动特性的主要因素—纵向间距、轴向间距、前倾角、来流速度等参数与气动特性的关系。经对比结果表明,纵向间距、轴向间距和前倾角这三个参数对两副主旋翼的气动特性具有一定影响,且三者存在耦合作用。(3)针对纵列式六旋翼大载荷无人机设计过程中,纵向间距、轴向间距取值较难确定的难题,提出了一种通过全局优化确定主要气动参数最优取值的方法。结果表明,这种方法可以有效地确定最优取值,使纵列式六旋翼大载荷无人机两副主旋翼的气动性能得到了显著改善。(4)提出了纵列式六旋翼大载荷无人机的设计方案,确定了该无人机的气动布局,计算分析了旋翼系统悬停和前飞状态下的升阻特性,证明其可以实现大载荷的可行性,为我国自主研发大载荷无人机航空物探飞行平台提供了理论基础。
[Abstract]:At present, the technology of large load UAV still belongs to the frontier science and technology in the world, only in the United States, Britain, Canada, Germany, France and other countries. But our country is late and is still in the stage of research and development, which is far from the international advanced level. Therefore, the development of the large load UAV in the field of Aeronautical geophysical exploration is stable and practical. It is an urgent problem to be solved in China. The column type UAV has the advantages of large body volume, large center of gravity change range and strong anti side wind ability. It has broad application prospects in military and civil two fields. However, there is a certain overlap area between the rear rotor and the two rotor because of the column type. There is mutual aerodynamic interference between each other, which can not be modeled as a single rotor, but need to be coupled together to consider it. This adds to the difficulty of the calculation of the rotor flow field and aerodynamic characteristics. For this reason, this paper combines the national "863" project "heavy load intelligent physical exploration special unmanned helicopter development" (2013AA063903). The research work on the flow field characteristics and aerodynamic characteristics of the large load unmanned aerial vehicle (UAV) rotor system of the column type six rotor is carried out. The main contents of the thesis include: (1) the CFD method is used to simulate the suspension state of the large load unmanned aerial vehicle (UAV) regulating rotor of the column type six rotor, and the flow field characteristics are analyzed. The basic aerodynamic characteristics of the rotor are measured and the effectiveness of the numerical simulation method is verified. On this basis, the aerodynamic characteristics of the adjusting rotor in the forward flight state are analyzed, and the changes of the lift force, the drag and torque with the front tilt angle, the flow velocity, the rotor speed and other parameters are obtained respectively. (2) using the momentum theory to set up the suspension. The aerodynamic model of the two vice main rotor of a large load unmanned aerial vehicle (six rotor) under the state of stop and forward flight, and the influence of mutual interference between the rear rotor wake and the front rotor wake in the establishment of the model, the flow field characteristics and aerodynamic characteristics in the front flight state are calculated and analyzed with the CFD method. The numerical simulation results are compared. On this basis, the longitudinal spacing of the two rotor, the axial spacing and other parameters on the aerodynamic characteristics of the front and rear rotor are analyzed. (3) on the basis of the analysis of the flow field characteristics and aerodynamic characteristics in the front flight state of the two vice main rotor of the column type six rotor large load UAV, the improved particle swarm algorithm is adopted, with two pairs of pairs. The total lift and total drag of the main rotor are the objective function, the optimum design model is set up with the longitudinal spacing, the axial distance and the front angle as the constraint conditions. The main aerodynamic parameters of the two main rotor are optimized. (4) the design scheme of the column type six rotor large load unmanned aircraft is put forward, and the power system, the rotor system and the transmission are also proposed. The system and the pneumatic layout of the whole machine are designed in detail. In addition, the rise resistance characteristics of the rotor system in hovering and forward flight are calculated and analyzed, and the vibration characteristics of the rotor system and the reducer gear group are analyzed with ANSYS Workbench. The innovative results of the paper are as follows: (1) the adjustment of the column type six rotor large load UAV by the CFD method The aerodynamic characteristics of the rotor are numerically simulated, and the flow field and aerodynamic data of the rotor in the forward flight state are obtained. In addition, the rotor aerodynamic performance test rig is built, and the validity of the numerical simulation method is verified by the test. (2) the CFD method is used for the first time of the column type six rotor large load unmanned aerial vehicle (UAV) two main rotor suspension. The flow field characteristics and aerodynamic characteristics in the state of stop and forward flight are calculated and analyzed, and compared with the numerical simulation results of the single rotor, the relationship between the main factors of the aerodynamic characteristics of the rear rotor, such as the longitudinal spacing, the axial distance, the front angle, the velocity of the flow and the aerodynamic characteristics, is found out. The longitudinal spacing is shown by the comparison results. The three parameters of the axial distance and the front angle have a certain influence on the aerodynamic characteristics of the two pair of the main rotor, and the three are coupled. (3) in the design process of the large load unmanned aerial vehicle of the column type six rotor, the longitudinal spacing and the axial spacing are difficult to determine. A global optimization is proposed to determine the optimal parameters of the main aerodynamic parameters. The results show that the method can effectively determine the optimal value and make the aerodynamic performance of the two main rotor of the column six rotor large load UAV significantly improved. (4) the design scheme of the column type six rotor large load UAV is proposed, the aerodynamic layout of the unmanned aerial vehicle is determined, and the rotor system hovering is calculated and analyzed. The rise and drag characteristics of the forward flight show that it can realize the feasibility of large load, and provides a theoretical basis for the independent research and development of China's large load UAV Aero Geophysical flight platform.
【学位授予单位】：吉林大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：V279
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本文编号：1924260