翼盘式太阳能飞行器的研究与设计

发布时间：2018-12-29 16:04

【摘要】：太阳能飞行器是一类将太阳能作为主要动力源,可实现大高度、长航距、长航时的新型飞行器,在理想情况下,太阳能飞行器可以在临近空间实现跨昼夜,远期可望实现连续跨年环球飞行,如此诱人的前景,加之光伏发电技术和飞行器技术的不断发展,催生了对太阳能飞行器持续研究的热潮。典型太阳能飞行器仍然采用传统飞行器的十字形布局,只不过是将传统飞行器的动力源替换为光伏薄膜电池。然而,由于光伏技术发展滞后,光伏电池效率低下,单纯将传统飞行器的动力源置换为太阳能并不能解决问题。为此,人们设计了一系列大展弦比、轻质、大表面积飞行器,一是借助机翼的大展弦比结构,弥补动力不足的问题;二是使用大表面积的薄膜电池来提供充足的升力。然而,与此同时带来了另外一个难题:大展弦比结构带来的刚度弱化问题。基于以上背景,提出一种新型翼盘式太阳能飞行器——即同时考虑飞行器的气动效率和光伏薄膜电池的铺设面积,将盘型升力体和固定机翼结合起来,飞行方式参考直升飞机。该新型飞行器能够实现悬空、垂直短距起降等功能,同时,由于基本克服了能量来源的制约,从而可实现大高度、长航距、超长巡航时间等飞行功能。首先,针对提出的新型飞行器布局,对飞行器的基本结构进行设计,包括动力系统分散和驱动末端化设计、盘型机体组件、旋转机翼、副翼系统等部件;然后,结合设计的飞行器结构,针对不同的飞行姿态,对飞行器的飞行模式进行规划——即通过周期性的调节飞行器机翼末端的动力螺旋桨和副翼系统来实现飞行器的各种飞行姿态,具体包括飞行器的悬停、巡航以及爬升/下滑等典型飞行状态。其次,根据前面规划的飞行姿态,结合飞行器的各项设计指标,利用动量—叶素理论对飞行器的机翼气动力进行理论分析,以得到飞行器机翼升阻力和下洗速度等。然后,基于AWB分析软件,对飞行器的机体和机翼进行气动分析,接着利用单向流固耦合理论,将模拟得到的气动载荷分别加载至机体组件和机翼组件,分析各主要部件的受载情况,并将分析结果作为进一步结构优化的参考。最后,针对光伏发电系统中光伏电池的动态特性进行研究,建立了光伏电池的数学模型,并对影响光伏电池输出效率的两大因素——光照强度和环境温度进行仿真模拟;根据仿真结果可知,光伏电池并非线性输出,因而需要将电池的输出稳定到一个额定电压,为此,利用扰动观测法、增量电导法等追踪策略实现光伏电池峰值的输出。接着,根据我国不同地域和时节的光照情况,对飞行器能源系统的工作模式进行规划,保证飞行器可以实现持续跨昼夜飞行,此外,根据飞行器的不同飞行模式,制定了飞行器的能源供应策略。
[Abstract]:Solar vehicle is a kind of new type of aircraft which takes solar energy as the main power source and can achieve high altitude, long distance and long voyage. Ideally, solar vehicles can span day and night in the near space. It is expected to realize continuous transannual flights around the world in the long run. This attractive prospect, coupled with the continuous development of photovoltaic power generation technology and aircraft technology, has given birth to a wave of continuous research on solar vehicles. The typical solar vehicle still adopts the cross-shaped layout of the traditional aircraft, which is only to replace the power source of the traditional vehicle with the photovoltaic thin-film cell. However, because of the lag of photovoltaic technology and the low efficiency of photovoltaic cells, simply replacing the power source of traditional aircraft with solar energy can not solve the problem. For this reason, a series of aircraft with large aspect ratio, light weight and large surface area have been designed, one is to make up for the problem of insufficient power with the aid of the large aspect ratio structure of the wing, and the other is to use thin film batteries with large surface area to provide sufficient lift. However, at the same time, it brings another problem: stiffness weakening caused by large aspect ratio structure. Based on the above background, a new type of wing disk solar vehicle is proposed, that is, the aerodynamic efficiency of the aircraft and the lay area of the photovoltaic thin film cell are considered at the same time, the disk lift body is combined with the fixed wing, and the flight mode is referred to the helicopter. The new aircraft can achieve the functions of suspension, vertical short-range take-off and landing, etc. At the same time, because of overcoming the restriction of energy source basically, it can realize the flight functions such as large altitude, long distance and long cruise time. First of all, the basic structure of the aircraft is designed for the proposed new aircraft layout, including the power system dispersion and drive terminal design, disk airframe components, rotating wing, aileron system and other components; Then, combined with the design of the structure of the aircraft, for different flight attitude, To plan the flight mode of the aircraft, that is, to realize the flight attitude of the aircraft by periodically adjusting the power propeller and the aileron system at the end of the wing of the aircraft, including the hovering of the aircraft. Typical flight conditions such as cruising and climbing / sliding. Secondly, according to the planned flight attitude, combined with the various design indexes of the aircraft, the aerodynamic force of the aircraft wing is theoretically analyzed by using the momentum-leaf element theory, so as to obtain the lift resistance and the downwash velocity of the aircraft wing. Then, based on the AWB analysis software, the aerodynamic analysis of the airframe and wing of the aircraft is carried out, and then the simulated aerodynamic loads are loaded into the airframe and wing components respectively by using the unidirectional fluid-solid coupling theory. The load of the main components is analyzed, and the results are used as the reference for further structural optimization. Finally, the dynamic characteristics of photovoltaic cells in photovoltaic power system are studied, the mathematical model of photovoltaic cells is established, and the two factors that affect the output efficiency of photovoltaic cells, namely, light intensity and ambient temperature, are simulated. According to the simulation results, the photovoltaic cell is not nonlinear output, so it is necessary to stabilize the cell output to a rated voltage. For this reason, the peak output of photovoltaic cell is achieved by using perturbation observation method, incremental conductance method and other tracking strategies. Then, according to the illumination situation of different regions and seasons in our country, the working mode of the energy system of the aircraft is planned to ensure that the aircraft can fly continuously day and night, in addition, according to the different flight mode of the aircraft, An energy supply strategy for the aircraft has been developed.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：V272

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