带可倾转升力风扇飞翼布局的气动特性研究及优化

发布时间：2018-01-07 08:42

本文关键词：带可倾转升力风扇飞翼布局的气动特性研究及优化　出处：《南昌航空大学》2016年硕士论文　论文类型：学位论文

【摘要】：鉴于带升力风扇飞翼布局飞机兼具垂直/短距起降和飞翼布局飞机的优点之外,还具有推重比较大、净升效率较高、无热喷流等优点。带升力风扇以实现飞机的短距/垂直起降将会是在以后很长时间内的一个重要研究课题。但由于带可倾转升力风扇飞翼布局飞机的升力风扇设置在机翼中央,在平飞时机翼上的风扇开口将对飞机的气动特性产生重要影响,因此,研究其气动特性与开口形状的关系显得尤为重要。本文采用CFD数值方法对在平飞状态下带可倾转升力风扇飞翼布局无人机为安装升力风扇而开口的机翼气动特性进行了研究,分析开口机翼在平飞状态不同来流速度下以及不同迎角下开口机翼的气动特性。主要研究内容为:1建立开口机翼开口处最大纵向剖面二维模型,通过ICEM进行几何模型的结构网格化分,并将结构网格导入到FLUENT进行数值仿真。结果表明,在相同条件下,开口机翼的气动特性明显变差,但俯仰的操控性较好。且开口机翼的开口处产生了涡,损失了部分的能量,从而进一步降低了的开口机翼的气动特性。2通过对九组优化二维模型气动特性进行了对比,对机翼开口机翼截面进行了不同的修形,结果表明:开口机翼开口处完全圆弧优化且开口前段截面前倾适当角度得到的气动特性最佳。优化后开口机翼的气动特性得到了显著的提升。3建立开口机翼三维几何模型,通过ICEM进行几何模型的结构网格化分,并将结构网格导入到FLUENT进行数值仿真。结果表明,三维仿真结果和二维仿真结果类似。开口机翼同样是由于损失了部分机翼,且在开口处产生了涡,损耗了部分能量是导致开口机翼气动特性变差的重要原因。4根据二维模型的优化方向,选定了十六个优化方向,并进行三维数值仿真。结果表明,开口机翼开口处前段进行内切圆弧化处理得到的气动特性最佳。从流线图看,其产生的涡极小,相对于未优化开口机翼来说可以忽略不计,而优化后开口机翼开口处后段产生的涡从涡的范围以及强度来说也变小了很多,这些都是改善开口机翼气动特性的重要方法。综上所述,带升力风扇飞翼布局飞机由于机翼中间开口,造成气动特性降低,但通过对开口的合理设计,可有效改善其气动特性;二维优化一定程度上可以代表优化的方向,但经三维优化的结果更加明显。
[Abstract]:In view of the fact that with the lift fan flying wing aircraft has both advantages of V / STOL and flying wing aircraft, has given rise is relatively large, the net efficiency is high, the advantages of no hot jet. With the lift fan aircraft to achieve short takeoff / vertical landing will be an important research topic in the future for a long time. The lift fan with tilting lift fan flying wing set in the central wing, flying wing in the fan opening on the aircraft aerodynamic characteristics have an important impact, therefore, to study the relationship between the dynamic characteristics of gas and the shape of the opening is particularly important. This paper uses the CFD numerical method of wings to fly in the state flat with tilting lift fan flying wing UAV and the opening for the installation of lift fan aerodynamic characteristics of the wing in the flat state analysis of opening different flow velocity and different The opening angle of the aerodynamic characteristics of the wing. The main contents are as follows: 1 the establishment of the opening at the opening of the maximum longitudinal profile of the wing structure of two-dimensional model, grid geometry model by ICEM, and the structure of the grid into FLUENT numerical simulation. The results show that under the same conditions, opening the aerodynamic characteristics of the wing worse, but control of the pitch better. The opening and the opening of the wing vortex, the loss of some energy, thus further reducing the opening wing aerodynamic characteristics of the.2 based on nine dimensional model optimization of aerodynamic characteristics were compared by different modification of wing wing opening the results show that the opening section of wing opening and opening the front section completely optimum arc forward proper angle of aerodynamic characteristics was optimized. The best opening of the aerodynamic characteristics of the wing can significantly improve the establishment of open.3 The three-dimensional geometric model of grid structure, the geometric model by ICEM, and the structure of the grid into FLUENT numerical simulation. The results show that the 3D simulation results similar to two-dimensional simulation results. The wing is also due to the loss of the opening part of the wing, and produced a vortex in the opening, a part of the energy loss is the result of.4 an important reason for opening the wing's aerodynamic characteristics of variation according to the direction of optimization of two dimensional model, selected sixteen optimization direction, and three-dimensional numerical simulation. The results show that the opening of the opening of the front wing inscribed circle arc processing of aerodynamic characteristics was the best. From the flow chart, the minimum vortex, compared with optimization of wing is negligible opening, and the optimized wing opening period after opening the vortex generated by the vortex from the range and strength is also a lot smaller, these are the improvement of opening An important method of aerodynamic characteristics of wings. To sum up, with the flying wing aircraft wing lift fan as an opening in the middle, resulting in reduced aerodynamic characteristics, but by the reasonable design of the opening, can effectively improve its aerodynamic characteristics; two-dimensional optimization to a certain extent can represent the direction of optimization, but the three-dimensional optimization results more obvious.

【学位授予单位】：南昌航空大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：V211.4

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