基于非定常动量源方法的倾转旋翼机气动分析及性能优化

发布时间：2018-04-29 17:14

本文选题：倾转旋翼机 + 非定常干扰特性　；参考：《南京航空航天大学》2016年硕士论文

【摘要】：倾转旋翼机具有比常规直升机高得多的前飞速度和续航能力,又具有常规固定翼飞机所不具备的垂直起降和悬停能力,能满足多种飞行任务的需要,因此近年来无论在军用或民用方面对倾转旋翼机的需求越来越大。然而,作为介于直升机和固定翼之间的一种机型,倾转旋翼机具有比两者更为复杂的气动干扰现象,严重影响了倾转旋翼机的气动性能。因此,开展倾转旋翼机复杂气动干扰的分析及气动优化设计的研究具有重要的理论和实际意义。本文基于非结构混合网格系统,提出并建立了用于倾转旋翼机气动干扰特性分析的非定常动量源方法,并应用建立的数值模拟方法分别开展倾转旋翼机多状态气动干扰流场分析、倾转旋翼机结构/气动参数的影响特性分析、倾转旋翼机多状态气动优化设计。主要研究工作包括以下几个方面:第一章,针对倾转旋翼机复杂的气动干扰问题,分析了国内外在倾转旋翼机流场数值模拟方法、动量源方法以及倾转旋翼机气动外形优化设计研究方面的技术现状及难点,并指出了采用耦合新型非定常动量源模型的数值模拟方法对倾转旋翼机非定常流场及气动特性数值模拟的必要性和重要意义。第二章,为了充分捕捉附面层内粘性流动对倾转旋翼机气动特性的影响,同时考虑多种飞行状态特点,构建了底层三棱柱网格—外层四面体网格相结合的非结构混合网格系统。为了满足非定常动量源计算的需要,将非结构混合网格、二维翼型网格和笛卡尔搜索网格相耦合,建立了一套倾转旋翼机干扰流场数值模拟的网格生成方法,并给出了多种网格生成结果。第三章,在建立的网格生成方法的基础上,构建了适用于不同飞行状态下倾转旋翼机非定常流场数值模拟方法。为了兼顾倾转旋翼机干扰流场的模拟精度和效率,首先,提出了一种介于贴体CFD方法与传统动量源方法之间的非定常动量源方法;然后,将Navier-Stokes方程作为控制方程,湍流模型选取了一方程S-A模型,采用了双时间推进方法;并引入OpenMP并行加速技术。在此基础上,通过不同模型旋翼流场的算例计算,验证了本文方法的有效性,同时对比反映了非定常动量源方法具有较好的计算精度和效率。第四章,为了揭示倾转旋翼机的非定常气动干扰现象,在上述分析方法基础上,对悬停、前飞(直升机模式、飞机模式)以及过渡状态下倾转旋翼机的全机气动干扰流场进行了模拟。细致分析了悬停状态下倾转旋翼机特有的“喷泉效应”、不同前飞模式下干扰程度和方式的差别以及不同过渡状态下的倾转旋翼机气动特性变化特征等,获得了多状态下倾转旋翼机非定常干扰流场的特性。第五章,为了获得不同结构/气动参数对倾转旋翼机干扰流场的影响特性,针对不同飞行状态,分别开展了旋翼/机翼间距、机翼襟翼角、旋翼转向及尾翼构型对全机流场的干扰影响,获得了相应的参数影响规律。并进一步分析了各部件对机翼的气动干扰方式和程度,为进行倾转旋翼机多目标、多状态的气动优化打下了基础。第六章,将CFD方法和代理模型方法相结合,建立了一套适用于倾转旋翼机气动外形综合优化的高效优化设计方法。为了提高倾转旋翼机的运输性能,以降低干扰状态下悬停状态的机身增重和前飞状态下的阻力为优化目标,选取机翼后掠角、翼型配置等作为设计参数,对悬停、前飞状态下的倾转旋翼机进行了综合优化设计,获得了倾转旋翼机先进气动外形的设计结果。
[Abstract]:The tiltilla has a much higher speed and endurance than the conventional helicopter. It also has the vertical landing and hovering capacity that the conventional fixed wing aircraft does not have, and can meet the needs of various flight tasks. Therefore, in recent years, the demand for the tilting rotor is increasing both in military and civil aspects. A type of aircraft between the aircraft and the fixed wing, the tilting rotor has more complex aerodynamic interference than both, seriously affecting the aerodynamic performance of the tilting rotor. Therefore, it is of great theoretical and practical significance to carry out the analysis of the complex aerodynamic interference and the aerodynamic optimization design of the tilterer. The non steady momentum source method for the aerodynamic interference characteristic analysis of the tilting rotor machine is proposed and established. The numerical simulation method is used to analyze the multi state aerodynamic interference flow field of the tilting rotor machine, the influence characteristic analysis of the structure / aerodynamic parameters of the tilting rotor machine, and the multi state aerodynamic optimization design of the tilting rotor machine. The main research work includes the following aspects: in the first chapter, in view of the complicated aerodynamic interference of the tilting rotor machine, the numerical simulation method of the flow field of the tilting rotor machine, the momentum source method and the aerodynamic configuration optimization design of the tilting rotor machine are analyzed. The numerical simulation of the momentum source model is necessary and important for the unsteady flow field and aerodynamic characteristics of the tilting rotor machine. In the second chapter, in order to fully capture the influence of the viscous flow in the surface layer on the aerodynamic characteristics of the tilterer, and considering the special points of a variety of flight States, the bottom three prism grid and the outer layer are constructed. In order to meet the needs of the unsteady momentum source calculation, the unstructured hybrid grid, the two-dimensional airfoil grid and the Descartes search grid are coupled to meet the needs of the unsteady momentum source calculation. A set of grid generation methods for the numerical simulation of the disturbance flow field of the tilting rotor machine is established, and the results of various grid generation are given. Third chapters, On the basis of the established grid generation method, a numerical simulation method for the unsteady flow field of the tilting rotor machine for different flight states is constructed. In order to give consideration to the simulation accuracy and efficiency of the interfering flow field of the tilting rotor, a non constant momentum source method between the body fitted CFD method and the traditional dynamic source method is proposed. The Navier-Stokes equation is used as the control equation, the turbulence model selects a equation S-A model, adopts the double time propulsion method, and introduces the OpenMP parallel acceleration technique. On this basis, the effectiveness of the method is verified by calculating the flow field of different models of the rotor, and the comparison reflects that the non steady momentum source method has a comparison. Good calculation accuracy and efficiency. In the fourth chapter, in order to reveal the unsteady aerodynamic interference of the tilting rotor machine, on the basis of the above analysis method, the whole aerodynamic disturbance flow field of the hovering, forward flight (helicopter mode, aircraft mode) and the transition state lower tilting rotor is simulated. The hovering rotor machine is carefully analyzed. The special "fountain effect", the difference of the interference degree and mode in the forward flight mode and the characteristics of the aerodynamic characteristics of the tilting rotor machine under different transition states, the characteristics of the unsteady disturbance flow field of the multi state tilting rotor machine are obtained. In the fifth chapter, the interference flow field of the tilting rotor machine with different structure / aerodynamic parameters is obtained. The influence of the rotor / wing spacing, the wing flap angle, the wing steering and the tail wing configuration on the whole flow field is carried out in different flight conditions, and the corresponding parameter influence rules are obtained. Furthermore, the aerodynamic interference mode and degree of each component to the wing are further analyzed, in order to carry out the multi state of the tilting rotor machine and multi state. The sixth chapter, combining the CFD method with the agent model method, establishes a set of efficient optimization design method for the comprehensive optimization of the aerodynamic shape of the tilting rotor machine. In order to improve the transport performance of the tilting rotor machine, the weight gain and the resistance in the forward flight state of the hovering state are reduced. To optimize the target, select the wing sweep angle and the airfoil configuration as the design parameters, the optimization design of the tilting rotor in the hovering and forward flight is carried out, and the design results of the advanced aerodynamic shape of the tilting rotor are obtained.

【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：V211.52

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