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Development and Application of Reduced Order Models for Buffeting and Buzz

抖振和嗡嗡声降阶模型的开发和应用

基本信息

批准号：
387771741
负责人：
Professor Dr.-Ing. Christian Breitsamter
金额：
--
依托单位：
Lehrstuhl für Aerodynamik und Strömungsmechanik
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2017
资助国家：
德国
起止时间：
2016-12-31 至 2020-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/387771741?language=en
关键词：
Development Application Reduced Order Models

项目摘要

The determination of the limits of the flight envelope is a major task in aircraft design and analysis. In this regard, aeroelastic phenomena occur that are characterized by the coupling of aerodynamic, structural-elastic and inertial forces. In addition to the self-induced excitation (flutter), dynamic response problems such as buffeting and buzz are of particular importance. For efficiency reasons, the unsteady flow simulations are mainly carried out using potential theory methods. These approaches, however, cannot predict the aerodynamic characteristics of the transonic flight regime adequately since aerodynamic nonlinearities induced by shocks an flow separation are not reproduced. In contrast, the unsteady aerodynamic forces can be determined with sufficient accuracy using state-of-the-art CFD (computational fluid dynamics) methods. This advantage, however, comes along with a drastic increase of the computational costs, which cannot be met with today's capacities for the huge amount of calculations needed for the aeroelastic analysis process. One way to limit the computional effort is to use Reduced Order Models (ROMs) that are conditioned and calibrated using selected CFD simulation data. A ROM is denoted as a simplified model that efficiently reflects the dominant characteristics of the underlying system. The goal of this project is the development of a novel nonlinear ROM method, which can be used to address transonic buffeting and buzz. For this purpose, the validated ROM methodology designed for flutter predictions has to be expanded in order to capture the unsteady aerodynamic mechanisms related to buffet and buzz. As a consequence, the integral forces and moments or generalized aerodynamics forces can be computed by the ROM, which leads to a significant acceleration of unsteady aerodynamic and aeroelastic analyses.

飞行包线极限的确定是飞机设计和分析中的一项主要任务。在这方面，气动弹性现象发生，其特征在于空气动力、结构弹性和惯性力的耦合。除了自激激励（颤振），动态响应问题，如抖振和嗡嗡声是特别重要的。由于效率的原因，非定常流模拟主要采用势理论方法进行。然而，这些方法不能充分地预测跨音速飞行状态的气动力特性，因为激波和气流分离引起的气动力非线性不能再现。相比之下，非定常气动力可以使用最先进的CFD（计算流体动力学）方法以足够的精度确定。然而，这一优点沿着而来的是计算成本的急剧增加，这是目前气动弹性分析过程所需的大量计算能力所不能满足的。限制计算工作量的一种方法是使用降阶模型（ROM），这些模型使用选定的CFD模拟数据进行调节和校准。ROM被表示为有效地反映底层系统的主要特征的简化模型。本计画的目标是发展一种新的非线性ROM方法，可用来解决跨音速抖振和嗡鸣。为此，必须扩展为颤振预测而设计的有效ROM方法，以捕捉与抖振和嗡鸣有关的非定常气动力机制。因此，积分力和力矩或广义气动力可以由ROM计算，这导致非定常气动力和气动弹性分析的显着加速。