Efficient aeroelastic reduced order model with global structural modifications

Abstract

Time domain aeroelastic analysis has high computing costs when using computational fluid dynamics. These costs become prohibitive when the structural model undergoes large changes from the baseline design, as within an aircraft design process. To overcome this realistic challenge, we have developed, implemented, and demonstrated an efficient method that is robust in the presence of global modifications of the structure. The method consists of: a) a reduced order model of the linearized Navier-Stokes equations generated around an aeroelastic equilibrium that depends, in turn, on the structural model; b) an approximate structural dynamic reanalysis method valid for global modifications of the structure; and c) a mechanism to exchange information between fluid and structural solvers without need for calculating at each iteration of the structural design an eigenvalue problem of the modified structure. The resulting aeroelastic reduced order model is demonstrated for the AGARD 445.6 wing, and material properties are varied up to 100% from their original values. It is found that: a) predictions of the time domain aeroelastic response and of the flutter speed are accurate for all modifications of the structure; and b) the computational efficiency of the proposed aeroelastic reduced order model is linearly proportional to the number of structural configurations considered. The method, therefore, is ideally suited for optimization and uncertainty studies.

Hybrid deep neural network based prediction method for unsteady flows with moving boundary

“…Reduced order modeling (ROM), such as proper orthogonal decomposition (POD) (Dowell, 1997) and dynamic mode decomposition (DMD) (Schmid, 2010), offers the potential to simulate physical and dynamic systems with substantially increased computational efficiency while maintaining reasonable accuracy. A Lot of researches (Chen et al, 2018;Jovanovie et al, 2014;Hemati et al, 2014) have been carried out to analyze flow fields with low-dimensional representations using these methods. But most of these investigations are linear or weakly nonlinear methods with some strong assumptions, which limits the applications of these methods to more complex unsteady flows.…”

Analysis on location of maximum vibration amplitude in panel flutter

“…Thus, in the analysis of panel flutter, the aero-elastic model consists of two components: aerodynamic modeling and structural modeling. 9…”

“…Thus, in the analysis of panel flutter, the aero-elastic model consists of two components: aerodynamic modeling and structural modeling. 9 For the modeling of the aerodynamics, usually, four aerodynamic methods are considered in panel flutter 10 : potential flow theory, Piston Theory (PT), computational fluid dynamic (CFD) based on Euler equations, and computational fluid dynamic based on N-S equations. In the early stage of study on panel flutter, the potential flow theory was widely used.…”

An aerodynamic ROM of the blade subjected to wake based on Fourier method for flow

“…Pagliuca and Timme used a POD ROM to obtain both the flight dynamic and aerodynamic responses of an aircraft subjected to external disturbances, and they found that the ROM can accurately reproduce the behavior of the coupled system during gust encounter. Chen et al developed a POD ROM for aeroelastic analysis of a modifiable structure . Their model combines the extended Kirsch method and a POD ROM to describe the modal characteristics of structure with large modifications.…”

“…Chen et al developed a POD ROM for aeroelastic analysis of a modifiable structure. 27 Their model combines the extended Kirsch method and a POD ROM to describe the modal characteristics of structure with large modifications.…”