Coupled CSD/CFD non-linear aeroelastic trim of free-flying flexible aircraft

Romanelli, Giulio; Castellani, Michele; Mantegazza, Paolo; Ricci, Sergio

doi:10.2514/6.2012-1562

Cited by 16 publications

(16 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As such, calculations are usually performed on wings already optimized for the transonic flow regime; a linear potential method seems sufficient to predict the wing loading and deformation and should yield results similar to those obtained using nonlinear methods, except for the drag. Note, however, that this result strongly depends on the geometry, as results previously reported in the literature [21] suggest that linear methods are not necessarily accurate in transonic cases. In any case, if a linear model is used to compute the wing deflection, a single nonlinear rigid aerodynamic calculation should be performed on the deformed shape in order to estimate more accurate aerodynamic loads.…”

Section: Discussionmentioning

confidence: 55%

“…Note that the ability of linear methods to predict wing displacements accurately seems to be quite sensitive to the geometry. Results previously reported by Romanelli et al [21] show that the doublet lattice method was less accurate than Euler computations, especially near the wingtip. However, it is unclear whether the authors corrected the method with higher-fidelity data.…”

Section: Discussionmentioning

confidence: 79%

“…The most extensive one is probably the first Aeroelastic Prediction Workshop organized by the American Institute of Aeronautics and Astronautics in 2012 [19,20]. In this workshop, some authors, such as Romanelli et al [21] and Acar and Nikbay [22], compared their results obtained with linear potential or Euler equations to experimental data. Particularly, Romanelli et al observed noticeable discrepancies between wing deflections obtained using the doublet lattice method and the Euler formulation.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Effect of Levels of Fidelity on Steady Aerodynamic and Static Aeroelastic Computations

et al. 2020

View full text Add to dashboard Cite

Static aeroelastic deformations are nowadays considered as early as in the preliminary aircraft design stage, where low-fidelity linear aerodynamic modeling is favored because of its low computational cost. However, transonic flows are essentially nonlinear. The present work aims at assessing the impact of the aerodynamic level of fidelity used in preliminary aircraft design. Several fluid models ranging from the linear potential to the Navier–Stokes formulations were used to solve transonic flows for steady rigid aerodynamic and static aeroelastic computations on two benchmark wings: the Onera M6 and a generic airliner wing. The lift and moment loading distributions, as well as the bending and twisting deformations predicted by the different models, were examined, along with the computational costs of the various solutions. The results illustrate that a nonlinear method is required to reliably perform steady aerodynamic computations on rigid wings. For such computations, the best tradeoff between accuracy and computational cost is achieved by the full potential formulation. On the other hand, static aeroelastic computations are usually performed on optimized wings for which transonic effects are weak. In such cases, linear potential methods were found to yield sufficiently reliable results. If the linear method of choice is the doublet lattice approach, it must be corrected using a nonlinear solution.

show abstract

Section: Discussionmentioning

confidence: 55%

Section: Discussionmentioning

confidence: 79%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effect of Levels of Fidelity on Steady Aerodynamic and Static Aeroelastic Computations

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Among its features, there is an aeroelastic interfacing scheme, based on a moving least-square interpolation strategy, providing all the needed functionalities to set the appropriate aerodynamic boundary conditions imposed by a deforming structure while driving a connected hierarchical mesh deformation within an arbitrary Lagrangian-Eulerian formulation. An extended discussion of its aeroelastic capabilities can be found in [25].…”

Section: A Aerodynamic Solvermentioning

confidence: 99%

Reduced-Order Models for Computational-Fluid-Dynamics-Based Nonlinear Aeroelastic Problems

Mannarino

Dowell

2015

AIAA Journal

View full text Add to dashboard Cite

In this work, a nonlinear state-space-based identification method is proposed to describe compactly unsteady aerodynamic responses. Such a reduced-order model is trained on a series of signals that implicitly represent the relationship between the structural motion and the aerodynamic loads. The determination of the model parameters is obtained through a two-level training procedure where, in the first stage, the matrices associated to the linear part of the model are computed by a robust subspace projection technique, whereas the remaining nonlinear terms are determined by an output error-minimization procedure in the second stage. The present approach is tested on two different problems, proving the convergence toward the reference results obtained by a computational fluid dynamics solver in linear and nonlinear, aerodynamic, and aeroelastic applications, whereas the aerodynamic reduced-order models are coupled with the related structural mechanical systems, demonstrating the ability of capturing the main nonlinear features of the response. The robustness of the reduced-order model is then tested considering a series of inputs with varying amplitudes and frequencies outside the range of interest and computing aeroelastic responses with nonnull pretwist angles. NomenclatureA a , B a , C a , D a = linear subparts of the reduced-order model b = half-chord, c∕2 E a , F a = nonlinear subparts of the reduced-order model f a = aerodynamic loads h, θ = plunge and pitch degrees of freedom k = ωc∕U ∞ ; reduced frequency N a = number of aerodynamic states, size of x a N out = number of aerodynamic output, size of f a q ∞ = 1 2 ρ ∞ U 2 ∞ ; dynamic pressure t = continuous time V = U ∞ ∕ω θ b μ p ; reduced velocity V bif = bifurcation speed x a = aerodynamic state x s = structural dynamics state β LE , β TE = leading-and trailing-edge control surface deflections μ = m∕πρ ∞ b; mass-to-fluid ratio τ = ω θ t; nondimensional time ϕx a = nonlinear functions of the aerodynamic reduced-order model ω i = natural frequency of the ith degree of freedom

show abstract

“…Thus, the idea is to exploit GPUs architecture to accelerate an explicit FSI solver, keeping a low memory usage. Furthermore, the structural FEM model is reduced to a modal representation [12,1] in order obtain both an accurate and efficient FSI formulation.…”

Section: Introductionmentioning

confidence: 99%

A GPU-Accelerated Compressible RANS Solver for Fluid-Structure Interaction Simulations in Turbomachinery

Mangani¹,

Casartelli²,

Romanelli³

et al. 2016

Volume 7B: Structures and Dynamics

View full text Add to dashboard Cite

Computational Fluid Dynamics (CFD) is a fundamental tool for the aerodynamic development in industrial applications. In the usual approach structural deformation due to aerodynamic and thermal loads is often neglected. However, in some cases, where power efficiency is the ultimate goal, an accurate prediction of the structure-flow interaction is essential. This is particularly true for trim and flutter analysis of aircrafts, helicopter and turbomachinery blades. Particularly, turbomachinery trim and flutter predictions still represent a challenge due to phenomena like rotor-stator interaction, separations and shock waves. The usual time-linearised, frequency-domain strategies can be inadequate when this kind of strong non-linear phenomena occur in the flow, making necessary full non-linear time-domain simulations or the harmonic balance technique. Beside flutter, another important aspect, not yet adequately investigated, is the trim analysis, which is fundamental for an accurate steady simulation that aims to consider static blade elasticity for the performance evaluation of turbomachines. Moreover, alongside the obvious contribution given by centrifugal loads to the blade deformation, a not less important source of blade displacement is the thermal effect due to the heat exchanged between the solid and the fluid domains. In particular, for some geometries and operating conditions, thermal effects can be more important than centrifugal effects for the blade deformations. Considering multiple sources of blade deformation (elastic, centrifugal and thermal) in a what is often called “multiphysics” approach is nowadays more and more important, if the goal of the analysis is geometry optimization. To achieve this, next to result’s accuracy also computational efficiency is required, when hundreds of aeroelastic simulations have to be performed in a typical optimization loop. Modern GPUs can be exploited to pursue this goal thanks to their high peak computational power available at relatively low costs and low power consumption with respect to the usual CPUs. In this paper a pioneer work describing the impact of static deformation due to blade elasticity, thermal and centrifugal effects on the performances and power efficiency will be provided. Alongside with accurate results, computational efficiency is taken into account. The purpose of this article is to show the architecture of a GPU-accelerated Fluid-Structure Interaction (FSI) solver for compressible viscous flows. The proposed approach is validated with a typical industrial case, i.e. a turbocharger transonic centrifugal-compressor provided by ABB. The effects of trimmed solutions on the most important integral quantities (i.e. mass flow, characteristic curves, mass-averaged outflow profiles) are investigated and a comparison with pure aerodynamic results is provided. Due to the high blade stiffness and thus the very small displacements obtained with the trim solutions, for the particular case presented in the paper the aeroelastic solutions basically provide nearly the same results as the pure aerodynamic solutions.

show abstract

Coupled CSD/CFD non-linear aeroelastic trim of free-flying flexible aircraft

Cited by 16 publications

References 21 publications

Effect of Levels of Fidelity on Steady Aerodynamic and Static Aeroelastic Computations

Effect of Levels of Fidelity on Steady Aerodynamic and Static Aeroelastic Computations

Reduced-Order Models for Computational-Fluid-Dynamics-Based Nonlinear Aeroelastic Problems

A GPU-Accelerated Compressible RANS Solver for Fluid-Structure Interaction Simulations in Turbomachinery

Contact Info

Product

Resources

About