Modeling the LCO of a Delta Wing with an External Store Using a High Fidelity Structural Model

2005 ◽  
Author(s):  
Peter Attar ◽  
Earl Dowell ◽  
Deman Tang
Keyword(s):  
Structural Model ◽  
Delta Wing ◽  
High Fidelity

Modeling Delta Wing Limit-Cycle Oscillations Using a High-Fidelity Structural Model

2005 ◽  
Vol 42 (5) ◽  
pp. 1209-1217 ◽  
Author(s):  
Peter J. Attar ◽  
Earl H. Dowell ◽  
John R. White
Keyword(s):  
Limit Cycle ◽  
Structural Model ◽  
Delta Wing ◽  
High Fidelity ◽  
Limit Cycle Oscillations

Delta Wing with Store Limit-Cycle-Oscillation Modeling Using a High-Fidelity Structural Model

2008 ◽  
Vol 45 (3) ◽  
pp. 1054-1061 ◽  
Author(s):  
Peter J. Attar ◽  
Earl H. Dowell ◽  
Deman Tang
Keyword(s):  
Limit Cycle ◽  
Structural Model ◽  
Delta Wing ◽  
Limit Cycle Oscillation ◽  
High Fidelity ◽  
Cycle Oscillation

Efficient Uncertainty Propagation for High-Fidelity Simulations With Large Parameter Spaces: Application to Stiffened Plate Buckling

2018 ◽  
Vol 3 (1) ◽  
Author(s):  
Ken Nahshon ◽  
Nicholas Reynolds ◽  
Michael D. Shields
Keyword(s):  
Uncertainty Quantification ◽  
Structural Model ◽  
Uncertainty Propagation ◽  
Computational Cost ◽  
Small Sample ◽  
Simplified Model ◽  
High Fidelity ◽  
Stiffened Plate ◽  
Structural Investigations ◽  
Subject Matter Expertise

Uncertainty quantification (UQ) and propagation are critical to the computational assessment of structural components and systems. In this work, we discuss the practical challenges of implementing uncertainty quantification for high-dimensional computational structural investigations, specifically identifying four major challenges: (1) Computational cost; (2) Integration of engineering expertise; (3) Quantification of epistemic and model-form uncertainties; and (4) Need for V&V, standards, and automation. To address these challenges, we propose an approach that is straightforward for analysts to implement, mathematically rigorous, exploits analysts' subject matter expertise, and is readily automated. The proposed approach utilizes the Latinized partially stratified sampling (LPSS) method to conduct small sample Monte Carlo simulations. A simplified model is employed and analyst expertise is leveraged to cheaply investigate the best LPSS design for the structural model. Convergence results from the simplified model are then used to design an efficient LPSS-based uncertainty study for the high-fidelity computational model investigation. The methodology is carried out to investigate the buckling strength of a typical marine stiffened plate structure with material variability and geometric imperfections.

Industrial Challenges in Large Thermally Enabled Structural Whole Engine Models

2020 ◽  
Author(s):  
Michelle Tindall ◽  
Akin Keskin ◽  
Andrew Layton
Keyword(s):  
Gas Turbine ◽  
High Performance ◽  
Structural Model ◽  
System Level ◽  
High Fidelity ◽  
Mapping Procedure ◽  
Engine Model ◽  
Component Design ◽  
Design Changes ◽  
Significant Step

Abstract Understanding gas turbine design at a system level presents a difficult challenge. Accurate predictions of gas turbine behaviour before whole engine tests are completed are invaluable in preventing costly design changes in the latter stages of the design life cycle. In this study a high fidelity whole engine model has been built — specifically, a thermally enabled structural model. This model can predict component displacements up to system level interactions across the whole engine. Knowledge from such a model can feed into multiple design areas contributing to performance, component design and structural understanding but can also be used to influence physical testing. There are clear benefits in building such high fidelity models but also many challenges that need to be addressed, namely solver type, geometry interrogation, meshing, solver capability, computational power and finally, processing and validation of output data. Additionally, different applications have been used for thermal and structural modelling in order to utilise best capabilities in thermal and contact modelling but also enable scalability on high performance computing. However, utilising two different solvers involves meshes being tailored for each solver type but also introduces additional complexity of transferring information between the two models used. The paper will discuss the challenges and analysis methodologies used to thermally solve the whole engine cycle, the mapping procedure to translate thermal data to a structural model, and the approach taken to solve the very large simulation model explicitly at a chosen condition to a pseudo-steady state. In order to validate the simulation results, a vast amount of time has been spent to compare the results to existing test data. As model validation is a significant step in simulation to gain credibility of the results, a comparison of the predicted component displacements will be shown to X-ray data from a whole engine test. Results and limitations of this testing capability such as influence of engine vibration, shutter speed and noise in the data will be discussed and recommendations provided to improve accuracy of the results.

High-Fidelity Computational Simulation of Nonlinear Fluid-Structure Interactions

Volume 3 ◽  
2004 ◽  
Author(s):  
Raymond E. Gordnier ◽  
Miguel R. Visbal
Keyword(s):  
Delta Wing ◽  
Computational Simulation ◽  
Nonlinear Finite Element ◽  
Navier Stokes ◽  
High Fidelity ◽  
Fluid Structure Interactions ◽  
Computational Framework ◽  
Fluid Structure ◽  
Physical Phenomena ◽  
Nonlinear Fluid

This paper reviews recent efforts to demonstrate a flexible computational framework for developing a high-fidelity, non-linear aeroelastic solver. A subiteration strategy is adopted to achieve implicit coupling between the computational fluid dynamics and the structural codes. The specific solver presented couples a well-validated, full Navier-Stokes code with a nonlinear finite element plate model. The versatility of the approach is shown by applications to several types of fluid-structure interaction problems including: panel flutter, delta wing LCO and delta wing buffet. The computational results are analyzed to elucidate the relevant physical phenomena involved in these complicated nonlinear fluid-structure interactions. This framework is extendible to other multidisciplinary problems where two or more disciplines may need to be coupled.

scholarly journals Seismic damage simulation in urban areas based on a high-fidelity structural model and a physics engine

2013 ◽  
Vol 71 (3) ◽  
pp. 1679-1693 ◽  
Author(s):  
Zhen Xu ◽  
Xinzheng Lu ◽  
Hong Guan ◽  
Bo Han ◽  
Aizhu Ren
Keyword(s):  
Urban Areas ◽  
Structural Model ◽  
Seismic Damage ◽  
High Fidelity ◽  
Physics Engine ◽  
Damage Simulation

scholarly journals Challenges of fully-coupled high-fidelity ditching simulations

2018 ◽  
Vol 233 ◽  
pp. 00020
Author(s):  
Maximilian Müller ◽  
Malte Woidt ◽  
Matthias Haupt ◽  
Peter Horst
Keyword(s):  
Structural Model ◽  
Mass Effect ◽  
Computational Effort ◽  
Coupling Scheme ◽  
High Fidelity ◽  
Reduced Order ◽  
Partitioned Approach ◽  
Numerical Simulation Methods ◽  
Hydrodynamic Effects ◽  
Fully Coupled

An important element of the process of aircraft certification is the demonstration of the crashworthiness of the structure in the event of an emergency landing on water, also referred to as ditching. Novel numerical simulation methods that incorporate the interaction between fluid and structure open up a promising way to model ditching in full scale. This study presents a numerical framework for the simulation of ditching on a high–fidelity level. A partitioned approach that combines a finite volume hydrodynamic fluid solver as well as an finite element structural solver is implemented using a Python-based distributed coupling environment [1]. High demands are placed both on the fluid and the structural solver. The fluid solver needs to account for hydrodynamic effects such as cavitation in order to correctly compute the ditching loads acting on the aircraft structure. In the structural model, the highly localized damage induces nonlinearities and large differences in model scale. In order to reduce the computational effort a reduced order model is used to model the failure of fuselage frames. The fluid-structure coupling requires an explicit coupling scheme. It is shown that the standard Dirichlet-Neumann approach exhibits unstable behaviour if a strong added-mass effect is present, as is the case in aircraft ditching. This indicates a need for methods other than the standard Dirichlet-Neumann approach [2].

scholarly journals Challenges of Fully-Coupled High-Fidelity Ditching Simulations

Aerospace ◽  
2019 ◽  
Vol 6 (2) ◽  
pp. 10 ◽  
Author(s):  
Maximilian Müller ◽  
Malte Woidt ◽  
Matthias Haupt ◽  
Peter Horst
Keyword(s):  
Structural Model ◽  
Mass Effect ◽  
Computational Effort ◽  
Full Scale ◽  
Scale Model ◽  
High Fidelity ◽  
Multi Scale ◽  
Coupling Approach ◽  
Numerical Simulation Methods ◽  
Fully Coupled

An important element of the process of aircraft certification is the demonstration of the crashworthiness of the structure in the event of an emergency landing on water, also referred to as ditching. Novel numerical simulation methods, that incorporate the interaction between fluid and structure, open up a promising way to model ditching in full scale. This study focuses on two main issues of high-fidelity ditching simulations: the development of a suitable fluid-structure coupling framework and the generation of the structural model of the aircraft. The first issue is addressed by implementing a partitioned coupling approach, which combines a finite volume hydrodynamic fluid solver as well as a finite element structural solver. The developed framework is validated by means of two ditching-like experiments, which consider the drop test of a rigid cylinder and a deformable cylindrical shell. The results of the validation studies indicate that an alternative to the standard Dirichlet-Neumann partitioning approach is needed if a strong added-mass effect is present. For the full-scale simulation of aircraft ditching, structural models become more complex and have to account for damage. Due to its high localization, the damage creates large differences in model scale and usually entails severe non-linearities in the model. To address the issue of increasing computational effort for such models, the process of developing a multi-scale model for the simulation of the failure of fuselage frames is presented.

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