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Real-Time Aerodynamic Load Estimation for Hypersonics via Strain-Based Inverse Maps

AIAA JOURNAL 2025年第1期63卷 91-101页

作者： Pham, Julie V. Ghattas, Omar Clemens, Noel T. Willcox, Karen E. Univ Texas Austin Dept Aerosp Engn & Engn Mech Austin TX 78712 USA Univ Texas Austin Oden Inst Computat Engn & Sci Walker Dept Mech Engn Austin TX 78712 USA

This work develops an efficient real-time inverse formulation for inferring the aerodynamic surface pressures on a hypersonic vehicle from sparse measurements of the structural strain. The approach aims to provide real-time estimates of the aerodynamic loads acting on the vehicle for ground and flight testing, as well as guidance, navigation, and control applications. Specifically, the approach targets hypersonic flight conditions where direct measurement of the surface pressures is challenging due to the harsh aerothermal environment. For problems employing a linear elastic structural model, the inference problem can be posed as a least-squares problem with a linear constraint arising from a finite element discretization of the governing elasticity partial differential equation. Due to the linearity of the problem, an explicit solution is given by the normal equations. Precomputation of the resulting inverse map enables rapid evaluation of the surface pressure and corresponding integrated quantities, such as the force and moment coefficients. The inverse approach additionally allows for uncertainty quantification, providing insights for theoretical recoverability and robustness to sensor noise. Numerical studies demonstrate the estimator performance for reconstructing the surface pressure field, as well as the force and moment coefficients, for the Initial Concept 3.X (IC3X) conceptual hypersonic vehicle.

关键词： Aerodynamic Coefficients Aircraft Operations and Technology Onboard Sensors Uncertainty Quantification Hypersonic Vehicles Guidance, Navigation, and Control Systems structural modeling and simulation Mechanical Properties Flight Testing Hypersonic Aircraft

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Framework of Physically Consistent Homogenization and Multiscale modeling of Shell Structures

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AIAA JOURNAL 2025年第1期63卷 260-273页

作者： Zhang, Zewei Lu, Zhiyuan Yang, Yu Dong, Leiting Atluri, Satya N. Beihang Univ Sch Aeronaut Sci & Engn Natl Key Lab Strength & Struct Integr Beijing 100191 Peoples R China Tianmushan Lab Hangzhou 310023 Peoples R China Aircraft Strength Res Inst China Natl Key Lab Strength & Struct Integr Xian 710065 Shaanxi Peoples R China Texas Tech Univ Dept Mech Engn Lubbock TX 79409 USA AIAA Reston VA 20191 USA

A framework of physically consistent homogenization and multiscale modeling (PCHMM) for reduced-order analysis of plate/shell structures is developed in this paper. To address the inapplicability of conventional periodic boundary conditions and Hill's condition involved in homogenization of shear-deformable shell structures, the paper proposes physically consistent boundary conditions and modified Hill's condition for plate/shells. Unlike the PCHMM method for beams, considering the contradiction between high-order displacement fields induced by shear forces and low-order kinematic assumptions, additional constraints are applied to the plate/shell structure sectional strains during the solution of perturbation fields. The correctness and effectiveness of the proposed plate/shell PCHMM framework and method are verified by typical numerical examples. The proposed theory can also be conveniently embedded into commercial finite element software for homogenization and multiscale analysis of structures such as microscale metamaterials like lattice plates and large complex structures like aircraft fuselage sections.

关键词： structural modeling and simulation Shell Structures Homogenization Multiscale modeling Boundary Condition

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Preflight and Postflight Thermal/structural Analysis of BOLT-2: The Holden Mission

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JOURNAL OF SPACECRAFT AND ROCKETS 2024年第5期61卷 1204-1218页

作者： Wheaton, Bradley Dufrene, Aaron Johns Hopkins Univ Appl Phys Lab 11100 Johns Hopkins Rd Laurel MD 20723 USA CUBRC Aerothermal Aeroopt Evaluat Ctr 4455 Genesee StSuite 106 Buffalo NY 14225 USA

BOLT-2: The Holden Mission, a follow-on to the BOLT experiment, was designed to measure the characteristics of turbulent flow in the hypersonic flight regime. This paper summarizes preflight transient thermal and structural analyses for the predicted flight trajectories that led to the selection of suitable materials for the flight experiment. Following the successful flight in March 2022, the preflight analysis methods, along with temperature measurements from the flight, were used to conduct a postflight thermal analysis based on the as-flown trajectory that attempted to match the flight data. Conservatism in the preflight design analysis was compared to the flight measurements. Databases of computed laminar and turbulent heating were generated as part of this effort that can aid in future analysis of the experimental data. The effects of modeling transitional heating during ascent were quantified when compared to a fully turbulent heating assumption. A set of estimated three-dimensional surface temperature distributions have been computed and were found to be a good match to the available flight data. Postflight structural modeling was used to estimate the differential thermal expansion at the nosetip/frustum joint interface.

关键词： Thermal structural Analysis Thermal modeling and Analysis structural modeling and simulation Computational Fluid Dynamics Hypersonic Aerothermodynamics Hypersonic Aerodynamics Flight Test Sounding Rockets Boundary Layer Transition Turbulence

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Making Finite Element modeling Choices Using Decision-Tree-Based Fuzzy Inference System

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AIAA JOURNAL 2023年第3期61卷 1349-1365页

作者： Palwankar, Manasi P. Kapania, Rakesh K. Hammerand, Daniel C. Virginia Polytech Inst& State Univ Dept Aerosp & Ocean Engn Blacksburg VA 24060 USA M4 Engn Inc Long Beach CA 90807 USA

This work presents a decision-tree-based Fuzzy Inference System (FIS) for making optimal choices in the development of reduced-order finite element (FE) models, in our case, shell-solid multifidelity models. FE analysis is widely used to simulate the real-world response of complex engineering structures and requires a high level of expertise for making a priori modeling decisions. Many times, these decisions are quite subjective in nature and lead to significant analyst-to-analyst variability, which in turn leads to considerable differences in engineering solutions. An expert system that recommends optimal modeling choices would notably reduce such variability. Expert systems use a knowledge base, developed by a subject matter expert, which is not always easy for complex structures. This work assesses the potential of interpretable machine learning (decision trees) to create data-driven rules that could be used by a FIS to make modeling choices for a multifidelity T-joint model. Specifically, the FIS takes the structural geometry and desired accuracy as inputs and infers the optimal two-dimensional/three-dimensional topology distribution. Once developed, the FIS is able to provide real-time optimal choices along with interpretability that fosters analysts' confidence. Potential improvements to the presented framework that can enable its application to complex and nonlinear problems are discussed.

关键词： Support Vector Machine Artificial Intelligence structural modeling and simulation Expert System Finite Element modeling Fuzzy Logic Decision Trees Fuzzy Inference System Shell-Solid Coupling Stiffened Shells

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Buckling and Fundamental Frequency Optimization of Tow-Steered Composites Using Layerwise structural Models

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AIAA JOURNAL 2023年第9期61卷 4149-4163页

作者： Sanchez-Majano, Alberto Racionero Pagani, Alfonso Polytech Univ Turin Dept Mech & Aerosp Engn I-10129 Turin Italy

Variable-angle-tow (VAT) composite laminates can eventually improve the mechanical performance of lightweight structures by taking advantage of a larger design space compared to straight-fiber counterparts. Here, we provide a scalable low- to high-fidelity methodology to retrieve the tow angles that maximize the buckling load and the fundamental frequency of VAT plates. A genetic algorithm is used to solve the optimization problem in which the objective function is mimicked using a surrogate model. Both unconstrained and manufactured-constrained problems are solved. The surrogates are built with outcomes from numerical models generated by means of the Carrera unified formulation, which enables to obtain straightforwardly different degrees of accuracy by selecting the order of the structural theory employed. The results show both the validity and flexibility of the proposed design approach. It is shown that, although the optimal design fiber angle orientations are consistently similar, discrepancies in the prediction of the buckling load or fundamental frequency can be found between high-fidelity layerwise and low-to-refined equivalent-single-layer models, of which classical laminated plate or first-shear deformation theories are degenerate examples.

关键词： Buckling Analysis structural modeling and simulation Fiber Volume Fraction Genetic Algorithm Finite Element Method Optimization Algorithm Mechanical and structural Vibrations Composite Structures Variable Stiffness Composites Variable-angle Tow

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Uncertainty Quantification of the ONERA 7A Rotor Performance and Loads Using Comprehensive Analysis

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JOURNAL OF AIRCRAFT 2023年第4期60卷 1141-1159页

作者： Khurana, Manas El Din, Itham Salah Yeo, Hyeonsoo Sci & Technol Corp Ames Res Ctr Moffett Field CA 94035 USA ONERA French Aerosp Lab Dept Aerodynam Aeroelast & Acoust F-92190 Meudon France US Army Combat Capabil Dev Command Aviat & Missile Ctr Ames Res Ctr Moffett Field CA 94035 USA

Quantification of blade stiffness uncertainties and sensitivities on rotor power and structural loads for the ONERA 7A rotor is established using the U.S. Army and ONERA rotorcraft comprehensive analysis tools. A stochastic-based approach is implemented to generate probabilistic bounds of the response outputs, including rotor performance and loads due to uncertainties in blade stiffness using 1) a Monte Carlo approach coupled directly with U.S. Army's rotorcraft comprehensive toolset, and 2) a surrogate of ONERA's rotorcraft comprehensive analysis solver using polynomial chaos expansions to efficiently predict the response outputs. The analysis showed that uncertainties in blade torsion, flap, and lag stiffnesses impact the predicted rotor power by a quantifiable amount. Significant uncertainties in peak torsion, flap, and chord bending moments are also confirmed. The sensitivities of the stiffness properties on response outputs using Sobol indices are also studied. The results show that total required power is exclusively sensitive to variability in torsion stiffness with no interaction effects with flap and lag stiffnesses. Sensitivities due to independent parameter effects and by combining with other parameters on peak structural loads are also examined. The analysis demonstrates the merits of integrating a stochastic, data-driven approach for uncertainty and sensitivity analyses in rotorcraft aeromechanics predictions.

关键词： structural Analysis Rotorcrafts structural modeling and simulation Continuous Probability Distributions Mathematical Analysis Polynomial Chaos Expansion Uncertainty Quantification Sensitivity Analysis Comprehensive Analysis Monte Carlo simulations

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Aeroelastic Analysis Using Deforming Cartesian Grids

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AIAA JOURNAL 2023年第3期61卷 1095-1108页

作者： Boschitsch, Alexander H. Whitehouse, Glen R. Continuum Dynam Inc Ewing NJ 08558 USA

Ongoing work in air-vehicle design illustrates the potential of advanced concepts to provide significant improvements in efficiency;but with their incorporation of lightweight flexible structures, such configurations may require active control systems to ensure reliability and safety. However, many contemporary analysis methods are inefficient for aeroelastic analysis and design of such configurations. This paper describes the development of a new approach that automates the geometry setup, mesh generation, and assembly of fluid-structural coupling interfaces to enable efficient aeroelastic and aeroservoelastic analysis of advanced concepts. The core elements for this approach are a cut-cell Cartesian grid-based computational fluid dynamics solver, a nonlinear beam element structural model, a conservative fluid-structural interface treatment, and the formulation and implementation of a new deforming grid capability within the cut-cell Cartesian grid solver. Herein, emphasis is on this latter component with detailed description given of the mesh motion strategy, evaluation of fluxes and structural loads at the surface, and computation of geometrical properties such as cell volume, directed face areas, centroids, and motion-induced fluxes for deforming Cartesian grids required to advance the flow states. Aeroelastic simulations exercising the capability show favorable agreement with data and predictions in the literature for subsonic and supersonic applications.

关键词： Aeroelastic Analysis structural modeling and simulation Computational Fluid Dynamics Unstructured Grid structural Displacement Supersonic Aircraft Flexible and Active Structures Aerodynamic Damping Cartesian Grids Deforming Grids

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Optimization and Testing of DC Electromagnetic Pump for Liquid Metal Space Use

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JOURNAL OF PROPULSION AND POWER 2024年第5期40卷 717-728页

作者： Qiao, Mengwen Zhou, Yixin Liu, Guilin Deng, Zhongshan Sheng, Lei Wang, Lei Wang, Qian Liu, Jing Tech Inst Phys & Chem Chinese Acad Sci Key Lab Cryogen Sci & Technol Beijing 100190 Peoples R China Univ Chinese Acad Sci Sch Future Technol Beijing Peoples R China Tsinghua Univ Sch Med Dept Biomed Engn Beijing Peoples R China

Driving a liquid metal via an electromagnetic pump (EMP) is becoming increasingly important with its many emerging cutting-edge uses. The end losses associated with the EMP generally play a core role in dominating device performance. In this study, we explored the effects of electrode width, number of insulating strips, and pump width on the end loss through theoretical analysis and numerical simulations. The optimization results indicate that reducing electrode width would improve EMP performance. Adding insulation strips enhances the magnitude and uniformity of effective current density but raises hydraulic losses. A smaller pump width achieves a stronger static head, while a larger pump width outputs a higher flow rate. Furthermore, 3D printing technology was employed for rapid integrated processing of the pump body. Detailed performance evaluations and reliability tests were carried out on the EMP. With the design optimized so as to minimize the end losses, an EMP for space experiments has been successfully developed, which will eventually be flown on the China's space station. Overall, the feasibility of fast, low-cost manufacturing of high-reliability, compact EMP with the assistance of numerical simulation and 3D printing technology was demonstrated. It provides an alternative option for driving metallic fluid for various future space needs.

关键词： Space Experiments Reynolds Averaged Navier Stokes Electrical Resistance Fluid Mechanics structural modeling and simulation Gauss's Law for Magnetism 3D Printing Numerical simulation Thermal Measurement Pump Performance

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Approach to Aircraft Handling Qualities Prediction

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JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 2024年第11期47卷 2397页

作者： Lampton, Amanda Klyde, David Musso, Dakota Mitchell, David G. Rhinehart, Matthew Syst Technol Inc Hawthorne CA 90250 USA Virgin Galact Flight Controls Mojave CA USA Mitchell Aerosp Res Long Beach CA 90806 USA Naval Air Syst Command NAS Patuxent River Maryland NY 20670 USA

For the decades that followed the publication of the Cooper-Harper report that formalized a standard and universally recognized handling qualities pilot rating scale, researchers have sought to correlate pilot compensation-as well as physical and mental workload-with the assigned rating. A quantitative correlation remains elusive. In recent years, new physiological measurement devices have been developed that, together with software processing tools, can provide accurate measures of psychophysiological measures, including cognitive workload, distraction, and high/low engagement, based on electroencephalogram and electrocardiogram measures (i.e., brain waves and heart rate variability). The pilot compensation referred to in the Cooper-Harper scale is also a function of task performance measures that reflect aircraft characteristics and inceptor activity that reflects upon physical workload. Using a new piloted simulation test database generated in Manned Flight Simulator's containerized rotary-wing simulator with 10 experienced test pilots, a machine-learning-based software algorithm that integrates a disparate mix of pilot-vehicle system, physiological, and task performance measures was used to further develop an approach to predict handling qualities levels and ratings.

关键词： Handling Qualities Aircrafts Support Vector Machine Test Pilots Flight Simulators Rotary Wing Algorithms and Data Structures structural modeling and simulation Generative Adversarial Network Aircraft Flight Control System

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Effect of Model Fidelity on High-Speed Aeroelastic Behavior of a Cantilever Plate

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AIAA JOURNAL 2024年第10期62卷 3881-3892页

作者： Thayer, Jordan D. McNamara, Jack J. Ohio State Univ Columbus OH 43210 USA

Turbulence, flow separation, and shock dynamics challenge the modeling and analysis of high-speed aeroelastic behavior. Motivated by this, the importance of modeling the fidelity of the flow is explored in the aeroelastic response of a cantilever plate in an Ma=2.0 separating turbulent flow using unsteady Reynolds-averaged Navier-Stokes (URANS) and URANS-enriched local piston theory (LPT). structural modeling assumptions are also evaluated using both linear and nonlinear representations. Close agreement in the predicted aeroelastic steady state is observed. However, large discrepancies in the dynamic aeroelastic response predictions are found and ultimately linked to the neglect of deformation-induced cavity pressure fluctuations and dynamic flow separation in the LPT model. Interestingly, the dynamic flow separation induces a fluid-driven limit cycle oscillation in the postflutter regime. Furthermore, structural nonlinearity is not found to have a strong impact on the conditions and configurations considered.

关键词： Unsteady Reynolds Averaged Navier Stokes Aeroelastic Response Prediction structural modeling and simulation Aerodynamic Force Shockwave Boundary Layer Interaction Piston Theory structural Dynamics Supersonic Boundary Layers Computational Fluid Structure Interaction Fluid Structure Interaction

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