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High-Order Harmonic Balance Vortex Lattice Method for Nonlinear Aeroelastic Limit Cycle Oscillations
Full text linkThis paper presents a full frequency‐domain framework for nonlinear aeroelastic analysis that couples a high‐order harmonic‐balance (HB) structural solver with a recently developed HB Vortex‐Lattice method (HB‐VLM) for unsteady aerodynamics. Embedding this coupled solver within a numerical‐continuation algorithm enables efficient tracing of self‐sustained limit‐cycle oscillations (LCOs) and their associated bifurcations without resorting to costly time‐domain integration. The approach is demonstrated on canonical three‐degree‐of‐freedom wing sections, where comparisons against time‐marching solutions confirm that high‐order HB captures rich harmonic content and bifurcation behavior. Our results highlight the method's accuracy and robustness even in strongly nonlinear regimes, along with paving the way for rapid medium‐fidelity aeroelastic analysis of complex wings in early‐stage aircraft design
Full Potential Calculations With Immersed Boundary Ghost-Cell Method
No full textTo address the need to simplify the grid generation process while enabling affordable multidisciplinary aerodynamic simulations, this paper presents a novel medium-fidelity unstructured finite volume Full Potential method incorporating an immersed boundary (IB) formulation with ghost cells. The development begins with the classical body-fitted (BF) Full Potential approach, followed by the integration of the IB ghost-cell methodology. Results obtained using the new approach are compared with those from traditional Full Potential and Euler BF methods. The agreement between the solutions demonstrates that the proposed approach offers sufficient accuracy for use in multidisciplinary contexts. Additionally, computational speedups are observed for certain configurations, showcasing significant reduction in computational cost
Fast investigation of control interaction risks in PV parks using eigenvalue analysis in Modelica
No full textEffects of triaxial sample scaling on the mechanical behavior of alluvial gravels
Full text linkABSTRACT: In practical engineering, mechanical characterization of coarse gravels is usually performed on small-scale specimens, where the maximum particle size is limited to fit the material in standard testing devices. This implies altering the original particle size distribution, which is known to influence the stress–strain behavior. However, most research on grading effects has been done after comprehensive testing on sands, and the impact of small-scaling on gravelly soils is still poorly understood. This paper presents an experimental study on the shearing response of coarse soil at different specimen scales. The main objective is to assess the impact of small-scaling methods on the stress–strain behavior of coarse alluvial soils. Scalping grading and truncation techniques were used to prepare scaled specimens. Several tests were performed using triaxial cells with specimens of 100, 150, and 800 mm diameter. The analyses indicate that volumetric dilatancy strongly decreases with specimen size, while the secant strain modulus and peak shear strength slightly increase in larger specimens. Differences are mainly related to particle size distributions and packing properties. The article discusses practical insights into the effects of small-scaling variations and their implications for characterizing gravelly materials
