United Aircraft (Russia)

As a critical energy component in electric vehicles, energy storage systems, and other applications, the accurate estimation of the State of Health (SOH) of lithium-ion batteries is crucial for performance optimization and safety assurance. To this end, this paper proposes a hybrid model named Transformer–KAN, which integrates Transformer architecture with Kolmogorov–Arnold Networks (KANs) for precise SOH estimation of lithium-ion batteries. Initially, five health features (HF1–HF5) strongly correlated with SOH degradation are extracted from the historical charge–discharge data, including constant-voltage charging duration, constant-voltage charging area, constant-current discharging area, temperature peak time, and incremental capacity curve peak. The effectiveness of these features is systematically validated through Pearson correlation analysis. The proposed Transformer–KAN model employs a Transformer encoder to capture long-term dependencies within temporal sequences, while the incorporated KAN enhances the model’s nonlinear mapping capability and intrinsic interpretability. Experimental validation conducted on the NASA lithium-ion battery dataset demonstrates that the proposed model outperforms comparative baseline models, including CNN–LSTM, Transformer, and KAN, in terms of both RMSE and MAE metrics. The results indicate that the Transformer–KAN model achieves superior estimation accuracy while exhibiting enhanced generalization capabilities across different battery instances, indicating its strong potential for practical battery management applications.

The growing global energy sector demands battery systems with enhanced stability and operational safety. Aqueous zinc-ion energy-storage-integrated batteries have emerged as potential candidates due to their high theoretical capacity and environmentally benign aqueous electrolytes. Despite continuous advances in battery-related technologies, current systems still face challenges in balancing mechanical robustness with energy density for structural energy-storage applications. To address these limitations, we developed a triangular stabilized ether–water–epoxy hybrid structural membrane system by incorporating a tetraglyme additive into zinc trifluoromethanesulfonate solution, which was infused into a porous epoxy resin membrane. This ether–water–epoxy hybrid structural membrane system effectively inhibits zinc dendrite formation while exploiting its antiswelling characteristics to preserve mechanical integrity (swelling ratio <2% after 48 h immersion and maintained a tensile strength of 6.8 MPa). The optimized battery demonstrated exceptional cycling stability (>880 h at 1.0 mA cm–2 and 1.0 mAh cm–2) while achieving 83.2% capacity retention over 400 cycles at 1 C. Furthermore, the structural energy device retained >80% capacity after 100 cycles under 0.5 C while withstanding bending stresses exceeding 400 MPa. Remarkably, the structural energy device achieved complete in situ full mechanical and electrochemical recyclability under 300 MPa bending stress, demonstrating a great potential for application in the field of both sustainable materials and structural energy-storage devices.

Nonlinear aeroelastic simulations are benchmarked against wind tunnel experiments of a very flexible wing. In the simulations, sectional force corrections are employed to capture low-Reynolds-number effects and the static lift deficiency due to the onset of flow separation. With these corrections, both the static and dynamic wing deformation predictions match the experiments well (2% and 6% error, respectively). Furthermore, a simulation of the unsteady inflow to the Delft-Pazy wing that is produced by the gust vanes in the wind tunnel is explored as an alternative to a frozen gust model. Results indicate a considerable influence of the wing’s presence on the gust velocity that was measured upstream of the wing in the wind tunnel experiment. The structural response, however, differs only slightly when using the two different gust models. This confirms that the uniform gust is still a valid assumption for moderately large deflections (up to 24% of the wingspan in this work). Finally, geometrically nonlinear effects are assessed and found to be relevant in the simulations because of the nonlinear aeroelastic equilibrium, but not because of the gust excitation.

This research introduces a charge-enhanced encoding module within the AisNet multifeature fusion framework, demonstrating superior force error accuracy and cross-model transferability, and achieving in state-of-the-art performance on the SN2 dataset. Compared with the original AisNet, the addition of the Coulomb matrix enables AisNet-C with ternary features to maintain its leading performance in all feature dimensions. Through t-SNE and PCA analysis, long-range Coulomb interaction effectively enhances global environmental resolution, forming a synergistic relationship with other features. The performance of the AisNet-C is optimal at a dimension larger than 60, which is related to the accuracy of the ACSF fitting. Particularly, the PAINN model demonstrated the best compatibility with the enhanced module, resulting in the SOTA result of 0.00423 eV/Å and reducing the mean error over by 41.8% compared to PhysNet's benchmark. The key to PaiNN's success lies in the multimodule cooperation, which maintains intraclass atomic resolution while bringing different atom types closer together, thus forming a more compact feature space. Our plug-and-play encoding module can not only efficiently utilize multiple descriptors through feature decoupling, but also has the potential to be applied to a wider range of model architectures, providing new ideas for realizing physically informed machine learning force fields.

Abstract This paper presents an open virtual test case of an Open Fan geometry. The Open Fan is the newest and most promising un-ducted aero-engine concept. It is expected to be quieter and mechanically less complex than a Counter-Rotating Open Rotor (CROR) and, at the same time, deliver a similar level of fuel burn. The fuel burn and emissions improvements with respect to an Ultra-High Bypass Ratio (UHBR) ducted fan are expected to be very significant. A challenge will be to minimize the acoustic impact. Nowadays, there is no available state-of-the-art Open Fan design in the public domain, or even a state-of-the-art CROR geometry, that can be used by researchers to conduct simulations independently. A realistic industrially-driven Open Fan virtual test case has been released by the PANDORA project consortium. The key outcome of the PANDORA project is an estimate of the improvements delivered by the Open Fan configuration with respect to a CROR in terms of noise, performance and emissions. The added value of having a realistic design is that it drives naturally the research in the correct direction and provides the range of parameters in which the physics must be properly solved and understood. In this work, a new Open Fan geometry will be delivered together with the pitch settings at different operating conditions. The aerodynamics of an Open Fan is more demanding than that of a CROR. In fact, the Open Fan presents a higher aerodynamic loading and Mach number for the same thrust. The aerodynamic performance of the Open Fan configuration is obtained using RANS simulations. This type of simulations is also useful to assess the influence of design changes on the Open Fan performance. RANS simulations have been successfully used to compute the aerodynamic loading, thrust and efficiency at different operating conditions.

Abstract Aircraft engine manufacturers develop new combustion technologies to comply with stricter regulations on pollutant emissions such as nitrous oxides (NOx) or soots. Staged systems coupled with lean premixed combustion show promising prospects to reduce these emissions through correct mixing of the fuel ahead of the combustion chamber but are more prone to thermo-acoustic instabilities. Hence guaranteeing the stability over the entire operating range is more challenging. The thermo-acoustic behaviour of lean staged systems is investigated experimentally on the laboratory-scale BIMER combustor, an atmospheric pressure test rig composed of a two-stage swirled injector reminiscent of industrial systems and fuelled with liquid dodecane. It uses a simplex atomizer in the pilot stage, multipoint injection in the main stage and can be externally forced using a siren device located upstream of the injector. This study focuses on the thermo-acoustic behaviour of the pilot stage of the BIMER combustor. Flame response to acoustic perturbations at different pre-heating temperatures (ranging from 383 to 473K) is assessed. To this end, Flame Describing Functions (FDF) are measured using acoustic forcing, a photomultiplier with an OH* filter for heat release rate fluctuation measurements and the multi-microphone method to determine acoustic velocity fluctuations. An acoustic network model of the combustor using the L-ζ model for the injector is used to compute acoustic velocity fluctuations at the base of the flame. This model is parameterised using only the burner geometrical configuration, with no tuning to fit reference experimental data. The accuracy of the model prediction is discussed. Measurements also display flame shape bifurcations from V to Tulipshape flames generated by acoustic forcing at certain frequencies and amplitudes. High-speed imaging of flame chemiluminescence in the visible range is used to describe these bifurcations. The role of acoustic forcing is highlighted through phase-averaging.

Aerodynamics is a fundamental discipline in the field of aviation, as it governs the airflow around an aircraft, enabling lift generation. The design and construction of aircraft wings are critical, as they directly impact the aircraft's stability and lift efficiency. Thus, aerodynamics plays a pivotal role in the performance, functionality, and overall design of aircraft. With advancements in modern aviation, continuous improvements are being made in the design and configuration of wing models. To analyze the aerodynamic characteristics of an aircraft wing, the airflow distribution method is commonly employed, one of which includes the use of vortex generators. This study investigates the effects of adding triangular vortex generators to a NACA 0012 airfoil, utilizing the smoke generator method in a straight arrangement. The experiments were conducted in an open-circuit wind tunnel with an airflow velocity of 5 m/s. The angles of attack tested were 0°, 4°, 8°, 10°, 15°, 17°, and 20°. The vortex generators were positioned 20% of the chord length from the leading edge of the airfoil. The experimental results demonstrate that the addition of triangular vortex generators increases the distance to the furthest point of separation and enhances the transition point on the airfoil. The aerodynamic performance of the airfoil was evaluated based on the observed airflow patterns around the airfoil, which showed notable differences compared to the airfoil without vortex generators.

The development of multimaterial topology optimization offers significant advancements in the design of lightweight aerospace structures. A three-field multimaterial topology optimization method with a material selection function under a mass constraint is developed. By integrating a multimaterial linear interpolation model with floating projection techniques, design variables are refined to the expected 0/1 level, ensuring accurate smooth design. The approach demonstrates smooth convergence even when applied to more than three material phases, producing optimized structures with distinct material boundaries and interfaces. A case study of the aircraft engine pylon design is presented, utilizing real material properties, including Poisson’s ratio, to meet lightweight design requirements. The requirement of lightweight design is realized by introducing effective lightweight materials and automatically adjusting the distribution and volume fraction of materials. Additionally, the three-field density representation technique is applied to improve the optimization efficiency and is extended to design considering manufacturing uncertainty. The robust manufacturing multimaterial structure is designed with the potential for manufacturing errors in mind. It can provide valuable guidance for multimaterial lightweight design of aerospace structures.