A review on thermal issues in Li-ion battery and recent advancements in battery thermal management system

On using neural networks in UAV structural design for CFD data fitting and classification

Block oriented models are recurrently employed to describe the dynamic characteristics of nonlinear systems. This paper adopts an efficacious block-oriented model called cascaded Wiener-Hammerstein (W-H) structure to model a nonlinear system. The parameters of the W-H model are identified using a nature-inspired evolution algorithm-supported Kalman filter (KF). In the proposed technique, the utility of the employed optimisation algorithm named Harris Hawks optimiser (HHO) is to acquire the optimal global solution of initial state KF parameters for the W-H system identification problem. Then, the conventional KF algorithm utilises these optimised KF parameters to beget the near-global estimated W-H system parameters. The effectiveness of the proposed HHO-based KF algorithm is verified through a comparison study with other variants of particle swarm optimisation (PSO) and harmony search (HS) algorithms-supported KF methods on two numerical W-H problems with different nonlinearity levels and two practical benchmark plants, namely, real electronic diode switching network and flutter clearance of F-18 systems research aircraft. The simulation results ensure that the proposed HHO-KF approach offers significantly improved results over other competing methods in terms of various well known standard metrics. The hypothesis test verifies the stability and consistency of the proposed identification method. Moreover, the proposed approach provides a faster convergence rate and the lowest estimation precision compared with other reported techniques. 

Optimal design of cascaded Wiener-Hammerstein system using a heuristically supervised discrete Kalman filter with application on benchmark problems

Traditional commercial aircraft design attempts to improve performance and reduce operating costs by minimizing takeoff weight. A better design approach also takes into account factors such as aircraft demand, market uncertainty, and development and manufacturing costs. This paper presents a design methodology that integrates an aircraft performance model with a program valuation technique based on real options theory to address uncertain market demand and managerial flexibility. The coupled performance/financial framework enables an integrated approach to technical design and programmatic decisions. In addition, the methodology provides a framework for specification of design requirements and for quantification of the financial implications associated with technical and business uncertainty. The methodology is demonstrated for an aircraft design example of the blended-wing-body concept. Comparing performance-optimized and value-optimized designs, we show that use of value as a design metric leads to a trade-off between aerodynamic efficiency and reduced manufacturing costs. Key findings demonstrate that traditional financial metrics cause the decision maker to focus overly on reducing costs in the short term. The stochastic methodology shows that a willingness to spend up-front money in the design process to ensure long-term profitability is a better strategy.

Value-based multidisciplinary optimization for commercial aircraft design and business risk assessment

The energy finite element method (EFEM) provides researchers with an efficient tool to analyze high-frequency vibrating solid structures with less calculation and clear distribution of the energy density. However, the corresponding applications in structure optimization mainly focus on modifying the size and material properties, and it leaves a scientific gap that the topology flexibility is not addressed enough in the optimization. Therefore, this work aims at establishing an explicit level-set based topology optimization framework for the energy finite element method. A series of basic technical aspects, including the explicit level set description method, customized finite element mesh, mathematical model, and sensitivity analysis, are presented. With these basic studies, an original EFEM-based topology optimization framework for thin-walled structures is established for the first time. It is a basic work to conduct topology optimization in terms of energy. Additional applications in curved surfaces, spatial structures, and compound materials can also be developed only by modifying the description and EFEM module. Finally, the proposed optimization is applied to classic stiffened plates. Further analyses indicate that the proposed EFEM-based topology optimization can improve the dynamic performance of high-frequency vibrating structures by 20%–80%.

Micheal Johnson Selvaraj

Papers

Flutter Analysing Over an Aircraft Wing During Cruise Speed