Integrated health monitoring is beneficial but due to reliability, weight, size, wiring and other constraints, the incorporation of instrumentation onto aircraft propulsion systems is limited. Conventional wired sensing systems are not always feasible due to size, weight constraints, and issues associated with cable routing. This paper presents an integrated and self-powered wireless system for high temperature (above 125°C) environments powered by a thermoelectric generator for bearing condition monitoring. Thermoelectric generator with internal oil cooling chamber is proposed to achieve higher energy output for small temperature gradient recorded in the jet engine in comparison with other thermoelectric generators with heat sinks. The experimental results demonstrate that, under a simulated engine environment, the thermoelectric generator can provide sufficient energy for a wireless sensing system to collect environmental data every 46 s, and transmit every 260 s, during the critical take-off phase of flight and part of cruise.

Lithium-ion cells are increasingly being used as central power storage systems for modern applications, i.e., e-bikes, electric vehicles (EVs), satellites, and spacecraft, and they face significant and constant vibrations. This review examines how these vibrations affect the batteries’ mechanical, thermal, and electrical properties. Vibrations can cause structural issues, such as the separation of electrodes and the deformation of separators. These problems raise internal resistance and lead to localized heat generation. As a result, thermal management becomes more complicated, battery aging accelerates, and safety risks arise, including short circuits and thermal runaways. To tackle these challenges, we need more realistic testing protocols that consider the combined effects of vibrations, temperature, and mechanical stress. Improving thermal management systems (TMSs) using advanced cooling techniques and materials, e.g., phase change solutions, can help to alleviate these problems. It is also essential to design batteries with vibration-resistant materials and enhanced structural integrity to boost their durability. Moreover, vibrations play a significant role in various degradation mechanisms, including dendrite formation, self-discharge, and lithium plating, all of which can reduce battery capacity and lifespan. Our current research builds on these insights using a multiscale physics-based modeling approach to investigate how vibrations interact with thermal behavior and contribute to battery degradation. By combining computational models with experimental data, we aim to develop strategies and tools to enhance lithium-ion batteries’ safety, reliability, and longevity in challenging environments.

Low-cost airlines have significantly increased air transport, thus an increase in aviation noise. Therefore, predicting aircraft noise is an important component for designing an aircraft to reduce its impact on environmental noise along with the cost of testing and certification. The aim of this work is to develop a three-dimensional Boundary Element Method (BEM), which can predict the sound propagation and scattering over metamaterials and metasurfaces in mean flow. A methodology for the implementation of metamaterials and metasurfaces in BEM as an impedance patch is presented here. A three-dimensional BEM named as BEM3D has been developed to solve the aero-acoustics problems, which incorporates the Fast Multipole Method to solve large scale acoustics problems, Taylor’s transformation to account for uniform and non-uniform mean flow, impedance and non-local boundary conditions for the implementation of metamaterials. To validate BEM3D, the predictions have been benchmarked against the Finite Element Method (FEM) simulations and experimental data. It has been concluded that for no flow case BEM3D gives identical acoustics potential values against benchmarked FEM (COMSOL) predictions. For Mach number of 0.1, the BEM3D and FEM (COMSOL) predictions show small differences. The difference between BEM3D and FEM (COMSOL) predictions increases further for higher Mach number of 0.2 and 0.3. The increase in difference with Mach number is because Taylor’s Transformation gives an approximate solution for the boundary integral equation. Nevertheless, it has been concluded that Taylor’s transformation gives reasonable predictions for low Mach number of up to 0.3. BEM3D predictions have been validated against experimental data on a flat plate and a duct. Very good agreement has been found between the measured data and BEM3D predictions for sound propagation without and with the mean flow at low Mach number.

It's essential to maintain a consistent and dependable energy supplies given the rising global demand for energy. When there is a crisis, such as a malfunction or an imbalance between energy production and load demand, the Frequency system becomes unstable. A load shedding scheme is an important key to recover frequency system and ensure the obtainability of electrical power for serious loads in a plant. Therefore, it is necessary to provide reliable technologies to quickly and accurately way to prevent breakdown in the system energy. Under Frequency Load SheddingUFLS is one of the important systems protection, and as is currently the case in many instances, it is the final step to prevent the system's collapse following an interruption or failure energy in the system. In this paper, the review of the literature is presented, along with a look at the various methods employed in the electrical power system and a comparison of traditional, adaptive, and intelligent load-shedding strategies. In order to clarify the intended function (entity) and preserve system stability, extra classification of additional elements is suggested. The various load shedding systems were addressed, along with their benefits and drawbacks, and a comparison between them was made with a list of the most significant justifications for doing so.

It's essential to maintain a consistent and dependable energy supplies given the rising global demand for energy. When there is a crisis, such as a malfunction or an imbalance between energy production and load demand, the Frequency system becomes unstable. A load shedding scheme is an important key to recover frequency system and ensure the obtainability of electrical power for serious loads in a plant. Therefore, it is necessary to provide reliable technologies to quickly and accurately way to prevent breakdown in the system energy. Under Frequency Load SheddingUFLS is one of the important systems protection, and as is currently the case in many instances, it is the final step to prevent the system's collapse following an interruption or failure energy in the system. In this paper, the review of the literature is presented, along with a look at the various methods employed in the electrical power system and a comparison of traditional, adaptive, and intelligent load-shedding strategies. In order to clarify the intended function (entity) and preserve system stability, extra classification of additional elements is suggested. The various load shedding systems were addressed, along with their benefits and drawbacks, and a comparison between them was made with a list of the most significant justifications for doing so.