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Projects related to green aviation designed to achieve fuel savings and emission reductions are increasingly being established in response to growing concerns over climate change. Within the aviation industry, there is a growing trend towards the electrification of aircraft, with more-electric aircraft (MEA) and all-electric aircraft (AEA) being proposed. However, increasing electrification causes challenges with conventional thermal management system (TMS) and power management system (PMS) designs in aircraft. As a result, the integrated power and thermal management system (IPTMS) has been developed for energy-optimised aircraft projects. This review paper aims to review recent IPTMS progress and explore potential design solutions for civil aircraft. Firstly, the paper reviews the IPTMS in electrified propulsion aircraft (EPA), presenting the architectures and challenges of the propulsion systems, the TMS cooling strategies, and the power management optimisation. Then, several research topics in IPTMS are reviewed in detail: architecture design, power management optimisation, modelling, and analysis method development. Through the review of state-of-the-art IPTMS research, the challenges and future opportunities and requirements of IPTMS design are discussed. Based on the discussions, two potential solutions for IPTMS to address the challenges of civil EPA are proposed, including the combination of architecture design and power management optimisation and the combination of modelling and analysis methods.

In this work, polyvinyl pyrrolidone (PVP) non-covalently functionalized multi-walled carbon nanotubes (MWCNTs), graphene nanoplates (GNPs) and MWCNTs/GNPs hybrids were respectively dispersed into epoxy adhesive to investigate their effects on mode I fracture toughness of unidirectional composite bonded joints through double cantilever beam tests. The synergy effects of MWCNTs and GNPs with different ratios were also studied. Testing results showed that 0.75 wt% MWCNTs/GNPs (1:4) hybrid had the highest toughening effect of 286% improvement compared with pure adhesive. In addition, PVP was proved to have a positive effect on improving fracture toughness for single nanofillers while it declined the toughening effect of MWCNTs/GNPs hybrids. Furthermore, the fracture micromorphology of adhesive layer as well as the toughening mechanisms of MWCNTs, GNPs and MWCNTs/GNPs hybrids were analyzed.

Heat-pipe-cooled microreactors (HPMR) use a passive high-temperature alkali metal heat pipe to directly transfer the heat of solid core to the hot end of the intermediate heat exchanger or thermoelectric conversion device, thus avoiding a single point failure. To analyze and evaluate the transient safety characteristics of an HPMR system under accident conditions, such as heat pipe failure in the core or a loss of system heat sink and other accidents, a previously developed model for transient analysis of a heat-pipe-cooled space nuclear reactor power system (HPSR) was improved and validated in this study. The models improved mainly comprise: (1) An entire 2-D solid-core heat transfer model is established to analyze the accident conditions of core heat pipe failure and system heat sink loss. In this model, radial and axial Fourier heat conduction equations are used to divide the core into r-θ direction control volumes. The physical parameters of the material in the control volume are calculated according to the volume-weighted average. (2) By coupling the heat transfer limit model and the two-dimensional thermal resistance network model, the transient model of a heat pipe for HPMR system analysis is improved. (3) Conversion system models are established to simulate the system characteristics of the advanced HPMR concept, such as thermoelectric conversion, Stirling conversion, and the open Brayton conversion analysis model. Based on the improved models, the HPMR system analysis program TAPIRSD was developed, which was verified by experimental data of the separated conversion components and the ground nuclear test device KRUSTY. The maximum deviation of the power output predicted by the energy conversion model is less than 8%. The accident conditions of the KRUSTY tests, such as load change, core heat pipe failure, and heat sink loss accident, were studied by using TAPIRSD. The results show that the simulation results of the TAPIRSD code agree well with the experimental data of the KRUSTY prototype reactor. The maximum error between the TAPIRSD code prediction and the measured value of the core temperature under accident conditions is less than 10 K, and the maximum deviation is less than 2%. The results show that the developed code can predict the transient response process of the HPMR system well. At the same time, the accuracy and reliability of the improved model are proved. The TAPIRSD is suitable for system transient analysis of different types of HPMRs and provides an optional tool for the system safety characteristics analysis of HPMR.

Aircraft electrification introduces challenges in power and thermal management. In a hybrid-electric aircraft (HEA), the additional heat loads generated by the high-power electrical components in the propulsion system can negate the benefits of the HEA. Consequently, an integrated energy management system is required for the HEA to reject the additional heat loads while minimizing energy consumption. This paper presents the integrated modeling method for an integrated power and thermal management system (IPTMS) for HEA. With this method, a platform can be developed to assess the varying efficiencies of the components in the electrical propulsion system (EPS), such as the battery, motor, bus, and converter, and the performance of the thermal management system (TMS), such as passive cooling, during a flight mission. This makes it applicable to modular designs and optimizations of the IPTMS. A small/medium range (SMR) aircraft similar to ATR72 is studied to demonstrate the platform's capabilities. In this study, the EPS operates only during takeoff and climb. It provides supplementary propulsive power, which declines linearly from 924 kW to zero. Therefore, the platform assesses the heat and power loads of the IPTMS for a typical flight mission (takeoff and climb) in this study. The performance of passive cooling is also analyzed across this typical flight mission and under normal, hot-day, and cold-day conditions. It was found that under the normal condition, after the midclimb flight mission, the EPS components except for the motor and the inverter can be cooled sufficiently by the passive cooling mechanism without any need for active cooling. However, the battery temperature decreases below its minimum operating temperature (15 °C) after the late-climb segment indicating the need for active temperature control to prevent damage. The passive cooling is still sufficient under the hot-day and cold-day conditions. Additionally, compared with the normal condition, the points at which passive cooling is sufficient to cool the component move forward in the hot-day condition and backward in the cold-day condition, respectively. Under the hot-day condition, the battery temperature is below its minimum temperature after the late-climb, still requiring active temperature control. In the cold-day condition, the bus, the converter, and the battery require active temperature control to prevent their temperatures below the minimum temperatures. Additionally, the heat from the gas turbine (GT) engine has a positive impact to ensure the motor and the inverter operate at their operating temperatures in cold conditions. The studied aircraft can be assessed with the integrated model under normal, hot-day, and cold-day conditions for heat and power loads, as well as passive TMS performance. This demonstrates the adaptability of the integrated modeling method. These findings imply the potential to minimize TMS weight and energy consumption, providing an insight for further research on IPTMS. [ABSTRACT FROM AUTHOR]