Search Results (171)

Decarbonizing heavy-duty transport in the mining sector requires a deep understanding of the interplay between specific energy consumption, payload dynamics, and ambient thermal stressors. This study presents an integrated, physics-informed machine learning framework to compare the energy intensity of battery-electric (EV) and diesel internal combustion engine (ICE) tippers on a real quarry route in Poland. We develop a bidirectional, route-aware model using physical force balance and high-resolution elevation data to estimate net energy consumption and regenerative braking potential over a complete closed-loop cycle. Furthermore, an Artificial Intelligence analysis utilizing a Random Forest regressor is implemented to simulate and quantify the non-linear impacts of ambient temperature, haul road rolling resistance, and payload mass on the specific energy intensity ($E_{spec}$). Results indicate that while EV energy demand surges in sub-zero climates due to parasitic battery thermal management loads, electric powertrains exhibit a profound thermodynamic advantage during loaded downhill segments, acting as net energy generators via recuperation. The proposed multi-factor approach provides a robust predictive tool for optimizing fleet deployment, infrastructure positioning, and decarbonization pathways in transitionary mining environments. Full article

The rapid expansion of Unmanned Aerial Vehicle (UAV) applications in both civilian and military sectors has intensified the demand for propulsion systems capable of delivering higher speed, increased endurance, and improved payload capacity. While battery-electric propulsion remains dominant for small UAV platforms, its limited energy density restricts operational range and mission flexibility. As a result, micro gas engines have emerged as a viable alternative for applications requiring high power-to-weight ratios and sustained high-speed operation. This review examines the fundamentals, scaling effects, and classification of micro gas turbine propulsion systems used in UAV applications, with emphasis on micro turbojets and related hybrid configurations. The paper discusses the thermodynamic principles governing micro gas engines and analyzes the aerodynamic, thermal, and combustion challenges associated with miniaturization, including low Reynolds number effects, tip leakage losses, thermal management limitations, and combustion instability. Furthermore, the study reviews the operational characteristics and mission suitability of different propulsion architectures for reconnaissance UAVs, high-speed UAVs, including reconnaissance and loitering platforms, target drones, and hybrid-electric aerial platforms. Recent developments involving additive manufacturing, advanced control systems, recuperated cycles, and hybrid-electric integration are also evaluated as enabling technologies for next-generation UAV propulsion. The findings demonstrate that although micro gas turbines continue to face important efficiency and manufacturing challenges at reduced scales, they remain essential for mission profiles that exceed the capabilities of purely electric propulsion systems. Full article

Under the background of the green transformation and energy conservation in the aviation field, hydrogen-fueled aero-engines are the primary direction for achieving sustainable aviation power development. However, the unique thermophysical properties of hydrogen fuel induce extreme thermal load challenges to engine thermal management. Based on the requirements of energy conservation and digital-intelligent technologies, this paper reviewed the recent research progress, important challenges, and future development directions in the thermal management field for hydrogen-fueled aero-engines, and filled the gaps in existing related reviews. (1) As for the liquid hydrogen thermal properties and thermal management requirements, the unique thermal physical properties of liquid hydrogen can easily cause fluctuations in heat load, large temperature differences, and material compatibility issues such as hydrogen embrittlement during storage, transportation, and combustion. The application of thermal barrier coatings, the design of targeted cooling structures, and the regulation of heat loss in the pipeline of the hydrogen supply system require particular attention. (2) As for the technical architecture and optimization of thermal management, the optimization of the high-pressure side manifolds in the cooled cooling air heat exchanger increases the flow uniformity by 18.8% and reduces the weight by 22.5%. The intercooled recuperated engine with the optimum area ratio reduces specific fuel consumption by 5.3% compared to the baseline engine in cruise. However, the system-level optimization research of the above widely recognized solutions is relatively limited in terms of coordinating the energy flow of engines. The baseline engine employed the method of system integration optimization to achieve a 2.99% increase in thrust and a 6.78% reduction in fuel consumption. (3) As for the thermal management modeling and simulation, the intelligent optimization method based on computational fluid dynamics reduces the pressure loss coefficient of the vane-integrated heat exchanger by 36%. Nevertheless, the multiphysics coupling model confronts a contradiction between computational cost and accuracy. (4) As for the comprehensive evaluation method, the advanced configuration of the hydrogen-fueled aero-engine can approximately reduce specific fuel consumption by 68.5% and NOx emission by 12.7% under the same maximum thrust condition. The hydrogen consumption of the proton exchange membrane fuel cells system model compared with the baseline system, optimized by the multi-objective optimization algorithm, has decreased by 15%, while the thermal uniformity has improved by 20–30%. However, the current evaluation system mostly focuses on a single dimension, lacking the analysis of nonlinear coupling among multiple factors and a closed-loop mechanism for evaluation, optimization, and verification. Future research should focus on the matching model of liquid hydrogen’s thermophysical properties and full flight conditions, global multi-energy flows optimization methods, multidimensional collaborative numerical simulation, multiphysics coupling models, and multidimensional comprehensive evaluation systems, to provide closed-loop theoretical support for the efficient, intelligent, and reliable thermal management system for hydrogen-fueled aero-engines. Full article

Decarbonizing industrial energy consumption is critical for global sustainability. This study evaluates renewable energy alternatives to replace fossil-fuel power generation at an oil and gas facility in Khurais, KSA. A comparative thermodynamic and economic assessment was performed between a photovoltaic (PV) array and a parabolic trough collector (PTC) integrated with a Brayton cycle (BC) and a bottoming organic Rankine cycle (RC). The PTC-BC-RC model includes multi-generation capabilities for electricity, process hot water, and hydrogen via a PEM electrolyzer. The baseline PTC-BC-RC system generates up to 118.1 MW with a maximum thermal efficiency of 36.57%. The PEM electrolyzer utilizes 2% of the generated power to produce hydrogen at 0.0152 kg/s. Economically, the recuperated CSP system offsets its higher initial capital costs through diverse revenue streams (power, heat, and hydrogen), achieving a payback period of 5.13 years, significantly outperforming the PV system’s 6.80 years. Both configurations mitigate annual emissions by 747,000 tons of CO₂, 103.4 tons of NO_x, and 3.72 tons of SO₂. Despite regional limitations such as dust and water scarcity, the multi-generation PTC-BC-RC system proves economically and thermodynamically superior to the standalone PV system, offering a highly effective decarbonization strategy for industrial facilities in arid, high-irradiance zones. Full article

In battery electric vehicles (BEVs), range-extended electric vehicles (REEVs) are gaining prominence due to range limitations, long charging times, and limited charging infrastructure. Range losses are particularly evident under extreme climate conditions, necessitating the development of efficient range-extender (RE) systems. In this study, a liquefied petroleum gas (LPG)-fueled, recuperator-equipped Micro Gas Turbine (MGT) was modeled as a standalone range-extending power unit using the Simcenter simulation environment, and its thermodynamic performance was examined under extreme climate conditions. While existing MGT studies in the literature generally focus on diesel-fueled systems, this study fills a significant gap in the literature by modeling the effects of using low-carbon, high-energy-density LPG. The performance of the MGT system was analyzed in extreme cold (−10 °C), standard (20 °C), and hot (45 °C) climates; at three different turbine inlet temperatures (1000, 1100, and 1250 K); and at three recuperator effectiveness settings (0.75, 0.85, and 0.95). The developed MGT system achieved a maximum thermal efficiency of 41.1% and a specific fuel consumption (SFC) of 188.67 g/kWh under cold climate conditions of −10 °C (263.15 K), a turbine inlet temperature (TIT) of 1250 K, and a recuperator effectiveness of 0.95. Consequently, specific CO₂ emissions were reduced to 566.01 g/kWh. The study’s most significant contribution to the literature is that the developed system offers high thermal efficiency, low fuel consumption, and low emissions under extremely cold climate conditions (−10 °C), where electric vehicle batteries typically experience performance and range loss. The LPG-fueled micro gas turbine with a recuperator demonstrates the potential to serve as an efficient, low-emission and competitive auxiliary power unit (APU) for range-extender applications, particularly under extreme climatic conditions. Full article

Distributed electric propulsion (DEP) systems offer a wide range of options for arranging the propulsion units on an aircraft. In most cases, the position of the propulsion systems is optimized for one specific flight phase, e.g., takeoff or cruise. Taking advantage of the high lift potential of the DEP also during descent and approach phases represents a challenge due to increased thrust. Energy harvesting propellers (EHPs) can be used to adapt the resulting thrust, by generation an additional drag force while regenerating a certain amount of energy back into the system. Therefore, the scaled flight demonstrator (SFD) e-Genius-Mod was modified to implement an energy harvesting powertrain in a DEP system. The energy harvesting wingtip propellers are integrated in a pusher configuration. It is possible to investigate different operation modes for recuperation, such as Windmilling and Opposite Pitch, by adjusting different propeller pitch angles. The electronics used for the wingtip propellers (WTPs) enable the control and measurement of the recuperation performance and furthermore to charge recuperated energy back into the battery. The energy harvesting system was tested in a wind tunnel to verify its functionality. In Windmilling mode, the maximum mean electrical power output is −25.7 W. In Opposite Pitch mode, the values were significantly higher, with a maximum mean electrical power of −184 W. This corresponds to up to seven times as much regenerated power in Opposite Pitch mode. Full article

As aviation faces growing pressure to reduce its climate impact, the exFAN project investigates a hydrogen fuel cell aircraft concept equipped with a heat recuperation system that reuses waste thermal energy to improve efficiency and lower fuel demand. This study compares the exFAN configuration with five major propulsion pathways, kerosene, bio-fuel, e-fuel, hydrogen combustion, and standard fuel cell systems, through an integrated well-to-wake (WTT + TTW) assessment including both CO₂ and non-CO₂ effects. The exFAN results are preliminary and based on analytical estimations regarding potential efficiency gains and fuel savings, providing an indicative view of hydrogen aviation’s lowest achievable climate footprint. Full article

In an era of rising geopolitical tensions, repeated global crises, and growing uncertainty in trade and finance, economic resilience has become a key priority for policymakers. This study presents an understanding by distinguishing regional resilience from global resilience, offering hardnosed explanations of both concepts and outlining mensurable indicators for each. Regional resilience is the capacity of an economy to endure and recuperate from shocks by way of strong, cost-effective connections in its region. These could be seen in terms of intra-bloc trade power, trade concentration, intra-regional investment flows and constant capital flows, which indicate the deep economical integration and interdependence. On the contrary, global resilience is concerned with the extent to which an economy is guarded by larger global diversification. It is quantified by the distribution of exports and investments geographically, the extent and diversity of trade partners, membership on global value chains, and the stability of the cross-border capital flows. Understanding the difference between these two forms of resilience has become increasingly important for policy design, especially in a period marked by repeated crises, geopolitical tension, and shifting trade and financial conditions. Countries must decide not only how open their economies should be, but also whether openness should be integrated regionally, diversified globally, or stable through a hybrid approach. Further, it argues that regional integration is peculiarly invaluable during region-wide disruptions such as pandemics, financial crises, or supply shortages, where integrated policies can reduce adjustment costs and protect demand and supply chains. However, global diversification becomes significant in areas such as energy and commodity security, where dependence on limited suppliers can magnify risks. Ultimately, most economies benefit from combining both approaches (a hybrid approach), adapting their strategy to the development stage, institutional strengths, and exposure to external shocks. Full article

This study examines how longitudinal road gradients affect the energy consumption and driving range of a Tesla electric vehicle using dynamometer measurements and Simulink simulations. Tests performed on slopes from 0% to 4% show a strong inverse relationship between gradient and range, with more than a 62% reduction at a 4% incline. The Simulink model accurately reproduces these trends despite the tested vehicle’s age and battery degradation. Shifting from driving range to energy consumption metrics provides a more robust assessment of vehicle efficiency, revealing that uphill segments substantially increase consumption, while downhill segments enable significant recuperation. When averaged, these effects nearly cancel out for moderate slopes, especially at higher speeds where aerodynamic drag dominates. Constant-speed simulations confirm that slope has minimal net impact at highway speeds but strongly affects consumption at urban speeds, with increases of up to 17% at a 4% gradient. Overall, the findings highlight road gradients as a key factor in EV energy modelling and emphasize the need to incorporate terrain and driving environment into predictive range estimation and eco-routing strategies. Full article

Despite extensive research into regenerative braking technology, balancing braking safety and energy recovery efficiency remains a challenge under complex and varied driving conditions. To address this, this paper proposes an adaptive fuzzy control strategy for the regenerative braking system in dual-drive electric motorcycles. Using braking intensity, vehicle speed, and battery state of charge (SOC) as inputs, the strategy employs fuzzy reasoning to dynamically adjust the regenerative braking force ratio in real-time. This approach maximizes energy recovery efficiency while ensuring braking safety. A co-simulation platform for the electromechanical hybrid braking system of the entire vehicle was built using MATLAB/Simulink and BikeSim. Compared with the conventional constant-regeneration scheme, the proposed adaptive fuzzy control strategy achieves a remarkable improvement in energy recuperation efficiency—25.97% under WMTC and 26.43% under FTP-75, respectively—while simultaneously increasing the terminal battery SOC by 2.1% and 1.3%. These quantitative gains substantiate the superior capability of the strategy to dynamically reconcile braking stability with energy-harvesting objectives across diverse driving conditions. By fully exploiting the regenerative potential of dual-drive architectures, the proposed control approach not only extends the achievable driving range but also provides a scalable framework for high-efficiency regenerative braking control in future lightweight electric vehicles. Full article

The utilization of thermoelectric systems within internal combustion engines has emerged as a promising approach to recuperate a portion of the energy dissipated through exhaust gases. The objective of this study is twofold: firstly, to assess the heat recovery potential of a thermoelectric generator integrated into a diesel engine, and secondly, to elucidate the impact of varying operating conditions on the efficiency of heat recovery. For this purpose, the thermoelectric generator was mounted onto the exhaust pipe of a single-cylinder diesel engine featuring a common-rail fuel injection system with pilot injection and a displacement volume of 1.12 L. The calculations were conducted under 100% engine load at 1500 RPM engine speed and three different injection timing settings (−2, STD, and +2 °CA). The optimum heat recovery efficiency was determined to be 5.02%, which was achieved under the following conditions: B50 fuel, −2 °CA injection timing, 1500 RPM engine speed, and 100% engine load. Full article

Supercritical carbon dioxide (SC-CO₂) power cycles offer a promising solution for offshore platforms’ gas turbine waste heat recovery due to their compact design and high thermal efficiency. This study proposes a novel parallel-preheating recuperated Brayton cycle (PBC) using SC-CO₂ for waste heat recovery on offshore gas turbines. An integrated energy, exergy, and economic (3E) model was developed and showed good predictive accuracy (deviations < 3%). The comparative analysis indicates that the PBC significantly outperforms the simple recuperated Brayton cycle (SBC). Under 100% load conditions, the PBC achieves a net power output of 4.55 MW, while the SBC reaches 3.28 MW, representing a power output increase of approximately 27.9%. In terms of thermal efficiency, the PBC reaches 36.7%, compared to 21.5% for the SBC, marking an improvement of about 41.4%. Additionally, the electricity generation cost of the PBC is 0.391 CNY/kWh, whereas that of the SBC is 0.43 CNY/kWh, corresponding to a cost reduction of approximately 21.23%. Even at 30% gas turbine load, the PBC maintains high thermoelectric and exergy efficiencies of 30.54% and 35.43%, respectively, despite a 50.8% reduction in net power from full load. The results demonstrate that the integrated preheater effectively recovers residual flue gas heat, enhancing overall performance. To meet the spatial constraints of offshore platforms, we maintained a pinch-point temperature difference of approximately 20 K in both the preheater and heater by adjusting the flow split ratio. This approach ensures a compact system layout while balancing cycle thermal efficiency with economic viability. This study offers valuable insights into the PBC’s variable-load performance and provides theoretical guidance for its practical optimization in engineering applications. Full article

The article examines the problems associated with the use of waste thermal energy. A new concept is developed on how to improve an atmospheric condensing engine by using low-temperature waste thermal energy, converting it into energy acceptable to the consumer (mechanical, electrical energy). The article presents a new scheme of a staged atmospheric condensing engine, thanks to which (based on preliminary calculations and recuperator verification experiments) it is possible to increase the efficiency of the condensing engine from 6.3% to 17%. At low temperatures (80–150 °C) this is a very high efficiency, since devices operating at low temperatures, for example, devices operating on the Rankine cycle, only have an efficiency of about 4.2–9%. Full article

With the growing deployment of electric buses (e-buses), accurate energy use modelling has become essential for fleet optimisation and operational planning. Using the SORT methodology, this study analyses instantaneous energy consumption and recuperation (IECR). Three vehicle configurations were tested (one battery with pantograph, four batteries, and eight batteries), each with ten repeatable runs. Four approaches were compared: a baseline linear regression, an extended linear model (ELM) due to the state, a feed-forward neural network, and a recurrent neural network (RNN). The extended linear model achieved a determination coefficient of R² = 0.9124 (residual standard deviation 4.26) compared with R² = 0.7859 for the baseline, while the determination coefficient for the RNN is 0.9343, and the RNN provided the highest accuracy on the test set (the correlation coefficient between real and predicted values is 0.9666). The results confirm the dominant influence of speed and acceleration on IECR and show that battery configuration mainly affects consumption during acceleration. Literature-consistent findings indicate that regenerative systems can recover 25–51% of braking energy, with advanced control methods further improving recovery. Despite non-normality and temporal dependence of residuals, the state-aware linear model remains interpretable and competitive, whereas recurrent networks offer superior fidelity. These results support real-time energy management, charging optimisation, and reliable range prediction for electric buses in urban public transport. Full article

This article describes the implemented technological solution of utilizing waste heat by upgrading the potato protein drying line and using energy recuperation in the drying plant. In this article, the technological sequence of the potato starch and potato protein production plant was analyzed and the identification of possible solutions that lead to a reduction in energy demand was described. The method of analyzing the processing data is based on existing models describing the flow of mass and energy fluxes. The authors did not seek new mathematical descriptions of the physicochemical phenomena occurring during the drying processes, and only modification of the technological line based on the current state of knowledge in process engineering has been proposed. The full heat recovery of the production line was applied, and the exhaust air after drying and the heat from the decanter leachate after centrifugation of the coagulated potato protein, from two energy-coupled starch dryers, were used as the source of recovered heat energy. Temperature measurements were taken at key process nodes, and the energy effects were estimated after the process line upgrade. The solution proposed in the article fits with circular economy, bringing notable economic and environmental benefits consisting of utilizing waste heat from technological processes in the food industry. Full article