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With the continuous growth in the volume of global air transportation, the carbon emissions of the civil aviation industry have received increasing attention. Carbon emission reduction in civil aviation is an inevitable requirement for achieving sustainable social development. This article aims to use system dynamics (SD) methods to establish a carbon emission model for the civil aviation industry that includes economic, demographic, technological, policy, and behavioral factors; analyze the key factors that affect carbon emissions; and explore effective emission reduction strategies. Researchers have found that SD-based carbon emission prediction has a high accuracy and is suitable for predicting carbon emissions in civil aviation. Through different scenario simulations, it has been found that any single emission reduction measure will struggle to effectively contribute to the expected carbon reductions in China's civil aviation. Simultaneously adopting measures such as improving fuel efficiency, adopting clean energy, and using new-power aircraft is an effective way to reduce carbon emissions from civil aviation. In addition, policy intervention and technological innovation are equally crucial for achieving long-term emission reduction goals. The research results not only provide a scientific basis for the sustainable development of the aviation industry but also provide a reference for policymakers to formulate comprehensive emission reduction strategies. [ABSTRACT FROM AUTHOR]

The increasing deployment of CubeSats in space missions necessitates the development of efficient and reliable orbital maneuvering techniques, particularly given the constraints on fuel capacity and computational resources. This paper presents a novel two-level control architecture designed to enhance the accuracy and robustness of CubeSat orbital maneuvers. The proposed method integrates a J2-optimized sequence at the high level to leverage natural perturbative effects for fuel-efficient orbit corrections, with a gated recurrent unit (GRU)-based low-level controller that dynamically adjusts the maneuver sequence in real-time to account for unmodeled dynamics and external disturbances. A Kalman filter is employed to estimate the pointing accuracy, which represents the uncertainties in the thrust direction, enabling the GRU to compensate for these uncertainties and ensure precise maneuver execution. This integrated approach significantly enhances both the positional accuracy and fuel efficiency of CubeSat maneuvers. Unlike traditional methods, which either rely on extensive pre-mission planning or computationally expensive control algorithms, our architecture efficiently balances fuel consumption with real-time adaptability, making it well-suited for the resource constraints of CubeSat platforms. The effectiveness of the proposed approach is evaluated through a series of simulations, including an orbit correction scenario and a Monte Carlo analysis. The results demonstrate that the integrated J2-GRU system significantly improves positional accuracy and reduces fuel consumption compared to traditional methods. Even under conditions of high uncertainty, the GRU-based control layer effectively compensates for errors in thrust direction, maintaining a low miss distance throughout the maneuvering period. Additionally, the GRU's simpler architecture provides computational advantages over more complex models such as long short-term memory (LSTM) networks, making it more suitable for onboard CubeSat implementations. [ABSTRACT FROM AUTHOR]

Agricultural tractors are an essential agricultural power source. Therefore, the scientific literature tests have described agricultural tractors' evolution over time and determined future trends. This paper uses bibliometric tools to assess the agricultural evolution of tractor testing from 1969 to 2022 to ascertain the publication's scientific perspective on operational, ergonomic, and energy performance. We searched for relevant research in the Scopus and Web of Science (WOS) databases. The data were processed in RStudio software version 4.4.1, and we used elaborated bibliometric maps to research evolution, major journals, studies, countries, and keywords. The first research mainly concerned the development of new wheelsets, more efficient engines, and fuel consumption prediction models. After the 2000s, environmental protocols contributed to increasing publications on biofuels and renewable energies. Recently, an intense process of robotization in autonomous vehicles has improved to allow the replacement of combustion engines. Ergonomics and safety have been less recurrent topics in recent years, indicating a stable level in the actual research. New machine control models involving artificial intelligence are currently applied to obtain test results without using the machine in the field. These virtual models reduce costs and optimize resources. The most common terms were "tractor" and "agricultural machinery". The terms "Electric tractor", "agricultural robots", and "Matlab" indicate solid trends for future research. [ABSTRACT FROM AUTHOR]

The dynamic behaviour of a spring-mounted symmetrical NACA0012 wing in a freestream flow of air is studied in the pre-stall region, over 0° to 12° angles of incidence. The primary aim of this work is for use within the automotive sector to reduce drag and fuel emissions. However, this work will also be of interest in the motorsport sector to improve performance, and also have some applications within the aerospace and renewable energy sectors. The general operation of the concept has previously been verified at these low angles in the pre-stall region with that of a theoretical estimation using finite and infinite wings. This paper provides a numerical solution of the same problem and is compared with the previous experimentation. At these low angles, the computations yield a dynamic response settling into a static equilibrium. The stable solutions match the start of a steady regime well, when compared with the experiment. The trends are also comparable with the experiment, but the velocities at which they occur are underestimated in the computation. The computations demonstrate a drag reduction of 59% when compared to a fixed wing, whereas the lift remains stable at a near constant value with increasing wind speed. Thence, downforce is maintained whilst drag is reduced, which will facilitate higher speeds on the straight whilst maintaining vehicle direction stability. Limitations to this proof-of-concept work are highlighted and future development work is suggested to achieve even further increases in performance. [ABSTRACT FROM AUTHOR]

The dynamic behaviour of a spring-mounted symmetrical NACA0012 wing in a freestream flow of air is studied in the pre-stall region, over 0° to 12° angles of incidence. The primary aim of this work is for use within the automotive sector to reduce drag and fuel emissions. However, this work will also be of interest in the motorsport sector to improve performance, and also have some applications within the aerospace and renewable energy sectors. The general operation of the concept has previously been verified at these low angles in the pre-stall region with that of a theoretical estimation using finite and infinite wings. This paper provides a numerical solution of the same problem and is compared with the previous experimentation. At these low angles, the computations yield a dynamic response settling into a static equilibrium. The stable solutions match the start of a steady regime well, when compared with the experiment. The trends are also comparable with the experiment, but the velocities at which they occur are underestimated in the computation. The computations demonstrate a drag reduction of 59% when compared to a fixed wing, whereas the lift remains stable at a near constant value with increasing wind speed. Thence, downforce is maintained whilst drag is reduced, which will facilitate higher speeds on the straight whilst maintaining vehicle direction stability. Limitations to this proof-of-concept work are highlighted and future development work is suggested to achieve even further increases in performance.

With the publication of this article, the authors continue the research on the development and testing of a methodology for in-flight aircraft rerouting which have begun in previously published articles in the Civil Aviation High Technologies of the Moscow State Technical University of Civil Aviation. This article presents the results of the study in terms of developing the potentials of the methodology from reconfiguring a route of a hypothetical aircraft and obstacles in the horizontal plane, which were previously demonstrated, prior to rerouting in both the horizontal and vertical planes for two different types of obstacles: 1) ground natural or artificial (mountain, power line support, etc.); 2) air (squall line, prohibited flight area, etc.) and their combinations using an example of a Mi-8 helicopter flight on route using a real digital map of the terrain. As mentioned above, a large amount of aviation accidents is associated with the loss of control in-flight, as well as the collision with terrain in a controlled flight (categories LOC-I, CFIT, LALT). As a result of the investigation of the aviation accidents, it was found that these accidents are often caused by the requirement to reroute quickly due to obstacles, for example, a squall line. When determining alternatives to avoid an obstacle, as well as while implementing the selected route for avoiding action, the crew makes errors due to the increased psychophysiological load and lack of time. The methodology and the algorithms, proposed by the authors, make it possible to assess the safety of an original route, estimate options for alternatives to avoid around obstacles detected in-flight, check them for feasibility, taking into account aircraft performance, flight envelope, and also select the optimal route from the view of some criterion, for example, based on minimizing the route length increase, reducing additional fuel consumption, the time required to implement a new route of flight, etc.

Agricultural tractors are an essential agricultural power source. Therefore, the scientific literature tests have described agricultural tractors’ evolution over time and determined future trends. This paper uses bibliometric tools to assess the agricultural evolution of tractor testing from 1969 to 2022 to ascertain the publication’s scientific perspective on operational, ergonomic, and energy performance. We searched for relevant research in the Scopus and Web of Science (WOS) databases. The data were processed in RStudio software version 4.4.1, and we used elaborated bibliometric maps to research evolution, major journals, studies, countries, and keywords. The first research mainly concerned the development of new wheelsets, more efficient engines, and fuel consumption prediction models. After the 2000s, environmental protocols contributed to increasing publications on biofuels and renewable energies. Recently, an intense process of robotization in autonomous vehicles has improved to allow the replacement of combustion engines. Ergonomics and safety have been less recurrent topics in recent years, indicating a stable level in the actual research. New machine control models involving artificial intelligence are currently applied to obtain test results without using the machine in the field. These virtual models reduce costs and optimize resources. The most common terms were “tractor” and “agricultural machinery”. The terms “Electric tractor”, “agricultural robots”, and “Matlab” indicate solid trends for future research.

Purpose. The paper aims to investigate the increase of fuel efficiency of a mainline freight locomotive in the case of separate loading of diesel generators of its individual sections. Methodology. The study was carried out for the non-electrified section between Kharkiv-Sorting and Sumy stations during the movement of a freight train with 45 loaded and empty freight cars in both directions. The movement of a train with a freight mainline two-section diesel locomotive 2TE116 was taken. To determine the parameters of the movement, a mathematical model was developed, which was used to solve a series of traction problems. The traction problems are calculated for the cases of train movement with a series diesel locomotive and a diesel locomotive with separate loading of diesel generators of its individual sections. A method of loading sections is proposed for modeling and the traction characteristics of the locomotive are constructed in accordance with this method. Findings. It has been established that the use of separate loading of diesel generators of individual sections of a diesel locomotive when running a train with loaded cars reduces fuel consumption by 18.7...19.6 % compared to running a serial diesel locomotive. For the case of a train with empty cars, the reduction in fuel consumption is 8.1...10.3 % compared to a train with a serial diesel locomotive. It has been found that the movement of a train with empty cars can be carried out with traction by one section of a diesel locomotive. In this case, the reduction in fuel consumption is 29.5...31.0 %. In all the studied cases, the duration of the movement is practically the same. Originality. The authors of this paper have solved traction problems for a real track section when a train with a freight diesel locomotive is moving, where separate loading of diesel generators of its sections is used. A method for forming the traction characteristics of a locomotive with separate loading of diesel generators is proposed. Practical value. The developed mathematical models of train movement, including for the case of separate loading of diesel generators of diesel locomotive sections, can be used in the modernization of diesel locomotives or the creation of diesel rolling stock using a multi-diesel power plant.

Due to growing environmental concerns and stringent emissions regulations, optimizing the fuel consumption of marine propulsion systems is crucial. This work deals with the potential in an LNG ship propulsion system to reduce fuel consumption through controlled load distribution between engines in Dual-Fuel Diesel Electric (DFDE) plant. Based on cyclical data acquisition measured onboard and using an optimization model, this study evaluates different load distribution strategies between setups according to the optimization model results and automatic (equal) operation to determine their effectiveness in improving fuel efficiency. The analysis includes scenarios with different fuel types, including LNG, MDO and HFO, at different engine loads. The results indicate that load distribution adjustment based on the optimization model results significantly improves fuel efficiency compared to conventional methods of uniform load distribution controlled by power management systems in almost all load intervals. This research contributes to the maritime industry by demonstrating that strategic load management can achieve significant fuel savings and reduce environmental impact, which is in line with global sustainability goals. This work not only provides a framework for the implementation of more efficient energy management systems on LNG vessels, but also sets a benchmark for future innovations in maritime energy optimization as well as in the view of exhaust emission reduction. [ABSTRACT FROM AUTHOR]

One of the areas for increasing energy efficiency in the production of electrical and thermal energy is the use of cogeneration units (CGU), which is due to an increase in the share of useful heat output to heat supply systems. Large combined heat and power plants (CHPs), as a rule, use steam turbine units, which serve as sources of thermal energy for heating and hot water supply in cities with a high concentration of heat load. In small and medium-sized cities, the main sources of thermal energy are boiler houses. With the advent of modern gas piston and gas turbine units on the market, it is possible to predict the creation of mini-CHPs based on them. To increase their fuel efficiency, it is advisable to use seasonal thermal storage (TS) as part of the municipal energy infrastructure in order to reduce the volume of thermal emissions during the nonheating period. [ABSTRACT FROM AUTHOR]

To reduce the modeling burden for control of spark-ignition engines, reinforcement learning (RL) has been applied to solve the dilute combustion limit problem. Q-learning was used to identify an optimal control policy to adjust the fuel injection quantity in each combustion cycle. A physics-based model was used to determine the relevant states of the system used for training the control policy in a data-efficient manner. The cost function was chosen such that high cycle-to-cycle variability (CCV) at the dilute limit was minimized while maintaining stoichiometric combustion as much as possible. Experimental results demonstrated a reduction of CCV after the training period with slightly lean combustion, contributing to a net increase in fuel conversion efficiency of 1.33%. To ensure stoichiometric combustion for three-way catalyst compatibility, a second feedback loop based on an exhaust oxygen sensor was incorporated into the fuel quantity controller using a slow proportional-integral (PI) controller. The closed-loop experiments showed that both feedback loops can cooperate effectively, maintaining stoichiometric combustion while reducing combustion CCV and increasing fuel conversion efficiency by 1.09%. Finally, a modified cost function was proposed to ensure stoichiometric combustion with a single controller. In addition, the learning period was shortened by half to evaluate the RL algorithm performance on limited training time. Experimental results showed that the modified cost function could achieve the desired CCV targets, however, the learning time was reduced by half and the fuel conversion efficiency increased only by 0.30%. [ABSTRACT FROM AUTHOR]

This research investigates the utilization of a hybrid nanofiller comprising graphene oxide (GO) and amine‐modified nano silica in natural rubber matrix via the latex stage coagulation method. The resulting novel composite materials were characterized comprehensively for their static and dynamic mechanical properties. The hybrid nanofiller exhibited excellent dispersion within the rubber latex, facilitating the formation of a well‐interconnected network structure. The formed network resulted in remarkable improvements in tensile strength, elongation at break, and modulus of the composites. Dynamic mechanical analysis revealed that the hybrid filler (GO/nano‐silica hybrid (GO/NS)) could effectively reinforce the rubber matrix by constraining the mobility of rubber chains, leading to increased stiffness and mechanical strength. In fact, the confinement effect of the nanofillers has been carefully evaluated from dynamic mechanical spectroscopy. The increased glass transition temperature of the rubber nanocomposites specifies the restricted segmental mobility of the rubber chains. Moreover, the hybrid composites displayed significantly low rolling resistance, particularly GO/NS 2 (31% reduction), indicating their potential application as tire treads for fuel‐efficient and green tire manufacturing. The mechanical and rolling resistance properties achieved in these composites can be attributed to the efficient dispersion of the GO/nano‐silica hybrid(GO/NS) nanofiller and the resulting network formation within the rubber matrix. Findings emphasized the composites' viability as sustainable and eco‐friendly tire materials, potential for enhanced fuel efficiency, and reduced environmental footprint in tire manufacturing technology. Highlights: The hybrid nanofiller (GO/nano silica hybrid) exhibited excellent dispersion within the rubber latex, leading to the formation of a well‐interconnected network structure.The resulting network structure significantly improved the tensile strength, elongation at break, and modulus of the composite materials.Dynamic mechanical analysis demonstrated that the hybrid filler effectively reinforced the rubber matrix, increasing stiffness and mechanical strength by constraining the mobility of rubber chains.Our hybrid composites displayed a remarkable reduction in rolling resistance, particularly GO/NS2, with a 31% reduction, indicating their potential application as tire treads for fuel‐efficient and green tire manufacturing.The study emphasized the composites viability as sustainable and eco‐friendly tire materials, offering potential benefits for enhanced fuel efficiency and reduced environmental footprint in tire manufacturing technology. [ABSTRACT FROM AUTHOR]

Endurance fuel calculations are used to determine the required volume of fuel tanks; annual fuel calculations are used to estimate the fuel consumed during a year of ship operations, primarily to estimate the projected cost of fuel as part of the life cycle cost estimate. These calculations depend on the fuel rates (kg/h) for different electrical and propulsion system configurations. The fuel rates in turn depend on factors, such as equipment efficiency, prime mover-specific fuel consumption curves, electrical loads, ambient temperature, propulsion loads, and the manner in which the power and propulsion systems, are operated. This paper details how to perform endurance fuel and annual fuel calculations, provides guidance for modeling system components based on data typically provided in data sheets, and provides guidance on the manner in which the power and propulsion systems are operated. Four examples are provided to illustrate the methods using the Smart Ship System Design modeling and simulation tool along with supporting spreadsheets. [ABSTRACT FROM AUTHOR]

The partial or total replacement of carbon black by silica fillers is initiated through various techniques for environment-friendly, smart, and fuel-efficient NR composites for high-end dynamic applications like tyre tread. The smart properties such as low rolling resistance, better wet skid resistance, and abrasion resistance as well as noise reduction, create tyre tread compounds with superior performance. The endeavour to maximise the incorporation of eco-friendly ingredients like silica filler in rubber compound associates to produce a green tyre product indeed. The present review encompasses those approaches with a substantial contribution in the area along with critical insights in the respective efforts. Initially, the various types of commercially available silica fillers are discussed in brief, followed by the various approaches for surface modification in detail. Finally, the miscellaneous initiatives along with their achievements and drawbacks are included under five strategic verticals for better understanding along with vital remarks. [ABSTRACT FROM AUTHOR]

Fuel consumption optimization is a critical field of research within the automotive industry to meet consumer expectations and regulatory requirements. A reduction in fuel consumption can be achieved by reducing the energy consumed by the vehicle. Several subsystems contribute to the overall energy consumption of the vehicle, including the air conditioning (A/C) system. The loads within the A/C system are mainly contributed by the compressor, condenser fan, and underhood aerodynamic drag, which are the components targeted for overall vehicle energy use reduction in this paper. This paper explores a new avenue for A/C system control by considering the power consumption due to vehicle drag (regulated by the condenser fan and active grille shutters (AGS)) to reduce the energy consumption of the A/C system and improve the overall vehicle fuel economy. The control approach used in this paper is model predictive control (MPC). The controller is designed in Simulink, where the compressor clutch signal, condenser fan speed, and AGS open-fraction are inputs. The controller is connected to a high-fidelity vehicle model in Gamma Technologies (GT)-Suite (which is treated as the real physical vehicle) to form a software-in-the-loop simulation environment, where the controller sends actuator inputs to GT-Suite and the vehicle response is sent back to the controller in Simulink. Quadratic programming is used to solve the MPC optimization problem and determine the optimal input trajectory at each time step. The results indicate that using MPC to control the compressor clutch, condenser fan, and AGS can provide a 37.6% reduction in the overall A/C system energy consumption and a 32.7% reduction in the error for the air temperature reference tracking compared to the conventional baseline proportional integral derivative control present in the GT-Suite model. [ABSTRACT FROM AUTHOR]

Purpose. To propose a modern methodological approach to determine the energy efficiency of passenger transportation by city buses by establishing the relationship between fuel consumption and the number of stops on the route, as well as an environmental assessment of the introduction of an express mode of bus traffic in the conditions of a modern metropolis. Methodology. The fuel balance equation of the vehicle was used to build a model for researching the energy resource efficiency of buses in different driving modes. Determining the criteria and limitations that determine the effectiveness of the express mode of bus traffic was carried out by methods of system analysis. Information about the number of stops (where passenger exchange takes place) and additional dynamic loads which are related to the level of occupancy of the bus cabin were used as input data for modelling. These indicators were determined on the basis of a survey of passenger flows. The values of the angles of the laterallongitudinal slope of the road and the distances of the sections between the stops were determined with the help of the Internet resources Google Earth Pro and Google maps, respectively. The number of additional stops at traffic lights was calculated as a weighted average value according to the Bernoulli distribution. Elements of functional analysis were used to justify the introduction of the combined mode of movement in the considered example. The economic evaluation was carried out in accordance with the Directive of the European Parliament and the Council of the EU 2009/33/EU. Findings. In the conducted studies, an ecological and economic evaluation of the introduction of an express mode of bus traffic in the conditions of a modern metropolis was provided. The results of the conducted research made it possible to determine the dependence of the energy resource efficiency of bus operation in different driving modes. Increasing the energy efficiency of transportation is achieved through the introduction of more productive and less expensive modes of bus traffic on city routes. It has been proven that the most effective one is the combined mode using regular and express connections. Originality. The authors believe that one of the effective measures to reduce the environmental consequences of the operation of urban public automobile transport is to increase the energy efficiency of transportation. This conclusion is based on the fact that one of the main quantitative indicators of the operation of vehicles is fuel consumption, which directly affects the mass of pollutant emissions and depends on the bus driving mode. Practical value. The proposed methodological approach is a universal algorithm that is proposed to be used by interested parties to assess the possibilities of reducing the negative impact of transport on the environment. The use of the developed approach in practice allows transport departments of city halls and akimats of megacities together with specialists of transport companies (developers of public transport routes) to reduce emissions of pollutants into the atmospheric air, achieving a minimal negative impact on the environment [ABSTRACT FROM AUTHOR]

The last decade (2013–2023) was the most prolific period of organic Rankine cycle (ORC) research in history in terms of both publications and citations. This article provides a detailed review of the broad and voluminous collection of recent internal combustion engine (ICE) waste heat recovery (WHR) studies, serving as a necessary follow-on to the author's 2013 review. Research efforts have targeted diverse applications (e.g., vehicular, stationary, and building-based), and it spans the full gamut of engine sizes and fuels. Furthermore, cycle configurations extend far beyond basic ORC and regenerative ORC, particularly with supercritical, trilateral, and multi-loop ORCs. Significant attention has been garnered by fourth-generation refrigerants like HFOs (hydrofluoroolefins), HFEs (hydrofluoroethers), natural refrigerants, and zeotropic mixtures, as research has migrated away from the popular HFC-245fa (hydrofluorocarbon). Performance-wise, the period was marked by a growing recognition of the diminished performance of physical systems under dynamic source conditions, especially compared to steady-state simulations. Through advancements in system control, especially using improved model predictive controllers, dynamics-based losses have been significantly reduced. Regarding practically minded investigations, research efforts have ameliorated working fluid flammability risks, limited thermal degradation, and pursued cost savings. State-of-the-art system designs and operational targets have emerged through increasingly sophisticated optimization efforts, with some studies leveraging "big data" and artificial intelligence. Major programs like SuperTruck II have further established the ongoing challenges of simultaneously meeting cost, size, and performance goals; however, off-the-shelf organic Rankine cycle systems are available today for engine waste heat recovery, signaling initial market penetration. Continuing forward, next-generation engines can be designed specifically as topping cycles for an organic Rankine (bottoming) cycle, with both power sources integrated into advanced hybrid drivetrains. [ABSTRACT FROM AUTHOR]

The ultra-low NOx emission limits for heavy and mid-duty vehicles, which are expected to be imposed in both Europe and the USA by 2027, together with the enforcement of continuous decrease in CO2 emission levels, make the need for adoption of newer technologies in the automotive industry imperative. To achieve low tailpipe NOx emissions, the accelerated warm-up of the exhaust aftertreatment system is of great importance. On the other hand, the thermal management strategies applied for this purpose result in fuel consumption penalty and consequently higher CO2 as it can be widely found in the literature. Thus, the use and optimization of advanced thermal management technologies is critical to decrease the NOx– fuel penalty trade-off on the basis of complete driving cycles. In the present work an integrated modeled-based approach is implemented by coupling advanced, predictive 1D engine, and aftertreatment simulation models which are extensively validated via dedicated experimental data. The main goal of this approach is to define and investigate multiple engine or aftertreatment-based thermal management technologies, as well as a combination of them, creating a more efficient warm-up mode for the engine. Thermal measures such as cylinder deactivation, retarded start of the main injection, late intake valve closing (Miller cycle), intake throttling, elevated idle speed, and secondary fuel injection upstream the DOC are evaluated for their effect on the exhaust system heat-up time, the fuel consumption penalty and more importantly, for their impact on the tailpipe NOx emissions calculated by this holistic simulation approach. [ABSTRACT FROM AUTHOR]

Aviation is undergoing significant sustainability issues, making energy efficiency and emissions concerns crucial. This paper examines the energy efficiency patterns of flights departing from 20 airports in Saudi Arabia from 2017 to 2021, considering the influence of the COVID-19 outbreak and the efficiency of the aviation industry. The study assesses energy efficiency by analyzing historical patterns, the hypothetical situation of what could happen in the absence of the COVID-19 pandemic, and the actual situation materialized within the Saudi aviation sector. The findings suggest that despite disruptive events, such as the pandemic and its management practice, aviation has improved its energy efficiency, with flights at some airports experiencing significant improvements due to effective management practices derived from changing previous conditions. This research contributes to the ongoing discourse concerning energy efficiency in aviation and supports the development of policies and measures to address energy and environmental-related challenges in the short and medium term.

Fuel consumption optimization is a critical field of research within the automotive industry to meet consumer expectations and regulatory requirements. A reduction in fuel consumption can be achieved by reducing the energy consumed by the vehicle. Several subsystems contribute to the overall energy consumption of the vehicle, including the air conditioning (A/C) system. The loads within the A/C system are mainly contributed by the compressor, condenser fan, and underhood aerodynamic drag, which are the components targeted for overall vehicle energy use reduction in this paper. This paper explores a new avenue for A/C system control by considering the power consumption due to vehicle drag (regulated by the condenser fan and active grille shutters (AGS)) to reduce the energy consumption of the A/C system and improve the overall vehicle fuel economy. The control approach used in this paper is model predictive control (MPC). The controller is designed in Simulink, where the compressor clutch signal, condenser fan speed, and AGS open-fraction are inputs. The controller is connected to a high-fidelity vehicle model in Gamma Technologies (GT)-Suite (which is treated as the real physical vehicle) to form a software-in-the-loop simulation environment, where the controller sends actuator inputs to GT-Suite and the vehicle response is sent back to the controller in Simulink. Quadratic programming is used to solve the MPC optimization problem and determine the optimal input trajectory at each time step. The results indicate that using MPC to control the compressor clutch, condenser fan, and AGS can provide a 37.6% reduction in the overall A/C system energy consumption and a 32.7% reduction in the error for the air temperature reference tracking compared to the conventional baseline proportional integral derivative control present in the GT-Suite model.

A significant number of aviation incidents is related to loss of control in flight and controlled flight into terrain (LOC-I, CFIT, LALT categories). Investigation of these aviation incidents has revealed that these incidents often occur due to the need for rapid changes in flight routes as a result of detecting obstacles, such as thunderstorms, along the aircraft's path. During the determination of alternative routes to circumvent the encountered obstacle, as well as during the implementation process of the chosen rerouted route, the flight crew makes errors due to increased psycho-physiological workload and time constraints. This article presents an approach to the automatic rerouting of the aircraft's flight route to avoid obstacles detected during flight. The algorithm proposed by the authors allows for evaluating the safety of the original route, calculating alternative route options to bypass the obstacles encountered during flight, verifying their feasibility considering the aircraft's flight technical characteristics and control parameter limitations, and selecting the optimal rerouted route based on specific criteria, such as minimizing the increase in the flight route length, reducing additional fuel consumption, time required for implementing the new flight route, etc. Examples of rerouting the flight route of a hypothetical aircraft with detected obstacles along the flight path are provided in the article to demonstrate the algorithm's functionality. It is shown, in particular, that in the considered example, the shortest route for obstacle avoidance is not optimal in terms of time. It is also demonstrated that the safety of flying along the identified alternative rerouted routes depends, among other factors, on the selected flight speed. Therefore, for each calculated rerouted route, the algorithm determines a range of speeds within which the implementation of the obtained rerouted route is possible. This highlights the complexity and non-triviality of the pilot's task of autonomously finding a safe obstacle avoidance route on board the aircraft.

The increasing deployment of CubeSats in space missions necessitates the development of efficient and reliable orbital maneuvering techniques, particularly given the constraints on fuel capacity and computational resources. This paper presents a novel two-level control architecture designed to enhance the accuracy and robustness of CubeSat orbital maneuvers. The proposed method integrates a J2-optimized sequence at the high level to leverage natural perturbative effects for fuel-efficient orbit corrections, with a gated recurrent unit (GRU)-based low-level controller that dynamically adjusts the maneuver sequence in real-time to account for unmodeled dynamics and external disturbances. A Kalman filter is employed to estimate the pointing accuracy, which represents the uncertainties in the thrust direction, enabling the GRU to compensate for these uncertainties and ensure precise maneuver execution. This integrated approach significantly enhances both the positional accuracy and fuel efficiency of CubeSat maneuvers. Unlike traditional methods, which either rely on extensive pre-mission planning or computationally expensive control algorithms, our architecture efficiently balances fuel consumption with real-time adaptability, making it well-suited for the resource constraints of CubeSat platforms. The effectiveness of the proposed approach is evaluated through a series of simulations, including an orbit correction scenario and a Monte Carlo analysis. The results demonstrate that the integrated J2-GRU system significantly improves positional accuracy and reduces fuel consumption compared to traditional methods. Even under conditions of high uncertainty, the GRU-based control layer effectively compensates for errors in thrust direction, maintaining a low miss distance throughout the maneuvering period. Additionally, the GRU’s simpler architecture provides computational advantages over more complex models such as long short-term memory (LSTM) networks, making it more suitable for onboard CubeSat implementations.

This study investigates the effects of varying waste swine oil biodiesel blends on the emission characteristics and efficiency of a compression ignition (CI) engine. Through a series of controlled experiments, the engine was operated under a constant load of 25% across different speeds ranging from 1200 to 1800 rpm. This study meticulously recorded the emissions of carbon monoxide (CO), hydrocarbons (HC), carbon dioxide (CO2), nitrogen oxides (NOx), and particulate matter (PM), along with performance metrics, including Brake Specific Fuel Consumption (BSFC) and Brake Thermal Efficiency (BTE). The results revealed a clear inverse relationship between biodiesel blend percentage and emissions of CO, HC, and PM. CO emissions decreased from 0.76 at 1200 rpm to 0.22 at 1800 rpm for the B80 blend, compared to pure diesel. Similarly, HC emissions showed a decline from 36 to 20 for the B80 blend. Conversely, CO2 and NOx emissions increased in higher biodiesel blends, with CO2 peaking at 2.9 for the B80 blend and NOx emissions rising from 103 for pure diesel to 165 for the B80 blend. PM emissions also decreased with higher blends, from 15 in pure diesel to 10 in the B80 blend. This comprehensive analysis reveals that while biodiesel significantly reduces specific emissions, it also poses challenges in terms of increased fuel consumption and reduced thermal efficiency. The findings emphasize the need for advanced engine technologies and optimization strategies to harness the full potential of biodiesel as a sustainable and environmentally friendly alternative to diesel. [ABSTRACT FROM AUTHOR]

The strengthening of regulations such as EEXI, EEDI, and CII on ship emissions is underway. Despite their application, objective comparisons of ships are hindered by diverse navigation patterns and varying velocity regulations in different seas and ports. Additionally, a lack of basic data impedes comparisons of the optimal design and objective energy efficiency for ships. To address these issues, representative sailing modes, similar to those in the automobile industry, are needed. However, there is no reference for marine applications. This study introduces a methodology for representative sailing modes using the Markov chain. A hundred candidate sailing modes were created, and representative modes were identified through an evaluation equation. All chi-square values for representative sailing modes are within 1%, indicating significant results. This study's findings can aid in designing optimized systems for new vessels and computing authorized fuel efficiency for vessels with diverse sailing patterns. [ABSTRACT FROM AUTHOR]

In recent times, the significance of advancing road transportation technologies has notably increased. This is mainly driven by the escalating need for road transportation systems that are not only safe but also environmentally sustainable. Moreover, enhancing fuel efficiency in road vehicles (i.e., automobiles) holds the potential to contribute significantly to the reduction of a country's economic vulnerability (i.e., improved energy security), by reducing the reliance on energy imports. While research reports and scientific journals provide valuable information on automobile fuel consumption, it is essential to continually update our understanding of the factors that influence it. This document aims to review and describe the various factors, both direct and indirect, that play a role in an automotive's overall energy efficiency and fuel consumption. [ABSTRACT FROM AUTHOR]

Players involved in the global commercial aviation industry have committed to carbon neutral growth starting from 2020, and to a 50% reduction in emissions by 2050, even amid an expected growth in commercial demand during this period. Motivated by this challenging scenario, this study investigates the impact of the current aircraft incremental technological progress on greenhouse and local pollutant emissions, taking into consideration operational data from Brazilian air transport during the year 2018. A case study is conducted to estimate the emission efficiency of two different models of aircraft in the Airbus A320 family, which are one of the main parts of the commercial aviation Brazilian fleet. Emissions evaluated in the study are CO2, CH4, N2O, CO, VOC, SO2, NOx and PM2.5. In order to assess the emissions efficiency, the number of flights performed in the period, types of engines, consumption, distance flown, total weight transported and emission rates in different engine power configurations were collected for each aircraft model. Furthermore, a top-down methodology was applied to quantify the greenhouse emissions, and regarding the local pollutant emissions were performed a bottom-up approach dedicated to the different phases of the landing and take-off cycle. The results estimate a reduction of 28% in the average annual greenhouse gases emissions due to the gain in energy efficiency from the more recent generation of engines. In addition, they show that these engine improvements also provide a significant reduction in the emission of local pollutants mitigating the harmful effects on air quality in airport zones. [ABSTRACT FROM AUTHOR]

Pakistan is moving toward the large-scale use of coal. Coal plays a dominant role in Pakistan's energy mix and is estimated to reach 30% by 2030. The purpose of this study is to analyze coal imports and indigenous reserves in relation to CO2 emissions. In particular, this study constructs the logarithmic mean Divisia index (LMDI) method to see the impact of the factors, decoupling index for the economic relationship, and pollution from coal-fired power plants from 1986 to 2019. The empirical results show that 1) coal consumption and imports are interrelated, while coal production has had the lowest production level since 1986; 2) the energy intensity impact plays a medium role in decreasing coal utilization, followed by the coal share effect; however, the aggregated impact accounts for 0.023% of the total coal use; 3) the economic and population activity effects progressively increase with coal consumption by 0.25% and 0.35%, respectively, with the annual average growth; 4) only "three" decoupling states were observed: expansive coupling, expansive negative decoupling, and weak decoupling. Expansive negative decoupling occurred due to high energy share and energy intensity. Expansive coupling occurred only in 2001 due to rapid growth in coal proportion and a sluggish decrease in energy intensity, and weak decoupling showed a decoupling association between economic growth and coal utilization; and 5) the various coal compositions, such as moisture, volatile matter, fixed carbon, ash, and sulfur, can be evaded by 1.82, 4.83, 5.16, 1.43, and 0.39 Mt currently. Finally, environmental analysis recognized that implementing clean coal technologies significantly saves fuel and, consequently, reduces emissions. This study also discusses further policies. [ABSTRACT FROM AUTHOR]

The results of the analysis of the influence of the aerodynamic characteristics of the road train on its fuel efficiency are presented. Based on the analysis of known studies, the power balance equation and the known equation of road fuel consumption, it is shown that air resistance has a significant effect on fuel economy indicators. Through the analysis of the air resistance equation and taking into account known studies, it was concluded that one of the key parameters that affect the aerodynamics of the road train is the distance between the cab and the semi-trailer. The results of computer modeling of the aerodynamics of a two-track road train are presented. Based on the proposed model, it is shown that the distance between the cabin and the semi-trailer has a non-linear effect on the total air resistance expressed through the reduced pressure. On the basis of this, an assumption was made about the possibility of optimizing the specified distance according to the criterion of minimum air resistance. It has been established that the use of such technologies as aerodynamic panels can significantly improve the aerodynamic characteristics of a road train, which, in turn, will have a positive effect on fuel economy and other operational characteristics of the road train. A real example of how a decrease in the coefficient of ease of movement, which also takes into account air resistance, affects fuel consumption. It is shown that a decrease in the coefficient of ease of movement by only 0.04 units leads to a decrease in fuel consumption by 11%. It was concluded that the influence of the geometry of the road train, namely the distance between the cab and the semi-trailer, on the indicators of aerodynamics and fuel efficiency requires further research both by computer modeling and by researching physical models of road trains in a wind tunnel.

Due to growing environmental concerns and stringent emissions regulations, optimizing the fuel consumption of marine propulsion systems is crucial. This work deals with the potential in an LNG ship propulsion system to reduce fuel consumption through controlled load distribution between engines in Dual-Fuel Diesel Electric (DFDE) plant. Based on cyclical data acquisition measured onboard and using an optimization model, this study evaluates different load distribution strategies between setups according to the optimization model results and automatic (equal) operation to determine their effectiveness in improving fuel efficiency. The analysis includes scenarios with different fuel types, including LNG, MDO and HFO, at different engine loads. The results indicate that load distribution adjustment based on the optimization model results significantly improves fuel efficiency compared to conventional methods of uniform load distribution controlled by power management systems in almost all load intervals. This research contributes to the maritime industry by demonstrating that strategic load management can achieve significant fuel savings and reduce environmental impact, which is in line with global sustainability goals. This work not only provides a framework for the implementation of more efficient energy management systems on LNG vessels, but also sets a benchmark for future innovations in maritime energy optimization as well as in the view of exhaust emission reduction.

This article discusses the challenges facing public transport in Ukraine in terms of reducing fuel consumption and emissions. The absence or insufficient development of means and methods for monitoring driver behaviour, as well as high staff turnover, create significant difficulties in controlling drivers and vehicles. A conducted study in Lutsk, the administrative center of the Volyn region, analyzed the driving behavior of passenger buses in the city. Results showed that typical driving modes include idling (40%), acceleration (18%), driving at a constant speed (29%), and braking (13%). The study also revealed average accelerations and decelerations, and these results do not meet the requirements of ecological driving. The correlation between driver behavior and these dynamic acceleration and braking characteristics has been established. Possible causes for this phenomenon are discussed in the study. The article proposes the introduction of modern solutions to solve these problems. These solutions are Eco-Driving Assistance Systems (EDAS) or integrated systems, such as FleetControl from TRIONA, which can help learning operating conditions and reduce fuel consumption and emissions. These programmes can also serve as effective monitoring tools for individual drivers and transport companies. This paper describes these applications and reviews the research related to their use and development. In addition, the article highlights the importance of training drivers in eco-driving as a cost-effective method of improving fuel efficiency in transport companies. The paper concludes by emphasising the need for further research to fully understand the complexities of public transport in Ukraine and the potential benefits of introducing innovative technologies for a more sustainable and efficient future for the industry.

The Euro 6 emission standard requires compliance with tough legal exhaust emissions limits for newly registered vehicles and obligates light-duty vehicle manufacturers to respect the 160,000 km durability requirements for inservice conformity. Although there is no legal limit set for fuel consumption, manufacturers are obligated to decrease the carbon footprint of vehicle fleets in order to obtain carbon neutral mobility beyond 2035. The aim of this paper is to analyse the impact of various oils' and viscosity grades' degradation on the change in break specific fuel consumption (BSFC) measured over a standardized durability test cycle. Each oil candidate underwent 300 h of durability test running performed on a test bed without any oil changes. The purpose of the laboratory test was to reproduce the worst-case operating conditions and degradation process of the long-life engine oil type that can be experienced during extreme real life driving of a vehicle. In order to define the influence of the engine oil deterioration on the BSFC profile, the engine operation parameters were continually monitored throughout the test run. Additionally, chemical analysis of the oil was performed and the solid deposits formed on the turbocharger's compressor side were evaluated. The test results revealed differences up to 5% in the BSFC values between the oil candidates tested over the durability cycle. The observed BSFC increase was directly related to the decrease in engine efficiency and can cause higher fuel consumption of the engine, which in turn has an adverse effect on environmental protection goals. [ABSTRACT FROM AUTHOR]

PEM (Proton Exchange Membrane) fuel cells, which are commonly used in vehicles, are critical for sustainable transportation in the future. In this study, it is aimed to enhance the system efficiency of the PEM fuel cell and provide fuel economy. To achieve this goal, the hybrid energy system with a PEM fuel cell and battery pack is controlled with two different strategies. The first control strategy is designed using Fuzzy Logic (FL), while the other control strategy is designed with the classical on-off method with the 'Relay' block. Power output of the fuel cell is determined depending on the change in the charging state of the battery pack and the power consumed by the electric vehicle in this study. The aim is to provide that the fuel cell operates in a high-efficiency range and can generate enough power when needed. Vehicle and fuel cell modeling were per-formed in Matlab/Simulink environment. NEDC (New European Driving Cycle) and WLTP (Worldwide Harmonized Light Vehicles Test Procedure) driving cycles were considered and fuel cell efficiency and hydrogen consumption were compared at different state of charge values of the battery. The analyses were carried out over long distances by repeating the driving cycles. It was observed that fuzzy logic control provided 11.6% less fuel consumption than classic on-off control in NEDC and WLTP driving cycles repeated five times. The values obtained as a result of the study showed that fuzzy logic control is more advantageous to increase the energy efficiency of fuel cells. [ABSTRACT FROM AUTHOR]

This paper presents an assessment of the potential fuel burn savings offered by the transonic strut-braced-wing configuration within the single-aisle class of aircraft relative to a modern conventional tube-and-wing aircraft through aerodynamic shape optimization based on the Reynolds-averaged Navier-Stokes equations. A representative strut-braced-wing aircraft is first developed through conceptual multidisciplinary design optimization based on the Airbus A320neo, with current technology levels assumed. A concept for the conventional tube-and-wing configuration is also developed to represent the Airbus A320neo as a performance baseline. Single-point aerodynamic shape optimization is then performed on wing-body-tail models of each aircraft to address aerodynamic design challenges and to provide more accurate performance estimates. Results indicate that shock formation can be mitigated from the wing-strut junction of the strut-braced wing at Mach 0.78 and a relatively high design lift coefficient of 0.750, providing an 8.2% reduction in block fuel over a 1000 n mile nominal mission when compared to the conventional tube-and-wing aircraft. Multipoint aerodynamic shape optimization is then performed to build toward a more credible estimate of fuel burn performance, with results showing a reduction in the fuel burn savings to 7.8% at the nominal design point relative to the conventional tube-and-wing aircraft to maintain a 7.6-8.0% improvement over the envelope of operating conditions, which includes design points at even higher Mach numbers and lift coefficients. These results demonstrate the viability of the transonic strut-braced-wing configuration for transport aircraft within the single-aisle class and its potential for reducing commercial fleet fuel burn. [ABSTRACT FROM AUTHOR]

Owing to environmental regulations and energy issues, the development of low-emission and high-efficiency vehicles is required. Liquefied petroleum gas (LPG) is a representative low-pollutant fuel and the third most commonly used fuel for internal combustion engines worldwide. In this study, we propose to convert the existing gasoline direct injection (GDI) to liquefied petroleum direct injection (LPDI) as the simplest way to reduce pollutant emissions from the exhaust gases of internal combustion engine vehicle (ICEV). The conventional GDI engine fuel system was converted to an LPG system, and the pollutant emissions and three-way catalyst conversion efficiency were analyzed. As a result of fuel conversion, a phenomenon occurred in which the three-way catalyst did not operate normally under some operating conditions. By calibrating the fuel pressure signal by signal converter to increase the pressure in the high pressure fuel rail, the three-way catalyst was normalized. Finally, by adjusting the fuel rail pressure of the LPDI conversion engine, the optimization was performed, and the engine performance was evaluated. [ABSTRACT FROM AUTHOR]