The variability of primary emission signals from high-pressure turbine blades originating from the same stage of an SO-3 turbojet engine was evaluated using Laser Ablation coupled with Microwave-Induced Plasma Optical Emission Spectrometry (LA-MIP OES). Forty turbine blades were investigated, with one analytical measurement performed for each blade. Direct solid sampling enabled multi-element analysis without chemical sample preparation. The primary emission signal intensities of nickel, molybdenum, chromium, cobalt, and aluminum were statistically evaluated using mean values, standard deviations, coefficients of variation, interquartile ranges, confidence intervals, and boxplot analysis. The coefficients of variation ranged from 3.44% to 11.60%, indicating relatively low variability of the measured emission signals among the investigated blades. The lowest variability was observed for cobalt, nickel, and molybdenum, whereas chromium exhibited the highest dispersion. The results demonstrate a high degree of uniformity of the measured emission signals and indicate the potential of LA-MIP OES for comparative assessment of turbine blade materials.
The fuel system of a diesel engine is a crucial component that significantly impacts the economic and technical performance, as well as the quality of exhaust emissions released into the environment. Improving fuel injection pressure, combined with changes in the fuel injection rules, the number of fuel injections in a cycle, and the geometric dimensions of the injectors, helps improve efficiency, reduce harmful emissions, and lower fuel consumption. This study evaluated the effect of the shape of the fuel injection characteristic at injection pressures up to 350 MPa, with the intake air pressure maintained at 0.25 MPa, using a 3D AVL Fire model. The results showed that at ultra-high fuel injection pressures, the amount of particulate matter from the diesel engine was very small, ranging from 0.0012 to 0.0062 g/kWh. By changing the distribution rules, the minimum amount of NOx was formed, corresponding to the case where the injection velocity was highest in the initial phase (case 1 and a value of 9.51 g/kWh) and gradually decreased in the latter phase of the injection process (case 5 and a value of 21.01 g/kWh). In addition, engine power decreased by 1.9% and fuel consumption increased by 1.8%. Due to inadequate fuel mixing between zones and fuel being mixed leaner than the combustion limit when increased injection pressure with a large injection volume in the initial phase. As a result, the maximum HC amounts increase by 4.8 times and the maximum CO amounts increase by 1.6 times compared to other injection cases.
This article presents an analysis of the operation of the electric motor, generator, and internal combustion engine within the hybrid powertrain system of a Toyota Corolla. To compare data regarding energy utilization from these sources, a specially designed diagnostic scanner was employed in our laboratory, enabling the capture of data from the vehicle's Controller Area Network (CAN). The tests were conducted on a laboratory chassis dynamometer, taking into account the NEDC (New European Driving Cycle) and WLTP (Worldwide Harmonised Light Duty Vehicle Test Procedure) protocols. Additionally, experiments were performed under real urban traffic conditions. The analysis of the collected data provided detailed insights into the operation of the aforementioned components, which are integral to the powertrain during characteristic driving scenarios. For selected test fragments, an analysis of energy consumption and recovery by the electric motor and generator is presented.
Internal combustion engines constitute one of the two fundamental propulsion categories used in unmanned aerial vehicles (UAVs). This article analyzes the occurrence and application of individual types of internal combustion engines across unmanned platforms, with particular emphasis on their influence on aircraft performance and mission profiles. The advantages and limitations of specific propulsion system configurations are identified in the context of unmanned aviation, including factors such as energy efficiency, mass, structural complexity, endurance, and acoustic and thermal signatures. In addition, representative UAVs employing different types of internal combustion engines are presented, illustrating the practical implications of propulsion system selection in real-world operational applications.
Aircraft noise is one of the most significant environmental concerns around airports, generating both social conflicts and financial consequences. This study examined how the fleet composition influences daily exposure to aircraft noise in the vicinity of Poznań-Ławica Airport, focusing on two widely operated aircraft types: the Boeing 737-800 and the newer 737 MAX 8. Measurements were carried out at six monitoring points during 78 operations, and the analysis was based on the sound exposure level expressed on the physical scale and in decibels. The results show that the 737-800 consistently produces higher noise levels than the MAX 8, with mean LASel values of 0.89 Pa²·s (94.5 dB) compared to 0.57 Pa²·s (92.6 dB), a difference of 56%. The gap is particularly evident during take-off, where the 737-800 exceeds the MAX 8 by 137% (2.7 dB). Regression analysis confirmed a decreasing trend in SEL with increasing altitude; in the revised analysis, this dependence is modeled using a log-distance function in dB units, with altitude treated as a proxy for source–receiver distance. The simulation of nine fleet composition scenarios for a representative month showed that increasing the share of MAX 8 aircraft substantially reduces the number of days when the daily equivalent sound level (LAeqD) exceeds the legal threshold of 60 dB. Economic analysis using official Polish penalty tariffs for 2025 also showed that monthly environmental fines could be reduced by up to 69% if the fleet were fully modernised to MAX 8. Even partial renewal, with a 60–70% share of MAX 8, reduced costs by 60–70% relative to a fleet dominated by the 737-800. These findings highlight that fleet modernisation is a highly effective strategy for reducing community exposure to aircraft noise and mitigating the financial burden on airports, although the analysis was limited to daytime operations and one seasonal period.
