Technical Sciences

Application of frame motion and mesh motion techniques for determining the torque of a Rushton turbine

Michał Duda, Wojciech Sobieski — Thu, 19 Mar 2026 00:00:00 +0000

The article presents experimental and numerical studies of the torque of a Rushton turbine impeller operating in a cylindrical tank without partitions. The analyses were carried out on a laboratory scale for one system geometry and five impeller rotational speeds. Numerical calculations were performed using the Multiple Reference Frame (MRF) and Sliding Mesh (SM) methods in combination with the Volume of Fluid (VoF) model, with an analysis of the influence of mesh density performed prior to the main calculations. The simulations were performed in the ANSYS Fluent environment, while the experimental measurements were performed using the IKA EUROSTAR 60 control drive. The results obtained showed good qualitative agreement of the torque characteristics as a function of rotational speed, with simultaneous quantitative discrepancies consisting in obtaining higher torque values in numerical simulations compared to the experiment. These discrepancies may result from the limitations of the RANS approach in mapping global vortex motion and free surface deformation of the liquid, as well as from measurement uncertainties, which indicates further directions for research.

Comparison of computational efficiency of various implementations of FFT algorithm on DSP processor

Jakub Banach, Michał Śmieja — Wed, 22 Apr 2026 00:00:00 +0000

The ongoing development of hardware solutions enabling more efficient signal processing is influencing the development of capabilities for reasoning about the state of technical objects. At the same time, solutions for processing data in close proximity to the technical object – edge computing – are becoming more widespread. In an era of new possibilities and expectations regarding signal processing, it is necessary to select a computing unit and a computational algorithm implementation tailored to the process being carried out. This article examines the performance of various implementations of the commonly used FFT algorithm in terms of execution time and energy consumption on a selected computing unit – the ADSP-SC589 DSP controller. The study examined implementations using the SIMD architecture of the computing unit, as well as implementations using a hardware calculation accelerator built into the device structure. The obtained results suggest significant improvement in signal processing algorithm execution time (around 40 times shorter) of SIMD based implementation as well as minor reduction of power consumption, as well as very high improvement in execution time of hardware accelerator based implementation (around 1000 times shorter) at cost of increased power consumption. The results suggest various implementations significantly differ from each other, and show clear benefits of code optimization based on specific architecture as well as hardware acceleration.

Verification of the symbiosis of artificial intelligence and nature-based solutions as a development premise in the shipbuilding industry

Halina Tańska, Jolanta Sala, Bartosz Janiszewski — Mon, 25 May 2026 00:00:00 +0000

The shipbuilding industry in Poland, Europe and the United States has been struggling in the 21^st century with asymmetric competition from Asia. For several renowned shipyards – including those in Gdansk – identifying pathways for development and creating innovative solutions has become essential for survival. This article presents the dilemmas and research outcome that form part of the preparation for a project aimed at developing an innovative solution grounded in nature-based technologies supported by artificial intelligence. The project on efficient water management for planned production processes in the shipyard constitutes one component of the broader EcoTech initiative, which addresses a wider set of developmental needs of the shipbuilding sector, particularly in Gdansk. This article tackles the challenge of holistically identifying the wide spectrum of developmental conditions as well as the methodological responsibility guiding research and development activities intended to generate breakthrough solutions with business significance.

Efficiency of brewery wastewater treatment

Mon, 25 May 2026 00:00:00 +0000

Wastewater is contaminated liquids discharged from homes and industrial plants. A wastewater treatment plant is a complex of basic technological facilities directly used for wastewater treatment, along with auxiliary facilities located on a shared site, necessary for supplying electricity and water, creating appropriate operating conditions, and maintaining the treatment plant. Brewing industries produce wastewater with high organic loads, characterized by high values of parameters such as BOD₅and COD. For this reason, these plants typically have their own wastewater treatment systems or cooperate with local municipal wastewater treatment plants. There is growing interest in energy recovery in this industry, for example, through the use of biogas generated during treatment processes, which contributes to cost reduction and a reduction in pollutant emissions. However, the variable composition and load of wastewater remain a challenge, as does the need to properly combine mechanical, biological, and chemical methods to reduce waste volume and its environmental impact. Preparations containing surfactant compounds are used to clean these types of industrial installations. The work was supplemented with an analysis of the content of anionic and nonionic surfactants. Their levels in wastewater – both raw and treated – can be determined using dedicated cuvette tests and the MBAS (for anionic surfactants) and BiAS-thio (for nonionic) methods. The assessment of treatment plant efficiency was based on the pollution reduction index, comparing the content of specific parameters before and after treatment, and the permissible pollutant values in treated wastewater discharged to surface waters.

Regional differentiation of pedestrian-caused road accidents in Poland: causes, severity, and safety implications

Piotr Gorzelanczyk, Edgar Sokolovskij — Wed, 03 Jun 2026 00:00:00 +0000

Despite a long-term decline in the total number of road accidents in Poland, pedestrian safety remains a serious public health concern. Pedestrians continue to account for a substantial share of fatalities and serious injuries, with careless entry onto the roadway and illegal crossing being the dominant behavioral causes. This study investigates regional differences in pedestrian-caused road accidents across all 16 Polish provinces between 2018 and 2024.

The analysis is based on official police accident statistics and applies descriptive statistics, normalized safety indicators (accidents per population and fatalities per accident), and correlation analysis to assess relationships between accident causes and their consequences. The results show strong regional differentiation. Highly urbanized provinces such as Mazovian and Silesian record the highest absolute number of pedestrian accidents, while eastern provinces, including Lublin and Subcarpathian, exhibit significantly higher fatality rates per accident despite lower incident counts.

Behaviors such as lying or sitting on the roadway are associated with the highest accident-to-incident ratios (up to 75%) and the highest mortality levels, reaching 50% of accidents. The findings demonstrate that accident frequency alone does not adequately reflect pedestrian safety and highlight the need for region-specific preventive measures. The results may support evidence-based regional road safety policies aimed at reducing pedestrian fatalities.

An assessment of the potential of Brown's Gas (HHO) to reduce diesel fuel consumption in small engines

Norbert Dudda, Michał Janulin — Fri, 21 Aug 2026 00:00:00 +0000

This study evaluates the effect of Brown’s gas (HHO), produced by water electrolysis, on diesel fuel consumption in a small compression-ignition engine driving a stationary generator set. The tests were performed under six electrical load conditions and three fuelling variants: diesel fuel only, diesel with approximately 117 l/h HHO, and diesel with approximately 140 l/h HHO. Diesel fuel consumption was measured gravimetrically, while HHO flow rate and electrolyzer electrical demand were monitored during the measurements. The results indicate that HHO addition may reduce the measured diesel fuel consumption under selected operating conditions; however, the magnitude of this reduction is limited and depends on load and HHO flow rate. Moreover, the electrical power required to generate HHO exceeded the energetic benefit resulting from the observed diesel fuel savings. Therefore, the tested on-board-type HHO system should not be considered energetically or economically justified when powered from the vehicle electrical system. The study contributes a practical assessment of a commercially available HHO kit under stationary-engine operating conditions, with particular emphasis on the energy balance of the system.