Modeling natural convection from steel panel radiators presents a significant scientific and technical challenge. When heating the radiator's vertical surface, a boundary layer of warm air forms and ascends along the wall. Flow remains typically laminar in the lower section, but as the boundary layer develops, it becomes unstable and transitions to turbulence. Beyond temperature head, transition conditions depend critically on heater geometry. Height, panel count, and vertical finning elements directly impact convective flow formation, where optimized geometry promotes early laminar-turbulent transition and intensified convection. While heat transfer is conventionally evaluated through dimensionless correlations (with Grashof numbers near 10⁹ serving as critical transition thresholds for vertical surfaces, corresponding to ~70°C temperature head at 0.5–1 m height), real-world radiator operation maintains laminar flow in lower zones with upper-height transition to turbulence – a process indeterminable via correlation methods. This study proposes a CFD simulation methodology calibrated against laboratory tests conducted per GOST R 53583-2009, enhancing computational result reliability. The calibrated numerical model ensures high-precision prediction of integral heat emission characteristics. CFD implementation enables preliminary radiator behavior analysis without physical prototyping through parametric variation of geometry and thermal properties. The model is readily parameterized by panel dimensions, finning configuration, and material/medium properties, ensuring computational repeatability across configurations. The proposed calibration method (achieved by imposing experimentally measured heat flux values per GOST R 53583-2009) enhances accuracy in predicting radiator's integral performance metrics and improves model-experiment alignment. This approach guarantees computational reproducibility and flexibility in simulating diverse designs (panel sizes, fin arrangements, materials). Validation challenges persist: Absence of experimental temperature/velocity fields complicates mesh sensitivity analysis, while single-dataset calibration risks model overfitting. Nevertheless, this methodology proves strategically valuable for transitioning toward digital certification of heating devices, as it substitutes physical testing with numerically derived integral parameters of comparable accuracy.

Keywords: heating devices, natural convection, free air flow, heat transfer efficiency, laminar-turbulent transition

The spatio-temporal dynamics of plasma parameters was numerically investigated, and the radiation parameters were calculated for a strontium vapor laser (λ=430.5 nm SrII) under optimal conditions of active medium pumping, which we found experimentally. The analysis of the obtained results showed that under the conditions of excitation of a pulse-periodic discharge in the active element, which provide the maximum pumping rate of SrII levels due to impact-radiation recombination, a sufficiently high degree of spatial homogeneity of plasma in the active medium is realized, which is necessary to achieve high output parameters of laser radiation. Such conditions include the partial pressures of the components of the Sr-He working mixture, the pulsed energy input into the active medium, and the pulse repetition rate. The research results can serve as a guideline for optimizing the operating modes of recombination lasers.

Keywords: strontium vapor laser, recombination pumping, numerical modeling, optimization

The assessment of the properties of urbanized territories or plots is necessary to determine the most effective use of them and to determine the cadastral or market price. A comprehensive model for assessing the properties of urbanized territories is presented, which is a multiplicative model consisting of two models: an additive model for assessing the properties of the plot under consideration and an additive model for assessing the influence of external factors determined by the adjacent territory. This multiplicative combination of additive models allows for the differentiated determination of the best alternative for different types of plot use based on the influence of internal and external factors when comparing multiple plots at different stages of a development project. To do this, the preference coefficients are calculated using the ratio of the integral estimates of the compared areas. If there are several areas, they can be selected using pairwise comparisons and the analysis hierarchy method.

Keywords: urbanized territory, property valuation, internal and external factors, additive and multiplicative models, development project

Ensuring high quality indicators of paper products manufactured on modern wide-format paper machines requires the use of systems for precise control of the main parameters: weight of 1 m2, humidity and thickness. The technological complexity of this task is due to the need for simultaneous control of numerous actuators across the width of the paper web. The presented study demonstrates an innovative system for controlling the main parameters of paper quality in the transverse direction, built using neural network technologies. The developed solution ensures high accuracy of parameter control in comparison with traditional control methods, which is confirmed by the results of experimental testing in production conditions.

Keywords: pulp and paper production, paper machine, web width control; neural controller, interconnected control, distributed parameter control object, actuator, control system, paper web

In the production of bitumen-mineral mixtures, it is proposed to use artificial granite as a filler - waste from the production of porcelain stoneware (OPK). To assess the durability of road and pavement network coatings, a method for determining the aging coefficient of bitumen-mineral mixtures was developed. It was concluded that in the presence of sand from the screenings of crushed porcelain stoneware, the bitumen binder of fine-grained BMS is less susceptible to aging processes.

Keywords: artificial granite, aging of bitumen binder, aging coefficient, sand from crushing screenings

The article presents the results of statistical analysis of the orthotropy coefficient of a multilayer cylindrical shell under compressive loads. The orthotropy coefficient is defined as the ratio of the critical load for asymmetric buckling of the shell to the critical load for axisymmetric buckling of the shell. It is assumed that the structure web is formed by laying longitudinal, annular and double spiral layers. The input values ​​are the elastic characteristics of the monolayers, assuming that these characteristics are random variables subject to the normal distribution law. The output value is the orthotropy coefficient. All calculations were performed in the MAXIMA computer algebra system. Two most common shell models were investigated: equally rigid and quasi-isotropic. It was found, in particular, that for shells with a quasi-isotropic structure, the orthotropy coefficient is “determined”.

Keywords: statistical modeling, monolayer, multilayer shell, composite material, elastic properties, stability, buckling, critical load, orthotropy coefficient, MAXIMA, Monte Carlo method.

The article presents the concept of ensuring reliability during the operation of oil pipelines in an active tectonic fault zone. Possible solutions to this problem are considered. It is noted that at the present stage in the Russian regulatory and technical documentation, when calculating pipelines for seismic effects, a sharp displacement of the soil is not taken into account, leading to a violation of their design position. Using the example of the research object, changes in the stress-strain state of a pipeline with specified pipe wall thicknesses and plate displacement during an earthquake were considered. The minimum distances for the installation of shut-off valves in the area of the pipeline passing through a tectonic fault were determined. The total amount of economic and environmental damage from possible accidents on the oil pipeline under study has been determined, which allowed us to conclude that an integrated approach is needed to ensure the reliability of oil pipelines in the zone of an active tectonic fault.

Keywords: oil pipeline, active tectonic fault, reliability, stress-strain state, accident, shut-off valves, displacement of plates of the earth's crust

Increasing the accuracy of steady-state calculation is possible by taking into account the thermal processes occurring in electrical energy conductors. The wind flow velocity, in turn, is of significant importance in determining the conductor temperature. In this paper, the values of wind speed for an 11-year period are considered. The time series is analyzed and the prediction models of the target variable are tested and the prediction results are compared.

Keywords: power grid mode calculation, thermal processes, wind flow velocity, prediction models, feed forward neural network, ensemble methods

This article explores visual data processing methods for underwater navigation and environmental reconstruction, based on modern approaches in computer vision and robotics. A system implemented in the ROS (Robot Operating System) environment is proposed, enabling simultaneous localization and mapping (SLAM) in underwater conditions. The system evaluation methodology includes virtual experiments using the Gazebo simulator, which replicate realistic underwater operational scenarios. The study demonstrates the feasibility of integrating stereo cameras, confirms the effectiveness of image processing methods in underwater environments, and presents quantitative metrics for navigation accuracy and object reconstruction. The results validate the proposed solutions as promising for real-world applications in autonomous underwater exploration.

Keywords: underwater navigation, environmental reconstruction, computer vision, visual odometry, SLAM, ROS, Gazebo, simulation, visual data, robotics

The article discusses the process of formation of cavitation bubbles. One of the effective designs of regulating equipment is an axial type valve, for which a mathematical description of the process of formation of cavitation bubbles has been developed. This description allows you to evaluate the bubble structure depending on the main operating and design dimensions of the valve.

Keywords: valve, cavitation bubbles, probability, functions

The article is devoted to the consideration of the features of using game theory to model review manipulation on marketplaces. In the course of the study, a model was proposed that is based on evolutionary theory and allows us to determine how susceptible buyers and marketplaces are to review manipulation, and what benefits all participants in these relationships receive. Special attention is paid to the audit that is conducted by the marketplace in relation to the processes of review manipulation by the seller, and the losses that the parties incur if it is detected.

Keywords: marketplace, reviews, buyer, seller, benefit

The article provides a diagram of the possible flooding zone for the area adjacent to the bridge crossing over the Bira River. The calculations were performed on the basis of topographic survey data of the research area in the specialized program "Morphostvor 1". Based on the constructed morph, a flood zone was determined at the Estimated 1% high water level, which was 55.05 meters in the 1977 Baltic Elevation System. Based on the data obtained, flooding of the right-bank floodplain of the river was noted. Bira, but the flooding zone does not reach directly to the territory of the village. The constructed flood zone is schematic in nature and is intended for visualization of the hydrological situation in the studied area, this flood zone cannot be used for design decisions.

Keywords: flooding zone, estimated high water level, bridge crossing, morph gap, Bira River

The work investigated the effect of the complex application of the nanomodifying additive "Taunit-M", superplasticizer SP-3 and steel fiber "Mixarm" with a diameter of 1 mm and a length of up to 54 mm. The dependence of the amount of introduced steel fiber on the strength characteristics of concrete was established. Data on the stability of the suspension of mixing water with a nanomodifier are given. An improvement in the intensity of concrete strength gain in the early stages of hardening from the introduced complex nanomodifying additive was determined.

Keywords: concrete, carbon nanotubes, ultrasonic dispersion, steel fiber, suspension stability, superplasticizer

The article considers a robotic control system for implementing the S-shaped movement of a snake robot, and evaluates the specifics of its use on a physical prototype. Since the snake robot is a complex composite structure, the assessment and assignment of a certain type of movement becomes one of the primary tasks in the development of this control system. The simulation model of the snake robot is implemented using mathematical modeling in the Russian software REPEAT. As a result of the simulation, it was found that the developed control system ensures the operability of the robotic system, ensures the accuracy of movement and adaptability to changing external conditions.

Keywords: mathematical modeling, simulation model, REPEAT, snake robot, wave motion control system, torque variation

Diagnosing the technical condition of complex objects and planning repair-restoration work is a pressing challenge in today’s economy. This paper presents an approach to solving this problem using an integral indicator developed by the authors: the Modified Technical Condition Index. A conceptual model for a continuous (cyclical) monitoring system of this integral indicator’s levels is proposed. To assess an object’s technical condition, a linguistic scale is introduced, which generates recommendations for repair-restoration actions. Additionally, a resource-constrained planning system for repair-restoration work is developed. The novelty of this work lies in the proposed methodology for creating an evaluative linguistic scale based on the integral indicator. This scale enables qualitative assessment of an object’s condition and provides actionable recommendations for repair-restoration efforts. The paper also addresses resource-constrained planning of repair-restoration work using the Modified Technical Condition Index for complex technical objects.

Keywords: express diagnostics, planning repair-restoration work, integral technical condition indicator, conceptual model of continuous (cyclical) monitoring, technical condition level assessment, technical condition quality evaluation, linguistic scale

The article proposes an approach to automate the detection of polishing defects in blades using luminescent testing (LUM). Instead of manual visual inspection, a system was developed that utilizes a deep learning neural network for defect segmentation on images and a robotic setup for precise positioning of the camera and the blank. This ensures the repeatability of the inspection. The relevance is driven by the industry's need for high-precision and reliable real-time quality control methods. The mathematical model of the process, software architecture, hardware components, and the data collection process for neural network training are described. The results of applying the system for defect detection are presented. The development optimizes polishing processes.

Keywords: industrial blade polishing, intelligent video analytics, robotic optical scheme, mathematical model of technological process, Lum control

The article is devoted to the consideration of approaches to the formation of a universal barrier-free recreational environment in the courtyards of apartment residential complexes. The relevance of studying the problem of courtyard spaces development is due to the transformations in the social structure of society that have occurred over the past forty years, rethinking the understanding of the universal recreational intra-block environment. The purpose of the research work was to develop a system of qualitative characteristics that correspond to the current demands of society for local recreation, providing a basis for planning an aesthetically attractive, comfortable and popular courtyard environment. The classification of the population (residents of a residential building) proposed in the article, made in accordance with the generalization of the updated needs for recreation, includes nine categories. This classification ensured the identification of the following qualitative characteristics of courtyard spaces: identity; variability; inclusiveness; capacity; isolation; communicativeness; flexibility; permeability; aesthetics; visuality; universality; safety; information content; environmental friendliness. The presented system of qualitative characteristics of the environment is a basic matrix for design solutions, allowing for a holistic consideration of the task of forming a courtyard, eliminating gaps in the proposal, and assessing its success.

Keywords: yard improvement, yard space, quality of spatial environment, universal urban design, barrier-free environment

Conductive polymer composite materials were successfully obtained using furan aminoplast as a binder, synthesized on the basis of a by-product of processing plant biomass into 5-hydroxymethylfurfural – humic resin and melamine (HumMel). Composites were made using different types of graphite (natural (NG), colloidal (CG)) as a filler. The filler content varied within 30–70 wt.%. It was shown that the conductivity of the composite material increases with the content of the conductive filler, and its strength changes in the opposite order. The best conductivity (contact resistance of 0.011 Ohm cm2) was shown by the polymer composite based on NG, containing 30% aminoplast. High strength (compression and bending strength of 55.2 and 38.6 MPa, respectively) was demonstrated by the composite with CG, containing 70 wt. of the polymer binder. The HumMel-NG-50 polymer composite meets the requirements for similar materials for the production of bipolar plates of fuel cells in terms of electrical conductivity (0.022 Ohm∙cm2) and mechanical strength (25.7 and 25.3 MPa in compression and bending, respectively).

Keywords: conductive polymer composite, furan aminoplast, carbon filler, bipolar plates, fuel cell

This article is devoted to the development of an innovative decision-making model in organizational systems based on the integration of stable, compositional and stylistic elements of communication. The paper analyzes modern theoretical approaches to decision-making modeling, such as the theory of bounded rationality and game theory, and highlights the role of stable and stylistic statements in effective communication within organizations. The authors propose a concept that includes genre features of communication and methods of cognitive modeling to improve the adaptability and effectiveness of management processes. Practical cases, in particular the use of models at IBM, confirm the possibility of optimizing processes and reducing decision-making time. The proposed model helps to improve the interaction of participants, improve the quality of solutions and the adaptability of organizations to rapidly changing environmental conditions.

Keywords: decision-making, organizational management system, the concept of decision-making modeling, genre-forming communication, decision-making modeling

The article is devoted to the issues of solving modern problems of development of the residential environment of new districts. The aim of the study was to create a proposal capable of providing a high-quality residential environment that positively influences the social microclimate and visual culture through people's perception of urbanized spaces using the aesthetics of classical architecture. It is substantiated that the greatest value for city residents is possessed by historical quarters of central zones formed in Russia from buildings with a characteristic classical order architectural form-building. New residential areas are often formed according to the principles of ghetto, with a priority focus on reducing the cost of investments in the construction of the facility and maximizing the developer's profit, which creates a stable trend towards social deprivation, the consequence of which are depressive psychological disorders and a decrease in the physical health of residents, stagnation and degradation of such territories in the future. An approach is proposed that allows minimizing the costs of constructing residential complexes using classical order architecture using modern additive technologies that can facilitate the implementation of decorative elements. This approach allows us to reveal a new stage in the development of order architecture, which will ensure historical cultural continuity and harmonization of the environment of new residential complexes, due to the properties of classical form-building.

Keywords: classical architecture, architectural order, residential complexes, classical form-building, aesthetics of the urban environment

The paper considers two machine learning methods for predicting the growth of watercut on an oil field with the calculation of basic convergence metrics.

Keywords: watercut, statistics, machine learning, time series, oil production

Digital twin technology shows significant potential in transforming various industries by enabling the modeling, analysis, and optimization of complex systems in real time. The integration of digital twin with the Industrial Internet of Things has opened up new opportunities for innovation and efficiency. In this regard, this article describes the methods and technologies that can be used to develop digital twins in Industrial Internet of Things applications and systems. Special attention is paid to such methods as: multiphysics and multiscale modeling, system life cycle method, data-driven modeling. Some technologies and architectures that can be used at three levels of creating a digital twin for Industrial Internet of Things systems are also described.

Keywords: digital twin, model, system, data, architecture, Industrial Internet of Things, communication, network, analysis, sensors