Communications - Scientific Letters of the University of Zilina - Latest articles
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Effects of Movement Direction through a Switch on Accelerations and Natural Frequencies of a Pneumatic Suspension of High-Speed Rolling StockMechanical Engineering in Transport
Andrii Kuzyshyn, Vitalii Kovalchuk, Yuriy Royko
Communications - Scientific Letters of the University of Zilina 2025, 27(1):B53-B64 | DOI: 10.26552/com.C.2025.007 
The research object is a pneumatic spring of the second stage of spring suspension of the high-speed railway rolling stock in movement conditions by a switch. Full-scale dynamic tests of a pneumatic spring for the high-speed railroad rolling stock were carried out. It was found that the average values of vertical accelerations in the trailing and facing directions in the wind turbines moving by the switch are 1.307 m.s-2 and 1.279 m.s-2, respectively. The ratio of the average values of longitudinal accelerations in the trailing and facing directions within the wind turbines is 1.01, and at the wind turbine bases is 2.15. It is...
Technical Condition Assessment and Modelling of Reed Valves in Vehicle Engine Intake SystemsMechanical Engineering in Transport
Oleksandr Kravchenko, Alexander Khrulev, Juraj Gerlici, Oleksii Saraiev, Serhii Danets
Communications - Scientific Letters of the University of Zilina 2025, 27(1):B41-B52 | DOI: 10.26552/com.C.2025.006
The purpose of the study was to evaluate the effectiveness of using a simple reed valve model of an engine with periodic workflow. To achieve this purpose, models of the reed valve have been developed and determined that the quasi-stationary model allows one to find the air flow through the reed valve with an accuracy of 5-6%. The limits of permissible values, at which the model has a minimal error, correspond to Strouhal number of 0.2-0.3. This data confirmed that with proper consideration of the existing limitations, the quasi-stationary model gives results close to those provided by the complex dynamic models.
Comparative Estimation of Maneuverability of the Multi-Track Road Trains of Different Layout SchemesMechanical Engineering in Transport
Volodymyr Sakhno, Igor Murovanyi, Oleksandr Razboinikov, Olekcii Palamarchyk, Valerii Dembitskyi
Communications - Scientific Letters of the University of Zilina 2025, 27(1):B30-B40 | DOI: 10.26552/com.C.2025.005
Today, in the constructions of multi-link road trains, two main layout schemes are used, as a rule - trailer (car + n trailers) and semi-trailer (tractor car + n semi-trailers). Previously conducted studies established that the maneuverability indicators of the road trains can be determined on wheels rigid in the lateral direction, that is, according to kinematic models, which are based on the angles of assembly of the road train links. These angles are defined for both a three-link trailer and a semi-trailer vehicle train, for different locations of the extended link. For the semi-trailer road trains, the requirements for maneuverability are not met,...
Cleaning Dusty Air Flow with a Rotary Cyclone from Dispersed ParticlesMechanical Engineering in Transport
Oleksandr Kravchenko, Oleksiy Bazhynov, Ján Dižo, Yevhen Haiek, Miroslav Blatnický
Communications - Scientific Letters of the University of Zilina 2025, 27(1):B21-B29 | DOI: 10.26552/com.C.2025.004
The research presented in this article is aimed to show the prospective direction of increasing the efficiency of cleaning dusty air flows from light impurities and dust on mobile grain separators by using a rotary cyclone with a multi-disc after cleaner. An increase in the efficiency of the process of cleaning the dusty air flow in dust collectors is provided by an additional effect on dispersed particles for their intensive redistribution in the working areas. The developed rotary cyclone has two working zones: the main zone and the post-cleaning zone. The rotary cyclone consists of a bladed impeller, a main cylindrical channel, a sedimentation chamber...
Analysis of Hybrid Spectrum Sensing in Cognitive Radio Using Hybrid ApproachesManagement Science and Informatics in Transport
Haribhau Ashok Shinde, Sandeep Garg
Communications - Scientific Letters of the University of Zilina 2025, 27(1):E1-E10 | DOI: 10.26552/com.C.2025.003
Cognitive radio (CR) technology enables dynamic spectrum access to meet the growing demand for wireless communication. This study investigates spectrum sensing methods, specifically energy detection (ED) and matched filter detection (MFD), within hybrid strategies. A novel hybrid MFD method was developed and evaluated via MATLAB simulations, analyzing factors like sample size, signal-to-noise ratio (SNR), and false alarm probability. Results reveal that ED has a higher miss-detection rate compared to MFD and the proposed hybrid method, which performs particularly well under low sample counts and SNR conditions. This research enhances spectrum sensing...
Research on Soil Cutting with a Flat Cutter Using a Simulation ModelMechanical Engineering in Transport
Asset Altynbayev, Alexandr Ganyukov
Communications - Scientific Letters of the University of Zilina 2025, 27(1):B12-B20 | DOI: 10.26552/com.C.2025.002
The research aims to develop an algorithm for modelling the process of cutting an infinite volume of soil with a flat cutter in the Abaqus software package. The hypothesis of the existence of energy and volume of resistance to cutting is proposed. The analysis of shock wave distribution in the soil volume is performed. Boundary conditions for the soil volume model are determined, as well as for a flat cutter with linear motion. Stress gradients in the soil during its deformation are determined. Confirmation of the hypothesis about the existence of energy and volume of resistance to cutting was obtained. A logarithmic regression equation was derived...
Modelling, Simulation and Experimental Verification of a 3 DOF Moving Platform with Parallel Kinematics and Electro-Hydraulic Proportional / Servo Control SystemMechanical Engineering in Transport
Ezz Eldin Ibrahim, Ahmed Azouz, Tarek Elnady, Mohamed Saffaa Hassan, Ibrahim Saleh
Communications - Scientific Letters of the University of Zilina 2025, 27(1):B1-B11 | DOI: 10.26552/com.C.2025.001
Hydraulic motion platforms are widely utilized in various environments due to their capacity to bear heavy loads and provide long actuator strokes. The predominant control system employed for hydraulic motion platforms is the electro-hydraulic servo system (EHSS) due to its high accuracy and robustness. However, compared to other types of hydraulic valves, the electro-hydraulic servo valve (EHSV) is less durable. An alternative system to EHSS is the electro-hydraulic proportional system (EHPS), which employs an electro-hydraulic proportional valve (EHPV) instead of the EHSV. The EHPV resolves the durability issue at the expense of accuracy and system...