Acta Mechanica Slovaca - Latest articles
Results 61 to 72 of 72:
Metamaterials and Their Application in Biomedical Engineering
Barbara Schürger, Peter Frankovský, Ingrid Delyová, Jozef Živčák, Sára Janigová
Acta Mechanica Slovaca 2024, 28(2):44-50 | DOI: 10.21496/ams.2024.016 
Mechanical metamaterials have attracted attention due to their unique mechanical properties, such as low weight, adjustable stiffness, and auxeticity, making them excellent candidates for biomedical engineering innovative applications such as bone implants, vascular stents, and other healthcare applications. In this review, we will focus on the mechanical properties and behavior of these materials under different conditions, focusing on their application in the field of biomedical engineering.
Modelling of Pulsed Flow Effects Through the Exhaust System of a Turbocharged Engine Using Mixed Flow Turbine
Djamel Mazari, Mustapha Bordjane, Mohammed Hamel, Khadidja Boualem
Acta Mechanica Slovaca 2024, 28(2):28-43 | DOI: 10.21496/ams.2024.007
For some decades, reductions of fuel consumption and pollutant emission control have become the first requirement for internal combustion engines. Turbocharging is a promising way among many techniques to solve this problem since it leads to a downsized, lighter and more compact engine. Two important novelties can be listed in this study, the first is the development of a thermodynamic (zero dimensional) model for the gas expansion process through the exhaust system of turbocharged internal combustion engines. The latter is used to setup the unsteady state analysis using interpolation function for cyclic time of the internal combustion engine and the...
Impact of Casting Speed on Low Carbon Steel Manufacturing Process
Luboš Polcar, Marek Velička, Jan Růžička, Arasappan Yesudass
Acta Mechanica Slovaca 2024, 28(2):22-27 | DOI: 10.21496/ams.2024.013
Presented paper is focused on research of low carbon steel behaviour during continuous casting process. Research was conducted to investigate optimization opportunity of current casting process and possibility of increase in casting speed. Research was focused mainly on primary cooling area which is represented by mould. Mould insert was drilled, and thermocouples were installed in centreline of each side. Among others also temperatures and flow of cooling water, mould insert temperature and surface temperature of billet on the exit from the mould were measured. From conducted research it can be concluded that all following values exhibit strong linear...
A Numerical Study of the Innovative Design of Kinetic Static Mixer on Mixing Efficiency and Heat Transfer Improvement
Ourdia Benabdellaziz, Youcef Kamla, Ahmed Mouissi, Abdelkader Karas, Zied Driss
Acta Mechanica Slovaca 2024, 28(2):6-20 | DOI: 10.21496/ams.2024.008
This paper investigates the influence of rheological and geometrical properties on flow structures generated within a KENIC static mixer. The primary objectives are to examine the impact of these factors on fluid flow characteristics, particularly low-pressure conditions and mixing efficiency. To exanimate the performances of the different shapes, several parameters have been considered which consist on mixing index, thermal mixing index, hydrodynamic behavior and the probability density function. The investigation extends to encompass both Newtonian and non-Newtonian fluids, emphasizing Reynolds numbers ranging from 10 to 80. Comparative analyses...
Analysis of the Mixing of a Newtonian Material with a Strongly Viscous Material using CFD Numerical Modelling
Jan Adamec, Marian Bojko, Rostislav Zapletal, Josef Veselý
Acta Mechanica Slovaca 2024, 28(1):60-65 | DOI: 10.21496/ams.2024.002
This article deals with the mixing of a Newtonian material with a strongly viscous (non-Newtonian) material in a pipe with a static mixer. This problematic has a practical application in the food industry. CFD software ANSYS Fluent was used for numerical modeling. The mathematical model is defined using the basic balance equations, including the equation for species. The viscosity for a non-Newtonian highly viscous material (the working material) is defined using the Herschel-Bulkley model. A 3D computational model of a pipe with a static helical mixer is created in the DesignModeler program, which is part of the ANSYS software. The computational mesh...
Absorption Potential of Modern Steels when used for the Car-body Evaluated by the 3-point Bending Test with Stretching
Marek Buber, Emil Evin, Miroslav Tomáš
Acta Mechanica Slovaca 2024, 28(1):52-59 | DOI: 10.21496/ams.2024.015
Beside the active safety components of the car, the passive safety elements incorporated in the car-body structure are important too. To ensure passenger safety during a car accident, advanced materials are used in deformation zones. The article deals with testing the material's absorption ability by a 3-point bending test with stretching. The test allows simulating material behaviour during bending load when combined with stretching and determining the properties of the metal sheets, such as the absorption potential of the material and stiffness constant. The purpose of this article is to evaluate the innovation potential of the dual-phase steel HCT600X...
Unlocking Industry Potential: The Evolution and Impact of Digital Twins
Laura Lachvajderová, Martin Trebuňa, Jaroslava Kádárová
Acta Mechanica Slovaca 2024, 28(1):46-51 | DOI: 10.21496/ams.2024.009
Digital twins have emerged as integral components of modern industrial operations, owing to their ability to create virtual replicas of physical assets, processes, or systems. This article thoroughly explores the manifold applications of digital twins within the industry, emphasizing their role in enabling data-driven decision-making. These virtual counterparts facilitate real-time monitoring, analysis, and optimization, thereby enhancing operational efficiency. Additionally, they play a crucial role in predictive maintenance by minimizing downtime and prolonging the lifespan of machinery. By expediting testing and simulation procedures, digital twins...
Evaluation and Comparison of the Mechanical Behaviors of a Middle Ear Prosthesis using the Finite Element Method
Fekih Sidi Mohamed, Khatir Omar, Sahli Abderahmene, Boudjemaa Ismail, Benkhettou Abdelkader
Acta Mechanica Slovaca 2024, 28(1):38-44 | DOI: 10.21496/ams.2024.006
Advancements in audiology and medical engineering have generated growing interest in enhancing titanium implants for middle ear restoration. In our study, we employed a finite element model of the middle ear to assess the behavior of the TORP prosthesis and the stapes under an acoustic pressure of 90 dB across a frequency range of 250 to 8000 Hz. The results were compared to experimental measurements obtained using a Doppler-effect-based laser vibrometer while varying the materials of the prosthesis to evaluate their mechanical impact. A satisfactory correlation between the simulation and experimental measurements validated our model.
Comprehensive Investigation of Solar Water Heater System Performance, Stratification, Charging, and Discharging Efficiency Using TRNSYS Software
Hanane Berrebah, Touhami Baki, Mohamed Tebbal
Acta Mechanica Slovaca 2024, 28(1):26-36 | DOI: 10.21496/ams.2024.005
A study by dynamic simulation using the TRNSYS software was carried out to visualize the performance of a solar water heater with forced circulation for one year. Thermal needs in domestic hot water for an average family of six people living in the city of Oran in Algeria are covered by solar energy by up to 63%. Parameters such as the angle of inclination, the surface of the solar panel, the storage volume, the heat exchanger's surface, and the flow rate of the solar loop have been optimized. An analysis of the temperature stratification inside the balloon was presented, along with the calculation of charging and discharging efficiency. The influence...
Temperature Measurement of NiTinol Spring without Physical Contact
Jaroslav Romančík, Ondrej Majerčák, Marek Vagaš
Acta Mechanica Slovaca 2024, 28(1):22-25 | DOI: 10.21496/ams.2024.003
Currently, scientists from various fields are trying to find new ways of activating devices, considering the renewability of the used resources. The way to this goal can also be the search for the usability of various advanced materials in hitherto unexplored areas of technology. This article delves into the application of a non-contact infrared sensor MLX90614 to track dynamic temperature changes in a nitinol spring. By utilizing a controllable external power source, the material's temperature is manipulated through current modulation. This fluctuation is then captured and logged by a system that includes a microcontroller and a temperature sensor....
Impact of Psychological Stress on the Development of Musculoskeletal Diseases
Denisa Porubčanová, Michaela Balážiková, Peter Darvaši, Lukáš Ďuriš, Ivan Habala, Hana Pačaiová
Acta Mechanica Slovaca 2024, 28(1):14-20 | DOI: 10.21496/ams.2024.014
This article deals with the issue of the incidence of musculoskeletal diseases in Slovakia in the long term and the possible relationship between their occurrence and the presence of psychological stress. According to statistics, these diseases are a long-term problem plaguing employees in various work sectors and age groups. Their occurrence contributes to the long-term incapacity for work of employees or to their work restrictions, which often require the reassignment of the affected employee to another job or even his or her complete exclusion from employment. This has a negative impact not only on the health of the employee, but also on the operation...
Impact of using FGM Materials for Improving the Efficiency of an Internal Combustion Engine
Maamar Mouheb, Ahmed Fellah, Mohamed Amine Khorchef, Mohamed Reda Larbaoui, Khadidja Boualem
Acta Mechanica Slovaca 2024, 28(1):6-13 | DOI: 10.21496/ams.2024.004
The biggest problem facing internal combustion engine is the decrease of energy efficiency due to thermal losses, which causes an increase in fuel consumption and operating cost, as well as a large amount of burned gas released with major environmental problems resulting. In this context, we will focus in this work about improving the efficiency to minimize all these problems, for this we propose to minimize thermal losses through the use of FGM materials. In this context, a steady state heat conduction analysis of functionally graded cylinder is conducted to present the advantages of using of functionally graded materials over the metallic materials...