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Found 6427 publications

Nonlinear kinematic impacts on nanofluid flow across rough surface with numerical simulation

Dil Nawaz Khan None Hashim Assmaa Abd-Elmonem Hijaz Ahmad Maimoona Karim Abbas Khan Muhammad Zubair Mawadda E.E. Abulhassan Adnan Khan

Publication Name: Scientific Reports

Publication Date: 2025-12-01

Volume: 15

Issue: 1

Page Range: Unknown

Description:

The current study demonstrates the intricate thermo-solutal transportation features of a nanofluid experiencing non-linear kinematics as it flows across a rough porous stretched interface. Previous work has typically been limited to smooth geometries, narrow parameter ranges, and few physical intuitions. However, this paper extends the analysis to include surface roughness, porosity effect, nonlinear stretching and essential physical phenomena like effect of magnetic field, Brownian motion special case thermophoresis effect and variable suction/injection. The resulting extension does not only reproduce realistic flow cases, but reveals extremely sensitive solution behaviors that have been completely untouched in the literature. Using scaling transformation approach, the governing non-linear partial differential equations (PDEs) for the transport of momentum, energy, and solutal in the transformed independent variables are translated into a set of coupled ordinary differential equations (ODEs). Numerical simulation of the above transport equations with ten dimensionless parameters is done using the MATLAB BVP4C (built in solver) approach, which ensures computational stability and high precision across broad parametric domains. Additionally, using an expanded parameter domain revealed previously unknown solution properties. For instance, as the thermophoretic limitation raised, the species concentration rose by 5% and fell by 12%. Additionally, sensitivity was demonstrated by the velocity profiles shifting by 20% in response to a small variation in the slip parameter. Finding the limits at which qualitatively reactions to system modifications and other non-physical solutions arise from the qualitative responses is notably innovative. Such findings will propel the development of more efficient coatings and temperature control techniques, offering helpful advice to greatly improve transportation effectiveness in actual nanofluid applications.

Open Access: Yes

DOI: 10.1038/s41598-025-27743-x

Computational fluid flow simulation on body fitted mesh geometry with IBM cell broadband engine architecture

Sándor Kocsárdi Zoltán Nagy András Kiss Árpád Csík

Publication Name: Ecctd 2009 European Conference on Circuit Theory and Design Conference Program

Publication Date: 2009-12-10

Volume: Unknown

Issue: Unknown

Page Range: 827-830

Description:

The solutions of partial differential equations (PDEs) play a key role in today's real world simulations. Computational Fluid Dynamics (CFD) is an important part of this area, which involves the problem of gas or fluid flow over different obstacles, e.g., air flow around vehicles, buildings, or the flow of water in the oceans. In engineering applications the temporal evolution of non-ideal, compressible fluids is quite often modeled by the system of Navier-Stokes equations. They are a coupled set of nonlinear hyperbolic partial differential equations and form a relatively simple, yet efficient model of compressible fluid dynamics. In the paper the implementation of a CFD on Body Fitted Mesh geometry on the Cell Broadband Engine is described. An arbitrary surface can be more easily simulated on body fitted mesh than on rectangular computation domain. ©2009 IEEE.

Open Access: Yes

DOI: 10.1109/ECCTD.2009.5275111

Modernization of modern buildings - Case study on the main building of Széchenyi István University in Gyo′r

T. Horváth

Publication Name: Pollack Periodica

Publication Date: 2009-12-01

Volume: 4

Issue: 3

Page Range: 67-78

Description:

This paper presents a case study on a building, which was designed in the influence of the New Brutalism in the 1970s. At first the origin, the concept and the values of the building are revealed, then several experts' opinion are summarized about its problems emphasizing the necessity of the frontal modernization. From the description of the designed modernization it is visible how the house will be able to fulfill the recent functional and energetic requirements. © 2009 Akadémiai Kiadó.

Open Access: Yes

DOI: 10.1556/Pollack.4.2009.3.6

Fatigue damage analysis of pavements under autonomous truck tire passes

Richárd Nagy Mohammad Fahad

Publication Name: Pollack Periodica

Publication Date: 2022-12-31

Volume: 17

Issue: 3

Page Range: 59-64

Description:

Two different tire configurations consisting of a dual tire and a super single wide tire having different range and distribution of contact pressures have been analyzed. Along with the effect of speed on development of pavement damage at speeds of 5, 50 and 80 km h-1 under zero and uniform wander modes. Results show that at super slow speeds of 5 km h-1, at dual wheel moving at zero wander mode, decrease in fatigue life of the pavement is 3.5 years, which is 1.45 times more than the dual wheel moving at uniform wander and 3.4 times more than wide tire moving at uniform wander mode. The difference between fatigue damage at different lateral wander modes is prominent at speeds greater than 50 km h-1. A wide tire performs better than the dual wheel under zero wander configurations.

Open Access: Yes

DOI: 10.1556/606.2022.00588

Investigation of Silicone Contamination in Tribometer Experiments Using FT-IR and XPS Technology †

Dominika Pintér Márkó Kovács

Publication Name: Engineering Proceedings

Publication Date: 2025-01-01

Volume: 113

Issue: 1

Page Range: Unknown

Description:

During tribometer experiments, the condition of the applied lubricants plays a crucial role in determining friction and wear properties. Oil degradation can significantly influence measurement outcomes, making it essential to understand the chemical changes that may occur during tribometric experiments. The objective of this study is to systematically investigate the source of silicone contamination and its temperature dependence. Tribometer experiments were conducted at 40, 60, 80, 100, and 120 °C, followed by FT-IR spectroscopy to analyze the lubricant after each measurement. Additionally, wear scars were examined using X-ray photoelectron spectroscopy to determine the presence of silicone within the surface layers. To assess potential alternative contamination sources, a single-drop system was employed, which excludes tubing, thereby providing a controlled environment to verify the origin of the silicone peaks. The results of this study are expected to enhance the reliability of tribometer measurements by identifying contamination sources and optimizing the experimental setup.

Open Access: Yes

DOI: 10.3390/engproc2025113069

Driver Focused Comparison of Field Oriented Control and Direct Torque Control using MATLAB Simulink Simulations

Istvan Szalay Tamás Horváth Denes Fodor

Publication Name: Edpe 2025 37th International Conference on Electrical Drives and Power Electronics and 12th Joint Croatia Slovakia Conference

Publication Date: 2025-01-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

This paper presents a comparison of two widely used motor control strategies namely field oriented control (FOC) and direct torque control (DTC). They both have their advantages and disadvantages that make them a suitable choice for use in a vehicle drive system. This paper compares these two implemented in a MATLAB Simulink simulation using an automotive Permanent Magnet Synchronous Motor (PMSM). The motor and test parameters are chosen to be realistic from a human driver point-ofview. Simulation results are analyzed to highlight the differences between the two strategies and identify cases where one outperforms the other. In conclusion, the paper shows the effects of the differences and the general characteristics of the simulation results in a realistic case on a human driver as the user of the PMSM in an automotive drive. The paper contributes valuable insight in the classic comparison of these two strategies for automotive use.

Open Access: Yes

DOI: 10.1109/EDPE66853.2025.11224164

Numerical analysis of a 2D vector hysteresis measurement system

Miklós Kuczmann

Publication Name: Pollack Periodica

Publication Date: 2007-04-01

Volume: 2

Issue: 1

Page Range: 17-26

Description:

This paper deals with the numerical analysis of a vector hysteresis measurement system, which is under construction in the laboratory. The aim is to build up a single sheet tester with round shaped specimen. The goal of simulations is to find out the main features of the measurement system. The 3D finite element method (FEM) with tetrahedral mesh developed in the laboratory has been applied for investigations of the nonlinear eddy current field problem. The characteristic of the magnetic material has been taken into account by the isotropic vector Preisach model. The nonlinearity has been handled by the polarization method and the nonlinear system of equations has been solved by the fixed-point technique. The first results are presented in this work. © 2007 Akadémiai Kiadó.

Open Access: Yes

DOI: 10.1556/Pollack.2.2007.1.2

Switch-level test calculation for CMOS circuits

Jozsef Sziray

Publication Name: Proceedings International Workshop on Microprocessor Test and Verification

Publication Date: 2009-12-01

Volume: Unknown

Issue: Unknown

Page Range: 41-48

Description:

The paper presents a test calculation principle which serves for producing tests of switch-level logic faults in CMOS digital circuits. The considered fault model includes stuck-at-0/1 logic faults on the connecting control lines, as well as switch faults in the transistors. Both single and multiple faults are included. The transistor faults manifest themselves in stuck open (open circuit) and stuck short (short circuit) behavior. In this paper only combinational logic is taken into consideration. The computations are performed at the transistor level directly, i. e., by using the original transistor schematic solely, without any logic conversion. The calculation principle is comparatively simple. It is based only on successive line-value justification, and it yields an opportunity to be realized by an efficient computer program. © 2009 IEEE.

Open Access: Yes

DOI: 10.1109/MTV.2009.24

Comparative Analysis of Discrete-Time and Precedence-Based MILP Formulations for Sustainable Scheduling in Furniture Manufacturing

Botond Bertok Károly Kalauz Márton Frits

Publication Name: Chemical Engineering Transactions

Publication Date: 2025-01-01

Volume: 121

Issue: Unknown

Page Range: 151-156

Description:

Efficient production scheduling plays a pivotal role in enhancing productivity and reducing energy consumption in mass manufacturing environments. This study presents a comparative evaluation of two mixed-integer linear programming (MILP) formulations - Discrete-Time Process Network Synthesis (PNS) and Precedence-Based Time-Constrained Process Network Synthesis (TCPNS) - for optimizing production scheduling in furniture manufacturing. Both approaches are grounded in the P-graph framework, which excels at representing complex, flexible process recipes commonly found in large-scale production systems. The TCPNS model, with its precedence-based structure, offers high-resolution scheduling capabilities and accurately manages complex changeover constraints. It enables the computation of exact start times and resource allocations, leading to highly optimized schedules. However, this precision comes with increased computational demand, which can become impractical for large-scale instances. Conversely, the PNS approach discretizes the planning horizon into time slots, significantly reducing model size and complexity. While this may result in less granular schedules, the formulation allows for faster solution times and easier integration of combinatorial simplifications, making it a practical alternative for real-time applications. The research also explores automated model generation techniques for both formulations, highlighting multi-resolution capabilities in the discrete-time approach that allow flexible trade-offs between accuracy and computational effort. A real-life case study from the furniture manufacturing sector is used to benchmark the two optimization strategies. The results demonstrate the practical implications of each method in terms of schedule precision, computational performance, and energy-aware utilization, i.e., if minute-to-minute scheduling is sufficient instead of milliseconds, then traditional PNS algorithms can offer the same sustainable solution with 10,000 times faster computation.

Open Access: Yes

DOI: 10.3303/CET25121026