H. Szűcs

57497395800

Publications - 10

Numerical study to investigate the effect of sample size sensitivity on porous materials with respect to different geometrical parameters

H. Szűcs

Publication Name: Results in Materials

Publication Date: 2024-06-01

Volume: 22

Issue: Unknown

Page Range: Unknown

Description:

Porous materials play a crucial role in various industrial applications, where precise determination of geometric parameters like dynamic tortuosity, as well as viscous and thermal characteristic lengths, is essential for optimizing acoustical performance. Up to this point, there has been no published size sensitivity test that recommends the ideal sample size for analyzing these parameters in an industrial environment. The present article analyzes different reconstructed porous material samples using conventional CFD and coupled FEA-CFD simulations and suggests optimal sample size and specific simulation setup optimized for industrial purposes, which grant high accuracy and reasonable computational cost. The present paper analyzed several samples, which were reconstructed by micro-CT and analyzed in Star-CCM+ simulation environment. It was found that the optimal sample size (1.5×1.5×1.5 mm or 2.5×2.5×2.5 mm) is different for specific average pore sizes. It was proven through various numerical simulations based on reconstructed porous material samples that running only one coupled CFD-FEM simulation is satisfactory to directly determine all investigated parameters. It was demonstrated that the computationally demanding numerical model could be simplified in specific cases using a rigid body and highlight the limitations.

Open Access: Yes

DOI: 10.1016/j.rinma.2024.100554

Numerical study to investigate the thermal characteristic length with coupled CFD-FEM simulations

H. Szűcs

Publication Name: International Journal of Heat and Fluid Flow

Publication Date: 2024-04-01

Volume: 106

Issue: Unknown

Page Range: Unknown

Description:

This paper introduces a new technique for directly calculating the thermal characteristic length (Λ′) of porous materials, addressing a critical parameter required for accurate acoustic simulations during vehicle development. The proposed method offers improved practicality over existing approaches. The research seeks to overcome the limitations of current methods, proposing a coupled CFD-FEA approach within a fluid–structure interaction (FSI) simulation framework. By incorporating both fluid temperature and the fundamental definition of characteristic length, this formulation enables the direct calculation of Λ′. The validity of the method is established through specific tests conducted on ten reconstructed material samples. The proposed approach outperforms measurement techniques and established formulas, offering enhanced accuracy while overcoming the limitations of experimental repeatability. The study demonstrates the universal nature of characteristic curves across various flow regimes, ensuring consistent parameter determination under different flow conditions and sample sizes. Additionally, the research highlights the significant influence of structure deformation, regardless of flow regime, sample size, and flow direction. This paper advances the comprehension of characteristic parameters across diverse conditions by presenting a new method that enhances practicality, accuracy, and applicability to vehicle acoustic simulations.

Open Access: Yes

DOI: 10.1016/j.ijheatfluidflow.2024.109312

The Environmental Sustainability Potential of Autonomous Vehicles: An Overview

H. Szűcs Jozefin Szűcs

Publication Name: Periodica Polytechnica Transportation Engineering

Publication Date: 2024-01-01

Volume: 52

Issue: 3

Page Range: 246-256

Description:

The optimization of transportation systems and the integration of autonomous vehicles (AV) are significantly transforming urban mobility and exerting outstanding effects from an environmental perspective. This article examines the possibilities of autonomous vehicles in reducing traffic congestion, emissions, and energy consumption. The optimized driving style of AVs, dynamic route planning, and enhanced intersection systems have a profound impact on emission reduction. The article also delves into current development trends and challenges, encompassing advancements in AV sensing technologies, traffic safety, and cybersecurity. These findings collectively suggest that the deployment of autonomous vehicles brings substantial benefits to sustainable urban mobility; however, further development is necessary to support the widespread adoption of AVs and strengthen societal trust.

Open Access: Yes

DOI: 10.3311/pptr.23933

Exploring the impact of compressibility on reconstructed porous materials: A numerical study

H. Szűcs

Publication Name: Journal of Engineering Research Kuwait

Publication Date: 2025-09-01

Volume: 13

Issue: 3

Page Range: 1987-2003

Description:

This study underscores fluid density's significance in CFD simulations for porous materials, addressing its impact on accuracy and computational efficiency. The paper proposes a tailored form of Navier-Stokes equations that accounts for fluid density's influence on CFD analyses of porous materials in industrial contexts, including cases where the solid phase is deformable. Numerical analyses demonstrate fluid density's significance (ρ≠constant) and explore the importance of the energy equation in governing equations. The energy equation is essential in setting up the governing equations, as it calculates thermal characteristic length based on cell temperatures. By examining various porous material samples, the study suggests a streamlined approach: employing a single coupled CFD-FEM simulation to directly determine each geometrical parameter. Additionally, the study investigates the capability to accurately simulate turbulent fluid motion at the pore scale and analyze the flow field characterization within porous media. Computational cost analyses underscore the advantages of coupled simulations, establishing their profitability over separate parameter-specific simulations.

Open Access: Yes

DOI: 10.1016/j.jer.2024.07.018

Numerical study to investigate the viscous characteristic length on reconstructed porous media

H. Szűcs

Publication Name: Alexandria Engineering Journal

Publication Date: 2023-03-01

Volume: 66

Issue: Unknown

Page Range: 269-286

Description:

Until now, no general numerical method has been published for characterizing the viscous characteristic length, although there is a high demand to assist whole vehicle development with accurate geometric parameters. A new formula was proposed to determine the viscous characteristic length (Λ) directly based on the viscous dissipation work, which was combined with the general definition of the characteristic length. This new expression facilitated significantly faster convergence than the known formula (Johnson) for inviscid fluids by representing viscous fluids through the material sample. The complete CFD simulation procedure was introduced based on the solution of Navier-Stokes equations. The novel expression is capable of any homogeneous material samples assuming that high-resolution reconstruction can be carried out, compared to Johnson's formula, which is limited to idealized cases. Good agreement between simulation and measurement results was found by applying fluid velocity instead of frequency. It was found that viscous losses dominate not only inside the pore connections but also in other regions, and the Reynolds number must be limited to the laminar regime. On that basis, the implemented model has more advantages against measurements and Johnson's formula, like the repeatability as well as ensuring analyses under steady-state and real conditions.

Open Access: Yes

DOI: 10.1016/j.aej.2022.11.022

A Comprehensive Review of the Simulation Methods for Analysis at the Pore-scale

Balázs Vehovszky H. Szűcs Brian Sanders

Publication Name: Periodica Polytechnica Transportation Engineering

Publication Date: 2023-01-01

Volume: 51

Issue: 2

Page Range: 105-116

Description:

Fluid flow through porous material is relevant in different fields of engineering, such as in engine and vehicle development, and can be supported through CFD simulation. Numerical simulations at the pore-scale can be used to replace or reduce expensive laboratory measurements. These methods offer a valuable opportunity to connect the pore-scale properties of the porous material with displacement processes on the continuum-scale. Furthermore, they allow researchers to specify crucial flow properties, e.g., capillary pressure, which are crucial for REV-scale research. Three main methods, direct numerical, pore network modeling, and hybrid approaches, are widely used in order to analyze the pore-scale mechanics of fluid flow behavior through porous materials with CFD simulations. The present comprehensive review demonstrates and highlights the significant advantages, disadvantages, and critical challenges in the pore-scale fluid flow simulations. The main challenges include the characterization of material properties, and up-scaling process from pore to continuum or field-scale.

Open Access: Yes

DOI: 10.3311/PPtr.18452

Reconstruction of 3D Porous Geometry for Coupled FEM-CFD Simulation

H. Szűcs

Publication Name: Periodica Polytechnica Mechanical Engineering

Publication Date: 2022-01-01

Volume: 66

Issue: 2

Page Range: 129-136

Description:

Porous materials can be found in numerous areas of life (e. g., applied science, material science), however, the simulation of the fluid flow and transport phenomena through porous media is a significant challenge nowadays. Numerical simulations can help to analyze and understand physical processes and different phenomena in the porous structure, as well as to determine certain parameters that are difficult or impossible to measure directly or can only be determined by expensive and time-consuming experiments. The basic condition for the numerical simulations is the 3D geometric model of the porous material sample, which is the input parameter of the simulation. For this reason, geometry reconstruction is highly critical for pore-scale analysis. This paper introduces a complex process for the preparation of the microstructure's geometry in connection with a coupled FEM-CFD two-way fluid-structure interaction simulation. Micro-CT has been successfully applied to reconstruct both the fluid and solid phases of the used porous material.

Open Access: Yes

DOI: 10.3311/PPme.19438

Investigation of Possibilities of λ = 1 Full Load Operation for Gasoline Engines in the Light of Future Emission Regulation

György Szabados H. Szűcs Jozefin Hézer Brian Sanders

Publication Name: Periodica Polytechnica Transportation Engineering

Publication Date: 2022-01-01

Volume: 50

Issue: 2

Page Range: 111-127

Description:

To date, huge amounts of money have been invested in the development of internal combustion engines to reach the current level of technology. High specific power and good thermal efficiency have been achieved, thanks to which, internal combustion engines are now widely used. However, the driving force behind the developments is no longer the high performance, but the compliance with strict emission standards. Future emissions regulation, namely Euro 7, will be challenging for engine and vehicle manufacturers. One possible technical solution may be to use a stoichiometric air-fuel mixture on the entire engine map to meet the requirements of the Euro 7 emission standard. This article analyzes the change in Euro regulations in the light of Euro 7, as well as the theoretical background of the λ = 1 operation. Several technical possibilities to achieve the stoichiometric ratio, such as e.g. water injection or variable compression ratio are presented.

Open Access: Yes

DOI: 10.3311/PPtr.17433

Road Safety Analysis of Autonomous Vehicles

H. Szűcs Jozefin Hézer

Publication Name: Periodica Polytechnica Transportation Engineering

Publication Date: 2022-01-01

Volume: 50

Issue: 4

Page Range: 426-434

Description:

For the widespread use of Autonomous Vehicles (AVs), a huge number of challenges must be solved by vehicle manufacturers, in contrast they do have significant potential to increase road safety in both passenger and freight transport. In addition to reducing road traffic accidents and traffic jams, AVs also offer a major opportunity to reduce pollutant emissions and CO2 emissions from environmental point of view. In order to implement accident-free traffic, also called Vision Zero, it is essential to examine the safety and reliability of AVs. This article analyzes road traffic accident data and the potential safety benefits of AVs. Furthermore, the paper also sets the safety of the conventional vehicles against AVs and examines the type, location, causes, and dynamics of the accidents. The article also provides an overview over the current development trends and challenges, such as the risk of cyber-attacks, the necessary improvements in sensing technologies, and the not insignificant moral issue of AVs.

Open Access: Yes

DOI: 10.3311/PPtr.19605

Possibilities of porous-structure representation – an overview

Balázs Vehovszky H. Szűcs

Publication Name: Acta Technica Jaurinensis

Publication Date: 2021-11-24

Volume: 14

Issue: 4

Page Range: 553-576

Description:

Porous media can be found in all areas of scientific life, such as medicine, civil engineering, material science, fluid dynamics. Computing has achieved high efficiency and computational capacity – so far. However, three-dimensional Computational Fluid Dynamics (CFD) simulations of microstructure remain significant challenges. Pore-scale simulations can help understand the physical processes and determine macroscopic parameters such as the high-frequency limit of dynamic tortuosity, viscous, and thermal characteristic lengths. Independent of whether the computational problem is two or three-dimensional, the geometry as input parameter must be prepared. For this reason, geometry representation methods play a crucial role in the analysis at the pore-scale, especially in numerical simulations. In this article, an insight into microstructures’ visualization capabilities is provided essentially for CFD simulations.

Open Access: Yes

DOI: 10.14513/actatechjaur.00591