László Könözsy

Dr. László Könözsy


Research Focus & Metrics

Academic Career Length

19Years (2008-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 August 2015 in Computer Methods in Applied Mechanics and Engineering
Verified
Journal Article
Closed access
PTPanagiotis Tsoutsanis
Panagiotis Tsoutsanis
IKIoannis W. Kokkinakis
Ioannis W. Kokkinakis
László KönözsyLászló Könözsy
László Könözsy
Dimitris DrikakisDimitris Drikakis
Dimitris Drikakis
RWRobin J.R. Williams
Robin J.R. Williams
DYDavid L. Youngs
David L. Youngs

1 July 2018 in Aerospace Science and Technology
Verified
Journal Article
Open access
MRMauro Righi
Mauro Righi
VPVassilios Pachidis
Vassilios Pachidis
László KönözsyLászló Könözsy
László Könözsy
LPLucas Pawsey
Lucas Pawsey

1 September 2016 in Journal of Loss Prevention in the Process Industries
Verified
Journal Article
Open access
ESEdmilson P. Silva
Edmilson P. Silva
MNMarcio Nele
Marcio Nele
PMPaulo F. Frutuoso e Melo
Paulo F. Frutuoso e Melo
László KönözsyLászló Könözsy
László Könözsy
This paper focuses on the analysis of the possibility of domino effect in underground parallel pipelines relying on historical accident data and pipeline crater models. An underground pipeline can be considered as safe following an accident with an adjacent gas or liquefied pipeline when it remains outside the ground crater generated. In order to prevent the domino effect in these cases, the design of parallel pipelines has to consider adequate pipeline separations based on the crater width, which is one of the widely used methods in engineering applications. The objective of this work is the analysis of underground petroleum product pipelines ruptures with the formation of a ground crater as well as the evaluation of possible domino effects in these cases. A detailed literature survey has been carried out to review existing crater models along with a historical analysis of past accidents. A FORTRAN code has been implemented to assess the performance of the Gasunie, the Batelle and the Advantica crater models. In addition to this, a novel Accident-Based crater model has been presented, which allows the prediction of the crater width as a function of the relevant design pipeline parameters as well as the soil density. Modifications have also been made to the Batelle and Accident-Based models in order to overcome the underestimation of the crater width. The calculated crater widths have been compared with real accident data and the performance evaluation showed that the proposed Accident-Based model has a better performance compared to other models studied in this work. The analysis of forty-eight past accidents indicated a major potential of underground parallel pipelines domino effect which is proven by two real cases taken from the literature. Relying on the investigated accidents, the crater width was smaller than or equal to 20 m in most cases indicating that the definition of underground pipeline separations at around 10 m would be sufficient to ensure a small probability of the domino effect

6 April 2016 in Microfluidics and Nanofluidics
Verified
Journal Article
Open access
PDF file
Tom-Robin TeschnerTom-Robin Teschner
Tom-Robin Teschner
László KönözsyLászló Könözsy
László Könözsy
Karl JenkinsKarl Jenkins
Karl Jenkins
This work focuses on the review of particle-based multiscale and hybrid methods that have surfaced in the field of fluid mechanics over the last 20 years. We consider five established particle methods: molecular dynamics, direct simulation Monte Carlo, lattice Boltzmann method, dissipative particle dynamics and smoothed-particle hydrodynamics. A general description is given on each particle method in conjunction with multiscale and hybrid applications. An analysis on the length scale separation revealed that current multiscale methods only bridge across scales which are of the order of \({\mathcal {O}}(10^2) {-} {\mathcal {O}}(10^3)\) and that further work on complex geometries and parallel code optimisation is needed to increase the separation. Similarities between methods are highlighted and combinations discussed. Advantages, disadvantages and applications of each particle method have been tabulated as a reference.

11 December 2017 in Aerospace
Verified
Journal Article
Open access
PDF file
MRMoutassem El Rafei
Moutassem El Rafei
László KönözsyLászló Könözsy
László Könözsy
Zeeshan RanaZeeshan Rana
Zeeshan Rana
The quantitative measure of dissipative properties of different numerical schemes is crucial to computational methods in the field of aerospace applications. Therefore, the objective of the present study is to examine the resolving power of Monotonic Upwind Scheme for Conservation Laws (MUSCL) scheme with three different slope limiters: one second-order and two third-order used within the framework of Implicit Large Eddy Simulations (ILES). The performance of the dynamic Smagorinsky subgrid-scale model used in the classical Large Eddy Simulation (LES) approach is examined. The assessment of these schemes is of significant importance to understand the numerical dissipation that could affect the accuracy of the numerical solution. A modified equation analysis has been employed to the convective term of the fully-compressible Navier–Stokes equations to formulate an analytical expression of truncation error for the second-order upwind scheme. The contribution of second-order partial derivatives in the expression of truncation error showed that the effect of this numerical error could not be neglected compared to the total kinetic energy dissipation rate. Transitions from laminar to turbulent flow are visualized considering the inviscid Taylor–Green Vortex (TGV) test-case. The evolution in time of volumetrically-averaged kinetic energy and kinetic energy dissipation rate have been monitored for all numerical schemes and all grid levels. The dissipation mechanism has been compared to Direct Numerical Simulation (DNS) data found in the literature at different Reynolds numbers. We found that the resolving power and the symmetry breaking property are enhanced with finer grid resolutions. The production of vorticity has been observed in terms of enstrophy and effective viscosity. The instantaneous kinetic energy spectrum has been computed using a three-dimensional Fast Fourier Transform (FFT). All combinations of numerical methods produce a k − 4 spectrum at t * = 4 , and near the dissipation peak, all methods were capable of predicting the k − 5 / 3 slope accurately when refining the mesh.