TY  - JOUR
AU  - Lelkes, János
AU  - Kalmár-Nagy, Tamás
TI  - Analysis of a piecewise linear aeroelastic system with and without tuned vibration absorber
JF  - NONLINEAR DYNAMICS
J2  - NONLINEAR DYNAM
VL  - 103
PY  - 2021
IS  - 4
SP  - 2997
EP  - 3018
PG  - 22
SN  - 0924-090X
DO  - 10.1007/s11071-020-05725-0
UR  - https://m2.mtmt.hu/api/publication/31379698
ID  - 31379698
N1  - Cited By :3            
            Export Date: 5 July 2022            
            CODEN: NODYE            
            Correspondence Address: Lelkes, J.; Department of Fluid Mechanics, Hungary; email: lelkes@ara.bme.hu            
            Funding details: Science Foundation Ireland, SFI, 07/CE/1142            
            Funding text 1: This research was funded by Science Foundation Ireland under the Research Frontiers program. The presentation was funded by Grant 07/CE/1142, Centre for Next Generation Localisation (CNGL).
AB  - The dynamics of a two-degrees-of-freedom (pitch–plunge) aeroelastic system is investigated. The aerodynamic force is modeled as a piecewise linear function of the effective angle of attack. Conditions for admissible (existing) and virtual equilibria are determined. The stability and bifurcations of equilibria are analyzed. We find saddle-node, border collision and rapid bifurcations. The analysis shows that the pitch–plunge model with a simple piecewise linear approximation of the aerodynamic force can reproduce the transition from divergence to the complex aeroelastic phenomenon of stall flutter. A linear tuned vibration absorber is applied to increase stall flutter wind speed and eliminate limit cycle oscillations. The effect of the absorber parameters on the stability of equilibria is investigated using the Liénard–Chipart criterion. We find that with the vibration absorber the onset of the rapid bifurcation can be shifted to higher wind speed or the oscillations can be eliminated altogether.
LA  - English
DB  - MTMT
ER  - 

TY  - JOUR
AU  - Kalmár-Nagy, Tamás
AU  - Csikja, Rudolf
AU  - Elgohary, T
TI  - Nonlinear analysis of a 2-DOF piecewise linear aeroelastic system
JF  - NONLINEAR DYNAMICS
J2  - NONLINEAR DYNAM
VL  - 85
PY  - 2016
IS  - 2
SP  - 739
EP  - 750
PG  - 12
SN  - 0924-090X
DO  - 10.1007/s11071-016-2719-z
UR  - https://m2.mtmt.hu/api/publication/2994999
ID  - 2994999
LA  - English
DB  - MTMT
ER  - 

TY  - JOUR
AU  - Kalmár-Nagy, Tamás
AU  - Ilinca, Stanciulescu
TI  - Can complex systems really be simulated?
JF  - APPLIED MATHEMATICS AND COMPUTATION
J2  - APPL MATH COMPUT
VL  - 227
PY  - 2014
SP  - 199
EP  - 211
PG  - 13
SN  - 0096-3003
DO  - 10.1016/j.amc.2013.11.037
UR  - https://m2.mtmt.hu/api/publication/2834773
ID  - 2834773
AB  - The simulation of complex systems is important in many fields of science and in real-world applications. Such systems are composed of many interacting subsystems. There might exist different software packages for simulating the individual subsystems and co-simulation refers to the simultaneous execution of multiple interacting subsystem simulators. Simulation or co-simulation, if not designed properly, can return misleading numerical solutions (unstable numerical solutions for what is in fact a stable system or vice versa). To understand the cause of these numerical artifacts, we first propose a simple mathematical model for co-simulation, and then construct stability charts. These charts shed light on transitions between stable and unstable behavior in co-simulation. Our goal is to understand the stability properties of the simulated and co-simulated representation of the continuous system. We will achieve this goal by expressing the trace and determinant of the discretized system in terms of the trace and determinant of the continuous system to establish stability criteria.
LA  - English
DB  - MTMT
ER  -