Temat: dynamics simulation - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Influence of the tire relaxation on the simulation results of the vehicle lateral dynamics in aspect of the vehicle driving safety
Autorzy:: Luty, W.
Powiązania:: https://bibliotekanauki.pl/articles/244449.pdf
Data publikacji:: 2015
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: tire relaxation
vehicle safety
lateral dynamics
vehicle dynamics simulation
vehicle driving safety
Opis:: Selected experimental research results of truck tire in steady-state side cornering and transient cornering conditions are presented in this paper. Experimental research results of the tire have been used in simulation research of medium duty truck in nonlinear driving conditions. The paper presents the structure of the vehicle dynamics model and a description of applied tire-road interaction model. Simulation research of the vehicle lateral dynamics has been performed in two variants: without and with the model of tire relaxation. During research, the tire relaxation length has been also changed. The steering wheel angle changes were forced as continuous sinusoidal excitation signal with a constant amplitude and with continuously increasing frequency. There have been analysed basic physical quantities characterizing the vehicle lateral dynamics connected with the vehicle active safety, especially including body yaw velocity and lateral acceleration in the centre of the truck body mass. An analysis of research results have been performed in the time and frequency domain. Time courses of analysed physical quantities and their frequency spectrum, obtained for tire-road interaction model without and with the tire relaxation (with different values of relaxation length) have been compared. Based on the simulation research results there have been considered the influence of tire relaxation on the vehicle performance. There have been shown that the tire relaxation can significantly change courses of observed physical quantities connected with vehicle lateral dynamics connected with vehicle driving safety.
Źródło:: Journal of KONES; 2015, 22, 1; 185-192
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Simulational study of a hydraulicly driven parallel manipulator control system
Autorzy:: Frączek, J.
Wojtyra, M.
Dayliakos, I.
Papadopoulos, E.
Powiązania:: https://bibliotekanauki.pl/articles/243340.pdf
Data publikacji:: 2008
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: robotics
control
dynamics
simulation
parallel manipulators
inverse dynamics models
Opis:: A simulational model of 6 dof Stewart platform type parallel manipulator is presented. The manipulator is driven by electrohydraulic actuators. The developed control scheme employs the dynamic and hydraulic model of the system. The manipulator model consists of the rigid body equations of motion and the hydraulic dynamics of the main elements. Friction is included in the model. Two well-known software packages, one designed to perform control system simulation and the other dedicated to multibody simulation, are simultaneously used to conduct the study. The aim of the study is to check if it is the impact of dynamics model accuracy on the quality of control process. The simplifications of the model and the problems with finding accurate values of its parameters (especially friction parameters) are considered. The study helps to predict the possible results of inaccurate determination of the crucial model parameters. The simulation results show, that inverse dynamics model simplifications consisting in neglecting the mass of actuators have relatively little influence on the control quality. The effects of actuators masses neglecting can be reduced by appropriate changes in the modelled mass of the platform. The study shows that friction effects should be introduced to the inverse dynamics model and the friction parameters should be identified with possibly big accuracy. The parameters describing stiction-friction transition effects are the crucial ones.
Źródło:: Journal of KONES; 2008, 15, 1; 51-67
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Ways of uneven road surface modelling used in the vehicle dynamics analysis
Autorzy:: Tengler, S.
Harlecki, A.
Powiązania:: https://bibliotekanauki.pl/articles/247939.pdf
Data publikacji:: 2012
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: vehicle dynamics
uneven road surface modelling
computer simulation
Opis:: An important issue, which should be taken into account while analyzing the dynamics of vehicles moving along an uneven road surface, is the proper representation of its real shape. Two mathematical models of the road surface - continuous and discrete were considered in the method presented in this paper. These models were used in the computer simulations of dynamics of a special vehicle with a high gravity centre, which moved along an uneven road surface. The simulations were carried out using the worked out program package, in which four main modules could be differentiated such as: preprocessor, solver, postprocessor and 3D animation. This package was implemented combined with the Blender graphics environment – in authors’ opinion it is an innovative approach. Owing to this models of uneven road surface (theoretically of any shapes) can be built and they are input data for both the solver and animation modules. Additionally, the Blender tool can be used to prepare 3D objects, which are used in the animation process of the moving model of a vehicle. According to the authors', developed program package developed on the basis of the mathematical models for the analyzed vehicle and road surface can be interesting for engineers designing special vehicles. By performing different types of the computer simulations, the engineers can improve the vehicle being built and reduce cost of its road test.
Źródło:: Journal of KONES; 2012, 19, 1; 441-451
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Application of the finite element methods in long-term simulation of the multi physics systems with large transient response differences
Autorzy:: Wittbrodt, E.
Kahsin, M.
Powiązania:: https://bibliotekanauki.pl/articles/243299.pdf
Data publikacji:: 2008
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: dynamics
thermo elasticity
FEM
MBS
simulation
multi-physics systems
Opis:: Application of the Finite Element Method (FEM) and the Multibody Dynamics Method (MBS) allows analyzing of complex physical systems. Complexity of the system could be related both to the geometry and the physical description of phenomenon. MBS is the excellent tool for analyzing statics or dynamics of the mechanical systems. MBS permits tracking of Multi Body System transient response for the long-term simulations and application of any arbitrary set of mechanical forcing functions. However, this method does not allow observing state of the continuum systems. Besides, applying forcing functions other than mechanical ones (i.e. general forces or displacements) is troublesome in MBS. In case of FEM most of algorithms encounter continuity conditions across the element boundaries , and thanks to this FEMis one of the most suitable calculation method for continua multi-physics systems (i.e. thermo-structural, electro-thermo-structural, magneto-thermo-structural, MEMS, etc.). Common problem with FEM is that there are major calculation difficulties when long-term simulation results are required and/or large relative motions are present in the system. Drawbacks of FEM and MBS could be overcome with use of algorithm based on the modifled Hybrid Finite Element Method presented further in this paper. Traditional Hybrid Finite Element Method model consists of rigid end deformable elements, system matrices derived for all compound elements are calculated concurrently. In this approach both advantages and disadvantages of FEM and MBS are transferred to the model. Proposed modified Hybrid Finite Element Method algorithm exploits two corresponding coupled discrete models, one containing FEM elements and the other MBS only. Both models are coupled by means of forcing functions. Such approach is applicable for the multi-physics systems with large transient response differences.
Źródło:: Journal of KONES; 2008, 15, 1; 227-233
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Jet and droplet breakup modelling approaches
Autorzy:: Kapusta, Ł. J.
Jaworski, P.
Kowalski, J.
Powiązania:: https://bibliotekanauki.pl/articles/245813.pdf
Data publikacji:: 2015
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: spray
modelling
simulation
breakup
injection
CFD
computational fluid dynamics (CFD)
Opis:: Three-dimensional computational fluid dynamics (CFD) plays important role in engines development. The mixture formation in a direct-injection piston engines poses a huge challenge in successful simulations of the engine processes. It is due to the fact that the spray as a two-phase flow complicates the computational process. Moreover, this multiphase flow is not uniform. Three main zones, depending on the distance from the nozzle exit are visible when a liquid is injected. Very dense so called “thick” in a direct vicinity of the injector hole, than “thin” as a result of pri-mary breakup downstream the injector and finally in the certain distance from the injector appears “very thin” region as a result of secondary breakup. It is important to take into account that the liquid phase in various regimes behaves differently and is under influence of different phenomena. The modelling approach needs to take in to consideration all those elements. This paper focuses on presentation of the theory and numerical models for primary and secondary breakup phenomena. The primary breakup is a process that results from a combination of three mechanisms: turbu-lence within liquid phase, implosion of cavitation’s bubbles and aerodynamic forces acting on a liquid jet. Secondary breakup regime occurs mainly due to the aerodynamic interactions between the liquid and the gaseous phase.
Źródło:: Journal of KONES; 2015, 22, 3; 83-90
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Influence of the atmospheric turbulence on the accuracy of the missile targeting
Autorzy:: Kowaleczko, G.
Kaźmierczak, R.
Powiązania:: https://bibliotekanauki.pl/articles/950099.pdf
Data publikacji:: 2017
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: missile dynamics
stochastic turbulence
numerical simulation
dynamika pocisku
symulacja numeryczna
Opis:: The article presents results of simulation of 6-DOF motion for a missile subjected to atmospheric turbulences. Therefore, an applied mathematical model of motion includes description of stochastic turbulences influencing on missile flight. Both models of the motion as well as of turbulences are shortly presented. Model validity was assessed by comparing the calculation results with the data recorded during shooting on the range. Result of series of simulations allows determining the missile sensitivity to this case of disturbances. Exemplary results of simulations are shown. The turbulence model assumes that the wind is dependent on time and space. This assumption is based on the Taylor's "frozen turbulence" hypothesis. The advection velocity of the turbulence is much greater than the velocity scale of the turbulence itself. The velocity has two component. In the article, the first component is omitted and the second is treated as the stochastic process representing atmospheric turbulence. To describe this turbulence Shinozuka's method was applied. Mathematical description of the missile motion, equations of translatory motion, External forces end moments, model of the turbulence are presented in the article.
Źródło:: Journal of KONES; 2017, 24, 1; 211-222
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Simulation method of car motion reconstruction based on ADR/EDR device records
Autorzy:: Guzek, M.
Powiązania:: https://bibliotekanauki.pl/articles/244080.pdf
Data publikacji:: 2009
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: car "blach boxes"
EDR
accident reconstruction
vehicle dynamics
vehicle motion simulation
Opis:: The so-called car "black boxes " — ADR recorders have been available on automotive markets for many years. The task of those devices is to record Information on car motion, driver's behaviour, state of vehicle systems and neighbouring environment. The records are to allow for accident reconstruction. In general, the devices being proposed are a simplified version of devices that have been applied e.g. in aviation for a long time. The problem is how those simplifications may affect the accuracy of reconstructions being performed. The simulation method of this type of research has been presented in this paper. A proceeding diagram, mathematical models of car motion applied in the method, records of ADR devices, an algorithm for processing quantities, recorded in ADR, in order to obtain reconstructed velocities histories and trajectories of car motion have been illustrated. A special attention was paid to a mathematical description of readings of acceleration sensors of ADR devices. An example of the experimental method verification has been presented. Then, three computational examples have been presented that focused on evaluation of influence of a number of quantities, being recorded in the ADR device, deser ibing vehicle motion. It has been indicated that missing Information on some quantities in devices, typical nowadays in automotive sector, may essentially affect the accuracy of car motion reconstruction.
Źródło:: Journal of KONES; 2009, 16, 1; 185-198
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Theoretical and experimental investigation of a ground resonance phenomenon for the ILX-27 UAV helicopter
Autorzy:: Kowaleczko, G.
Gorecki, T.
Powiązania:: https://bibliotekanauki.pl/articles/245785.pdf
Data publikacji:: 2017
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: ground resonance
dynamics of helicopter structure
finite element method
simulation
ground tests
Opis:: Ground resonance is an unbalance of the helicopter main rotor rotation caused by its asymmetry. Whilst the helicopter is in contact with the ground this asymmetry generates a divergent and often destructive oscillations of the helicopter structure. These oscillations are self-excited. This paper present results of both theoretical and experimental investigations of this phenomenon. They were dedicated to the new polish UAV helicopter ILX-27. The theoretical analysis were done with commercial software ANSYS using Finite Element Method. The virtual model of the helicopter model accurately reproduced the geometry of all elements of the helicopter and was easy to modify to simulate various kinds of damages. Calculations were done for the following cases: C1 – the helicopter standing on the ground with zero thrust of the rotor, C2 = C1 + helicopter with additional support of the rotor mast, C3 = C2 + thrust of the rotor equal to the total mass of the helicopter, C4 = C2 + fixing the helicopter to the ground, C5 = C2 + helicopter with additional mass. At the beginning the modal analysis for all cases was done – natural frequencies and modes of the structure were identified. Next, for selected cases, harmonic analysis was performed – the structure of the helicopter was loaded with concentrated harmonic forces. Finally the dynamic analysis gave time courses of blades and the hub center motions in the case of structural damages. All phases of simulations were correlated with ground tests of the helicopter prototype. This allowed to compare results of theoretical investigations. These results also supported tests of the prototype.
Źródło:: Journal of KONES; 2017, 24, 4; 91-98
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: Virtual ship’s roll decay test with the use of CFD technique
Autorzy:: Krata, P.
Jachowski, J.
Powiązania:: https://bibliotekanauki.pl/articles/243570.pdf
Data publikacji:: 2016
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: sea transport
ship stability
roll simulation
roll decay test
computational fluid dynamics
Opis:: Since safety of navigation is related to the stability performance of a ship, the transverse stability is routinely calculated and measured. One of the crucial experimental approach is a roll decay test. Although, an obtained result of the roll decay test carried out on the full-scale ship needs to be compared to a benchmark enabling an estimation of the relevant stability. Nowadays such a benchmark is just based on the simplified GM-based IMO-recommended formula. This research aims at the more sophisticated method of ship’s natural period of roll estimation and thus her stability assessment. The CFD (computational fluid dynamics) technique is applied and the result of the free roll simulation is compared to the solution of a roll equation. The one degree-of-freedom roll equation is applied with regard to the nonlinear ship righting moment and the nonlinear damping moment obtained according to Ikeda’s method. The six degrees-of-freedom simulation of ship’s roll decay test was carried out by the use of FlowVision code utilizing the Reynolds-averaged Navier–Stokes equation with regard to the turbulent flows based on the eddy viscosity concept. The semi-empirical k-ε turbulence model was applied. Thereby, the CFD-based approach allows to get rid of any assumptions regarding the value of the damping coefficient, which is an advantage over the roll equation based approach.
Źródło:: Journal of KONES; 2016, 23, 2; 215-221
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: Simulation of rime icing and its effects on aerodynamic characteristics of an airfoil
Autorzy:: Sznajder, J.
Powiązania:: https://bibliotekanauki.pl/articles/243475.pdf
Data publikacji:: 2018
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: computational fluid dynamics
aerodynamics
two-phase flow
simulation of ice accretion
heat exchange
aircraft engineering
transport
vehicle
Opis:: A mathematical model for simulation of icing dedicated to simulation of ice accretion and its effects on aircraft aerodynamic characteristics in conditions of rime icing is presented. Pure rime icing occurs at lower temperatures than glaze icing and results in higher roughness of the surface of deposited ice. The model accounts for increased surface roughness, in terms of equivalent sand grain roughness, caused by deposited rime ice, which influences generation and dispersion of heat in the boundary layer. Increase of surface roughness is determined by analytical models created upon experimental data obtained in icing wind tunnels. Increased generation of heat is a result of increased tangential stress on the surface and is quantified in the temperature recovery factor determined numerically by a CFD solver. Effects of surface roughness on the intensity of forced convection are quantified by application of Colburn analogy between heat and momentum transfer in the boundary layer, which allows assessment of heat transfer coefficient for known friction coefficient, determined by CFD. The computational method includes determination of the surface distribution of mass of captured water in icing conditions. The model of freezing of captured water accounts for generation of heat due to latent heat of captured water droplets, temperature recovery in boundary layer and kinetic energy of captured droplets. The sinks of heat include forced convection, heating of super cooled droplets, conduction of heat through the ice layer and sublimation. The mathematical model is implemented as user-defined function module in ANSYS Fluent solver. The results include effects of deposited ice, including increased surface roughness on aerodynamic characteristics of an airfoil.
Źródło:: Journal of KONES; 2018, 25, 3; 437-443
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 11.

Tytuł:: Concept of the automatization of dangerous driving manoeuvres
Autorzy:: Gidlewski, M.
Jemioł, L.
Żardecki, D.
Powiązania:: https://bibliotekanauki.pl/articles/247675.pdf
Data publikacji:: 2018
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: motor vehicle
active safety
lateral dynamics
avoidance automatization
obstacle voidance
model tests
simulation tests
pojazd silnikowy
bezpieczeństwo aktywne
testy modelowe
testy symulacyjne
Opis:: Automatic control is one of the main characteristic features of the present-day “electrified” motor vehicle. The avoidance of a suddenly appearing obstacle, including a rapid lane-change manoeuvre, is counted among the driving manoeuvres that are most dangerous and difficult to be automatized. Note that this seems to be a fundamental problem for autonomous cars. The authors have shown general vehicle automatization concepts derived from the control systems theory. Against this background, they have presented results of their own analytical studies and simulation research related to the system of automatic controlling of a rapid lane-change manoeuvre. A controller algorithm developed within this work, where a simplified reference model of the lateral dynamics of a motor vehicle was used (transmittance-type model based on well known “bicycle model” but transformed and linearized), was successfully examined in exhaustive simulation tests. The virtual object used for the simulation tests was an extensive simulation model (3D, nonlinear, MBS type) of a two-axle motor truck of medium load capacity, driven with quite a high speed. This detail model had been experimentally verified. In the article, only a fragment of a large research project has been described.
Źródło:: Journal of KONES; 2018, 25, 1; 111-122
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 12.

Tytuł:: Influence of freeplay and friction in steering system on double lane change manoeuvre - modelling and simulation studies
Autorzy:: Więckowski, D.
Żardecki, D.
Powiązania:: https://bibliotekanauki.pl/articles/242049.pdf
Data publikacji:: 2011
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: vehicle dynamics
steering system
freeplay
friction
mathematical models
luz(...) and tar(...) projections
simulation studies
sensitivity analysis
optimization of maneuver
double lane change maneuver
Opis:: Modelling and simulation investigations of a car non-linear dynamics with regard to freeplay (backlash in steering gear) and friction (kinetic and static friction in king-pins) is always a challenge for researchers. Fortunately, by special luz(...) and tar(...) projections and their mathematical apparatus the elaborated models and simulation procedures of stick-slip phenomena in a steering system are managed in efficient forms (without any entangle constraints) even for optimization and sensitivity studies. Exactly, the presented studies deal with problems of sensitivity of optimized maneuvers for vehicle models considering freeplay / friction effects. Double lane change maneuvers (overtaking and avoiding) are discussed. A criterion function refers to several evaluations (precision of maneuver, calm steering, feeling of comfortable travel). The optimization of steering wheel angle signal is done on a reference model with "nominal" freeplay and friction parameters. Such input signal is applied to a "real" vehicle having "real" freeplay and friction parameters. The differences of output signals as well as differences between criterion function values are a subject of sensitivity analysis. The sensitivity of reference models on a variation of freeplay and friction parameters appears as important from theoretical as well as practical points of view. The paper takes up the problems of sensitivity analysis of steering system model applied for synthesis steering algorithms for a double lane change maneuver.
Źródło:: Journal of KONES; 2011, 18, 2; 483-492
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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