VUTS Liberec

Liberec, Czech Republic

VUTS Liberec

Liberec, Czech Republic
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Adamek K.,VUTS Liberec | Kolar J.,VUTS Liberec | Peukert P.,VUTS Liberec
AIP Conference Proceedings | Year: 2016

Many incidents of poisoning all the time became due to bad natural exhaust of burnt product from heating devices. The aim of this article is to simulate some reasons of it, therefore the content is focused on some influences, only - the vertical and horizontal shape of the outlet channel, the design of the chimney cap, situation of the surrounding walls, combined with the wind influence etc. It does not solve the possible bad maintaining of both chimney and device, bad supply of the combustion air etc. As main results of simulation there is presented an optimum cap shape of the chimney and an unsuitable influence of the unsteady starting of the flow just after the burner ignition. © 2016 Author(s).

Tisovska P.,VUTS Liberec | Peukert P.,VUTS Liberec | Kolar J.,VUTS Liberec
EPJ Web of Conferences | Year: 2017

The main goal of the article is a verification of the heat transfer coefficient numerically predicted by two CDF platforms -ANSYS-Fluent and OpenFOAM on the problem of impact flows oncoming from 2D nozzle. Various mesh parameters and solver settings were tested under several boundary conditions and compared to known experimental results. The best solver setting, suitable for further optimization of more complex geometry is evaluated. © The Authors, published by EDP Sciences, 2017.

Kloucek V.,VUTS Liberec | Fabera J.,VUTS Liberec | Pryl S.,VUTS Liberec | Brozova V.,VUTS Liberec
Lecture Notes in Mechanical Engineering | Year: 2014

The contribution contains description of the anti-backlash designed planetary gearbox with Oldham couplings, integrated into chassis of an electric motor. The design is subject to a patent protection. The solution results of kinematics and dynamics of components, which held a general planar motion are presented. The following explains the power flow branching through transmission mechanism and the overall efficiency of mechanism is solved. The conditions for backlash elimination are discussed. © Springer International Publishing Switzerland 2014.

Adamek K.,VUTS Liberec | Zak J.,VUTS Liberec | Kavan P.,VUTS Liberec | Sidlof P.,VUTS Liberec | Kolar J.,VUTS Liberec
EPJ Web of Conferences | Year: 2014

The paper summarizes the results of several numerical flow simulations of force influence of air flows on the treated paper sheet to get a contactless fixing of the treated material during its passage through the machine and to prevent the contact of the sheet with the structural elements in the surroundings. © 2014 EDP Sciences.

Kolar J.,VUTS Liberec | Adamek K.,VUTS Liberec
WIT Transactions on the Built Environment | Year: 2012

This paper reports the numerical investigation and optimization of a damping unit where oil flow interacts with an elastic chocking plate. Chocking of flow from a by-pass valve is the basic principle of hydraulic shock absorbers. However, cavitation phenomenon caused by strong shocking occurs at high frequencies of an actuating movement and the original damping unit characteristic is being distorted. We used the computational fluid dynamic to minimize the distortion of characteristic as much as possible. To satisfy the high number of unsteady simulations, the involved fluid-structure interaction needs to be coupled in a different way than the routine is. The plate deformation is coupled with an average hydrodynamic loading pressure by a single afore-computed third polynomial equation being predicted by FEM. Numerical simulations of flow by the use of FVM exploiting dynamic mesh in Fluent commercial code then provides a flow field pattern and loading pressure within the unit itself. A User Defined Function (UDF) enables the deformation of the domain boundaries in a coupled way. Finally, the time dependency of the plate position and its dynamic behaviour is obtained. Highly dynamic manners appeared and numerous techniques providing a better stability of computations had to be investigated and developed. The state where the most cavity bubbles are being induced is further applied to shape optimization at the steady state. The shape-based similarity optimization of by-pass geometry is then carried out to minimize the formation of cavitation bubbles. © 2012 WIT Press.

OndrASek J.,VUTS Liberec
Mechanisms and Machine Science | Year: 2015

Very important mechanical objects are cam mechanisms whereas their dynamic properties affect the overall behavior of the given mechanical system. For this reason it is necessary to create a mathematical model of those objects whose main objective is to determine the time course of the dynamic behavior of the system. When creating mathematical models of combined cam mechanisms, there are used options and features of NX I-DEAS, MSC.ADAMS and MSC.EASY5 expert systems. This approach is shown in the design of the wire feeder drive of the nail making machine. The drive is designed by a cam mechanism with a radial conjugate cams and an oscillating roller follower. The aim of the analysis was to determine the characteristic dimensions of the cam mechanism. © Springer International Publishing Switzerland 2015.

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