Iveta Skotnicova

Effect of Non-Uniform Temperature Distribution over the Cross-Section in Steel Frame Structure

The paper deals with the effect of non-uniform temperature over the cross-section in the steel frame structure under fire loading. The unequal temperature distribution causes additional bending moments in statically indeterminate structures. Numerical results of thermal and structural analysis from the commercial computer software ANSYS are compared with the experimental measurements on the steel frame exposed to high temperature.

Evaluation of thermal comfort of the internal environment in smart home using objective and subjective factors

In accordance with the requirements for the optimal control settings of the operating and technical functions in Smart Home (SH) in order to reduce SH operating costs, it is also necessary to provide healthy microclimate and the required quality parameters of the SH internal environment in the individual SH rooms. The article describes the basic principles and methods of evaluation of thermal comfort of the internal environment using objective and subjective factors. The experimental measurements of objective parameters of the internal environment and thermal comfort evaluation were conducted in a selected SH room in a wooden building of the passive standard located in the Faculty of Civil Engineering, VSB - TU Ostrava.

Experimental and Numerical Analysis of Steel Frame Structure Exposed to High Temperature

Abstract Structures exposed to fire loading, where supports prevent thermal expansions, must be calculated according to the basic principles of mechanics while respecting the effect of rising temperature on the structure and its effect on the value of variable material properties at the time of fire. The paper analyzed and compared results of the experiment aimed to verify the behavior of statically indeterminate steel frame exposed to high temperature and numerical modelling using finite element method in the ANSYS software.

Dynamic Heat Transfer through the External Wall of a Timber Structure

The article compares results of temperature and heat flux measurements in the external wall of a real timber structure with results obtained by numerical modeling using the finite element method in the ANSYS software. The measured temperature values are compared with results obtained from numerical simulation of dynamic heat transport using non-stationary boundary conditions. In the article there is evaluated a suitability of theoretical numerical calculations for a thermal field and heat flux prediction in a building structure.

Experimental Measurements and Numerical Simulations of Dynamic Thermal Performance of External Timber Frame Wall

The aim of this article is to contribute to the summer thermal performance of external timber frame wall by the simultaneous use of experimental measurements and numerical simulations. The measurements were taken on an experimental timber frame passive house. The numerical modeling of the external wall using a dynamic simulation program ANSYS. The results of research are presented and discussed. It is shown that the numerical simulation methods are suitable tools for the prediction of thermal behaviour of light-weight timber-based construction.

Using of aerogel to improve thermal insulating properties of windows

Abstract For the best possible thermal-technical properties of building structures it is necessary to use materials with very low thermal conductivity. Due to the increasing thermal-technical requirements for building structures, the insulating materials are developed. One of the modern thermal insulating materials is so-called aerogel. Unfortunately, this material is not used in the field of external thermal insulation composite systems because of its price and its properties. The aim of this paper is to present possibilities of using this insulating material in the civil engineering - specifically a usage of aerogel in the production of windows.

Numerical Models of Wind Effects on Temperature Loaded Object

Wind climate influencing wind loads on buildings and other structures, as well as the dispersion of pollutants from various surfaces is essentially determined by small-scale motions and processes occurring in the atmospheric boundary layer (ABL). The physical and thermal properties of the underlying surface, in conjunction with the dynamics and thermodynamics of the lower atmosphere influence the distribution of wind velocity in thermally stratified ABL. Atmospheric turbulence is characterized by a high degree of irregularity, three-dimensionality, diffusivity, dissipation, and a wide range of motion scales. This article describes a change of selected turbulent variables in the surroundings of flow around a thermally loaded object. The problem is solved numerically in Ansys Fluent 13.0 software using LES (Large eddy simulation) models as well as the Transition SST (Shear Stress Transport) model that is able to take into account the difference between high and low turbulence at the interface between the wake behind an obstacle and the free stream. The results are mutually compared and verified with experimental measurements in the wind tunnel.

Numerical and Experimental Models of the Thermally Stratified Boundary Layer

Abstract The article describes a change of selected turbulent variables in the surroundings of a flow around thermally loaded object. The problem is solved numerically in the software Ansys Fluent using a Transition SST model that is able to take into account the difference between high and low turbulence at the interface between the wake behind an obstacle and the free stream. The results are verified with experimental measurements in the wind tunnel.

Analysis of Predictive Calculation Methods of Airborne Sound Insulation

Acoustic properties of building structures are currently very actual theme with regard to the development of new building and insulating materials, while the methods for estimating the airborne sound reduction index evolve mainly from the second half of the 20th century. For mutual comparison of selected prediction methods and for determination of their suitability it has been provided a calculation of weighted sound reduction index RW [dB] from the input parameters of materials identified by laboratory measurements, calculation of weighted apparent sound reduction index R ́W [dB] and these values were compared with in-situ measurements. The aim of this paper is to determine the most appropriate method to calculate RW [dB] and R ́W [dB] values of lightweight building constructions with regard to their practical applicability, accuracy of estimation and complexity of the calculations.

Numerical and Experimental Modelling of an Air Flow Field in the Chamber of a Rectangular Cross-Section Contraction

The article describes the study of turbulent characteristics in the enclosed chamber of a rectangular corss-section nozzle using numerical calculations. Suitable Ansys Fluent software models were selected based on the measurements results comparison in an aerodynamic tunnel as the fluid exits the nozzle. Special attention is paid to profile velocity near the peripheral wall of the observed enclosed chamber in order to confirm the optimal shape of the contraction and thus take steps towards a high quality velocity field.