English

The paper describes the design of a fire and a smoke source for scale-model experiments with smoke ventilation. It is only possible to work with scale-model experiments when the Reynolds number is reduced compared to full scale, and it is demonstrated that special attention to the fire source (heat and smoke source) may improve the possibility of obtaining Reynolds number independent solutions with a fully developed flow. The paper shows scale-model experiments for the Ofenegg tunnel case.

The air movement in the occupied zone of a room ventilated by displacement ventilation exists as a stratified flow along the floor. This flow can be radial or plane according to the number of wall-mounted diffusers and the room geometry. This paper addresses the situations where plane flow is obtained and a semianalytic expression for the velocity level in the occupied zone is given.

The techniques available for the simulation of the complex geometries common in air diffusers are quite different from the ones optimized for a complete room simulation. For this reason the full room simulation usually neglects the complexities of the diffusers introducing ad hoc boundary conditions
often requiring extensive experimental setups for a correct definition. An alternative approach could be the use of numerical analysis for the diffuser characterization. In this work a detailed analysis

Zoning room air conditioning strategy is based on the idea of controlling the conditions of one zone by supply air and, at the same time, utilizing the stratification of temperature and contaminants in another zone. The aim of this study was to assess the ability of CFD-simulation to predict the supply air flow pattern and the overall performance of the system. The study was based on a series of laboratory experiments and corresponding CFD-simulations.

Airflow characteristics in the air-conditioned spaces play an important role to obtain the comfortable and hygienic conditions. This paper utilizes a 3D time dependent Computational Fluid Dynamics (CFD) model to assess the airflow characteristics in four different air-conditioned spaces. It was found that the location of the air extraction port represents a critical design factor and would have a direct effect on the heat removal efficiency and the energy efficiency of the air-conditioning system from the airside wise.

An energy simulation program, ESP-r, was used for simulation of the energy requirements and indoor climate in a well-insulated terraced house in Sweden. A parameter study was performed to investigate the influence of different control schemes on energy requirement. The influence on both energy requirement and indoor climate were analysed for two different measures. Changed placement of the air temperature sensor in the heating system decreases the energy demand without deteriorating of the indoor climate.

The selection and design of air conditioning systems in Hungary are based on a determined modelling state. In the last decade this was a safe enough basis for the management of systems. As a result of the changes in the macroclimate, however, there has been a major increase in summer temperatures. Taking into account this fact and the need to develop the earlier deterministic modelling techniques we chose to focus on risk-based modelling.

This paper describes a comparison between internal and external run-time coupling of CFD and building energy simulation software. Internal coupling can be seen as the traditional way of developing software, i.e. the capabilities of existing software are expanded by merging codes. With external coupling, two or more software packages run simultaneously while exchanging calculation results at appropriate time intervals.

The conversion of CAD models into 3D Cartesian-defined geometries is presented, and a two-pass algorithm to perform the transformation is described. The methodology for implementing the numerical solution of fire dynamics problems involving the FDS simulation program is tested. The results from these predictions are visualized on the original geometry using elements which take into account the optical properties of the phenomena for a realistic rendering of smoke and fire.

The airflow conditions in an experimental pig housing unit are examined both experimentally and numerically (simulation) with particular focus on the airflow conditions in the occupational zone of the animals. Two heating setups are used, and the temperature is measured in a horizontal profile at the floor and at the ceiling. Good concordances between the measurements and the simulations are reached at the floor level. At the ceiling level, the conformity to the measuring results is unsatisfactory.