Influence of cooling strategies on the air flow pattern in an office with mixing ventilation

In this study, an office with mixing ventilation is considered. The CFD analyses show that for high cooling loads it is useful to couple a cold ceiling to primary air system

Integration of CFD and genetic algorithms

This paper deals with the integration of CFD analysis tool with genetic algorithms. This integrated process presents advantages in generating design alternatives that tally with multiple design, thermal and ventilation criteria.

Improving CFD Simulation of chilled ceilings

This paper deals with a CFD simulation of a chilled ceiling in a test chamber. The results demonstrate that a slight non-uniformity in cooling power of the ceiling panels produces a great asymmetry in predicted room airflows.

Extension of the kinetic energy model for calculation of the zone average air velocity

The aim of this work was to develop a new calculation method of the zonal air velocity in ventilated room during the design stage. The verification showed a good correlation between the method and the experimental data.

Modeling of complex air diffuser for CFD simulation. Part 2 : air diffuser model based on airflow data obtained by unstructured CFD simulation

In this paper the application of CFD simulation with unstructured fine elements system was carried out to obtain airflow data for the boundary conditions for an air flow.Tthe results were compared with the measured data.

Validation of turbulence models using topological aspects

In this paper, 2D - CFD calculations of the flow are carried out . Two different turbulence models were employed and the results compared. The differences between experiments and calculations are explained by introducing a topological apparatus

Non-isothermal airflow pattern designing by CFD method.

To simulate non-isothermal indoor airflow more quickly and correctly, a turbulence model is performed in STACH-3, the 3-D CFD code developed by Tsinghua University. Validation reveals that it is satisfied for non-isothermal indoor airflow. The air distribution in an actual conference room with VAV system is numerically solved by CFD method, and the conventional jet theory method is used for a comparison of the results. Subsequently an analysis is done of the cold air draught and hot air climbing problems.

A method of test to obtain diffuser data for CFD modelling of room airflow.

The use of two simplified models was demonstrated in this study, the box and momentum methods, in order to simulate complex diffusers in room airflow modelling by CFD. Additional flow information is needed by the two methods, which is not available from product catalogues of diffuser manufacturers - the information required includes the distribution of discharge air velocity, box size and flow direction. A test method was developed on how to obtain the additional information with minimal effort under ASHRAE standard 70-1991.

CFD prediction and tracer gas measurement of an indoor car park naturally ventilated.

Presents CFD simulations and field experiments on ventilation efficiency in an underground car park with natural ventilation. A series of experiments were carried out to validate the results of the CFD calculation, looking at the decay of the concentration of tracer gas (SF6) in the area studied. A long/linear analysis of concentration with time was used to deduce the air change rate. It was found that experimental data were in good agreement with the CFD simulation result.

Validation of boundary conditions for CFD simulations on ventilated rooms.

The application of Computational Fluid Dynamics (CFD) for ventilation research and design of ventilation systems has increased during the recent years. This paper provides an investigation of direct description of boundary conditions for a complex inlet diffuser and a heated surface. A series of full-scale experiments in a room ventilated by the mixing principle have been performed for validation of the models. The experimental results include measurements of temperature as well as measurements of velocity and turbulence by Laser Doppler Anemometry (LDA).