AIVC - Air Infiltration and Ventilation Centre

Search form

EBC

You are here

Home

numerical modelling

Experimental and numerical investigation on temperature and air velocity distribution in a room equipped with split-system air conditioner.

Split-system air conditioning is increasingly usedapplications, owing to its low cost and installationboth for residential and commercialease. The indoor split-system unit iscommonly of the wall-mounted type and, due to its dimensions and position, very often itgives rise to appreciable air velocities and temperature gradients in the occupied zone of theroom. This work reports and discusses some experimental data collected in a test room withwall-mounted indoor unit, under different operating conditions.

Numerical prediction of mixed turbulent airflow within a cavity using various turbulence models.

The overall objective of the present work is to evaluate the performance of three turbulence models, with a view to predicting characteristics of airflow within an anisothermic cavity. The standard K-c. model, the Renormalisation Group model (RNG) and the Reynolds stress model (RSM) are used in conjunction with the Fluent code. The accuracy and the relative performance of the three models are evaluated by comparing their numerical results with experimentally obtained data. This comparison is made for the constant flow rate of a twodimensional turbulent mixed convective airflow.

Numerical simulation of the air cooling by natural ventilation inside the "Maison ronde" of Botta.

The present study applies the N3S CFD code to the air cooling simulation on an "architectural reference object", namely the "Maison Ronde" of Mario Botta. The summer night situation is examined when natural ventilation creates indoor air motion and cools the building structure. The transient behavior of the walls is represented by a thermal model coupled with the CFD code. The simulation evaluates the unsteady temperatures of the outdoor and indoor air flow together with those of the wall surfaces.

Integral simulation of the human thermal system.

In this work a numerical model that permits to simulate the human body thermal system is presented. This computational model is based on the integral energy balance equation for the human body tissue, arterial and venous blood and mass balance equation for the blood.

Effective radiation area of human body calculated by a numerical simulation.

A numerical simulation method is developed for predicting the effective radiation area and the projected area of a human body for any postures. This method is based on the solar heat gain simulation for buildings. To confirm the validity of the present method, predicted effective radiation area factors and projected area factors for both standing and seated person are compared with those by the measurements. It was found that predicted values agree quite well with those by the subjective experiments within 10% accuracy.

New scales for assessing ventilation performance.

Several new scales have been developed to quantify fresh air diffusion and contaminant dispersion in ventilated spaces. The local purging effectiveness is proposed for analyzing the individual contribution of each supply opening for a multi-inlet system. The local specific contaminant-accumulating index is defined to indicate the tolerance of a ventilation flow to contaminants. Furthermore, the regional purging flow rate, Up, is re-embodied in a simple expression different from the previous description.

Influence of various factors on the predictions furnished by CFD in cross-ventilation simulations.

The results of various numerical simulations of wind induced flows through large openings in a room are presented. The study is parametric on the sizes and relative positions of the openings and the wind direction. Various grid densities have been used. Grid independency for the presented results is demonstrated. Validation of the numerical approach is performed using measurements on a test cell with a single opening. The influence of the inflow wind profile is studied. It is shown that different flow patterns are induced within the dwelling when different profiles are assumed.

Non-passive particle dispersion in a displacement ventilated room - a numerical study.

Health effects caused by aerosol air pollutants in the breathing air is a main target for occupational health investigations. The effects of aerosol particles on health usually depend on the dose of particulate matter (PM:) retained at various locations of the respiratory tract. Displacement ventilation has been proved to be an effective ventilation system for the removal of passive pollutants in many buildings. The question is often asked about the performance of non-passive particle removal in a room ventilated by displacement ventilation.

Pages