air flow

Airflow pattern in an indoor sports hall of 17,325 m3 located in the sports complex of City University of Hong Kong has been investigated by computational fluid dynamics technique. The turbulence flow was taken into account by using Renormalisation Group method (RNG) k-e model. The objectives of this study are to obtain a preliminary understanding of the airflow pattern and evaluate the badminton 'playing zone' within which there should be no disturbance to the badminton shuttle behaviour.

By using the technique of turbulent large eddy simulation (LES) and finite element method (FEM) of computational fluid dynamics (CFD), the three dimensional flow fields in vector flow clean-room under empty state and static state condition were predicted. The partly expanded Taylor-Galerkin discretization scheme cooperated with implicit stream-upwind diffusion effect was used to deduce the finite element formulation of basic equations through Gauss filtering. The subgrid model of vortex viscosity was adopted in the numerical simulation.

A one-dimensional unsteady flow model with a moving pollutant source is used for calculating airflow velocity and pollutant distribution inside the single-track railway tunnel when a train passes through it. Calculations are made about the distribution of pollutant concentration inside the tunnel when a train passes through it under the conditions of different tunnel lengths, different amount of pollutant emissions, etc.

This paper presents the concepts of partition by aero-dynamic means; mentions that vertical current partitioning, horizontal current partitioning and displacement ventilation (DV) are the main measures on partition in large spaces; introduces ways of achieving vertical current partitioning, horizontal current partitioning and DV and the former two ways' numerical simulation conclusions.

This paper investigates ventilation characteristics and room airflow distributions in a workstation area of an office building with a personal environmental system. A personal environmental system is generally believed to be able to provide better thermal environment with less heating and cooling energy consumption. An underfloor air conditioning system with and without a desk-mounted PEM (Personal Environmental Module) is compared. A tracer gas experiment using a SF6 gas is performed to measure local supply index and room mean ventilation effectiveness.

Velocity and turbulence intensity profiles of airflow inside a section of Boeing 737 aircraft cabin were measured using PIV technique. The purpose of the measurement was to provide experimental data for the validation of CFD models being developed for evaluation of air quality and thermal comfort. The test section is approximately 5.6 m long, 2.8 m high and 3.4 m wide, holding 18 passenger seats distributed in 3 rows. A thermal manikin that accurately reproduces the geometry and heat generation of a human being was seated in one of the seats to simulate the human body.

The purpose of this article is to evaluate the performance of an irregular grids finite volume method described in previous article with the use of standard test problem. In this regard, lid-driven cavity and skewed cavity flow have assessed the accuracy of the algorithm. The ability of the method to handle complex geometry is illustrated through some examples of airflow distribution in buildings with complex geometric configuration.

Measurement data and analysis of air distribution in one gymnasium is presented in which the airflow is isothermal. The region considered includes both workaround and non-workaround, which can describe the airflow pattern of this gymnasium correctly. Based on measured data, the airflow pattern of the HVAC system is analysed. And the characteristic of airflow pattern in this kind of large space is summed up. Then some conclusions are drawn as a guide for airflow pattern designing in large space of the similar type.

The potential of natural ventilation control techniques when applied to full scale buildings is investigated with the use of both experimental and theoretical tools. An outdoor test cell was used to conduct experiments and two window types (bottom hung and sliding) were tested in different configurations under various meteorological conditions. Describes how theoretical methods for calculating airflow rates through the windows were developed, based on the experimental results and specific modelling activities. On comparison, good agreement was observed.

Describes a numerical simulation of carbon dioxide dispersion as a result of occupant breathing in the enclosed space of an auditorium. Considers lighting equipment, number of occupants, two different ventilation systems, air induction and abduction flow rate. Uses three dimensional geometry and turbulence effects.