As the thermal sensation of humans depends directly on heat transfer characteristics between the body surface and the surrounding environment, it is very important to clarify the heat transfer characteristics of a human body surface in detail. This paper describes a combined numerical (NOTE I) simulation system of airflow, thermal radiation and moisture transport based on a human thermo-physiological model used to examine the total (sensible + latent) heat transfer characteristics of a body surface. The human body is assumed to be naked (NOTE 2).
An application of the systemic approach is presented for the study of the ventilation of a room in an industrial facility. First, a series of tracer gas experiments was made with a radioactive tracer. Analysis of the Residence Time Distribution (RTD) curves, supported by some CFD, then enabled to build a simple zonal model for the description and quantification of the observed air flow patterns. This model was able to reproduce the experimental RTDs inside the room as well as at the exhaust.
The impact of the radiation absorbed by room air moisture 011 heat transfer and air temperature distribution was investigated. Both analytical and CFO approaches were used. For large spaces such as atria, industrial workshops, hotel lobbies, and aircraft hangers, the neglect of radiation absorbed by the moisture within the air volume can lead to significant errors.
Experiments have shown that exhalation from one person is able to penetrate the breathing zone of another person at a distance. Computational Fluid Dynamics (CFO) is used to investigate the dependency of the personal exposure on some physical parameters, namely: Pulmonary ventilation rate, convective heat output, exhalation temperature, and cross sectional exhalation area. Full-scale experimental results are used to calibrate/validate the CFD model. Respiration, although an inherently transient phenomenon, is simulated by steady-state CFD with reasonably good results.
In this paper, the airlfow and temperature distributions in a commercial kitchen are simulated based on the k- E model, and the ventilation efficiency is investigated for three types of ventilation systems. The result of this simulation shows that the suitable supply method of the outdoor air and the conditioned air can give high ventilation efficiency, and thus the kitchen can be kept comfortable with relatively low energy consumption.
The coupling of simulation methods is an interesting way to get improved or new results concerning thermal conditions in ventilated, heated, and air conditioned rooms. Some results are given for an investigation of a room in a low energy house by building simulation including CFO and the simulation of several heating systems. Comparative studies are done in two different ways. The first way serves to get results about different heating systems concerning thermal comfort and energy consumption and the second one to study the influence of the CFO calculation on the results.
A Computational. Fluid Dynamics technique is employed to predict the two dimensional turbulent air flow which is created by an Aaberg slot exhaust hood reinforced by a two-dimensional wall jet flow. The standard turbulent k-e model, control volume method and SIMPLE algorithm are tised to simulate the air flow. The numerical results for the effect of the Aaberg slot exhaust hood on the air flow pattern, shape of the capture region and the velocity distribution of the capture region in the system are presented.
The paper presents a mathematical model, implemented in a general computer code, that can provide detailed information on velocity and temperature fields as well as pollutants concentrations prevailing in three-dimensional buildings of any geometrical complexity, for given external meteorological conditions. The model involves the partial differential equations governing flow and heat transfer in large enclosures containing heat sources. Turbulent flow is simulated and buoyancy effects are taken into account.
Using isothermal full-scale experiments and 3-dimensional CFD simulations it is investigated how normal office furniture influences the air movements in a mixing ventilated room. Two different types of inlets are used in the experiments and a set-up with normal office furniture is made. The set-up is simulated with one of the inlets where a volume resistance represents the furniture. The jet under the ceiling is investigated and it is found that the normal office furniture does not influence the air movements in the upper part of the room.
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