Coupling CFD and multizone models can avoid their respective drawbacks in predicting airflow andcontaminant concentrations distribution in buildings. Two kinds of boundary conditions are commonlyexchanged between them. The multizone model can give either pressure or mass flowrate boundaryconditions to CFD. This study analyzes in detail the impact of each of the boundary types on the CFDdomain, and compares them with a full CFD simulation without coupling.
The air quality in laboratories has a profound affect on occupant health and safety. Reducing the timeof exposure and the amount of contaminant can improve the occupant environment and have directimpact on health and safety. In this study, a novel ventilation system which introduces benchexhausts is proposed. The system offers the potential for application in new and existing researchlaboratories to effectively remove airborne contaminants at the bench using a technology that is costeffective and efficient.
The summer natural wind environments inside an airport terminal building under two cases aresimulated by the method of computational fluid dynamics (CFD) in this paper. The two cases havedifferent opening areas for glass curtain wall. Case 1 has the opening ratio of 10% while Case 2 has30%. The paper also uses DeST to simulate the annual natural temperature distribution under twokinds of opening ratio in a whole year.
This study evaluated and optimized the thermal environment inside an air-conditioned train stationbuilding using the computational fluid dynamics (CFD) method. The impacts of some air-conditioningdesign parameters such as supply air temperature, velocity, altitude and incidence angle on indoorthermal environment were discussed. The primary air-conditioning design scheme was optimized.
The performance of indoor airflow for the office room with the hybrid air-conditioning system has beeninvestigated by means of CFD analysis. The hybrid air-conditioning system is composed of under floorair supply outlets for task zone and the natural ventilation openings for ambient zone. The measureddata (Kotani et al. 2006) at the office room in existence was used as the boundary condition of the flowrate of each natural ventilation opening and task flow outlets for CFD.
In Japan, sick house syndrome has been a problem owing to air tight houses and change of a life style.For this reason, the building standard law was revised in July, 2003, and it was defined that 0.5 times ormore per hour need to be ventilated in the case of a residential room.On the other hand, radiation heating systems, such as a floor heating, have spread in the residence inrecent years. The features of these heating systems are that an indoor air-flow distribution is uniform,that the distribution difference of an indoor vertical temperature is small, etc.
Conventional method to predict ventilation rate induced by wind is based on the orifice equationassociated with the discharge coefficient and wind pressure coefficient. In the cross-ventilationphenomena, however, this method has a problem due to the difficulty to predict resistance of thebuilding related with total pressure loss. In this paper, therefore, the stream tube caught by the inletopening is analyzed to investigate the pressure loss due to the transformation (and possiblyconvergence and divergence) of the stream tube.
Increase in high-rise residential building has changed the envelope of residential building to aluminumcurtain wall which requires the use of the single-sided ventilation to be used instead of the crossventilation. It causes dissatisfaction mainly with indoor air velocity and ventilation volume. Therefore,the objective of this study is to improve the natural ventilation performance of high-rise residentialbuilding by opening design. To improve the natural ventilation performance in single skin faade, theeffect of different types of window will be evaluated.
This paper reviews the previous attempts to evaluate the Indoor Air Quality (IAQ), investigatespreviously proposed IAQ factors and analyses the evaluation methods of these factors. The presentwork introduces, also, a new hypothesis of the optimum HVAC airside system design of the surgicaloperating theatres to achieve the comfort and hygiene levels. The present work is devoted to proposeand formulate a new scale capable of adequately evaluating the airflow pattern in the surgicaloperating theatres. The proposed new scale is proposed to cover the local and overall air qualityevaluations.
In this paper, the indoor environmental quality for the commuter train space was analyzed for assumingthe load factor of seat capacity to be a parameter of analysis. Especially flow fields, temperature and airquality distributions in vehicle space were analyzed by using CFD technique. Furthermore, it reports onthe result of examining the controllability of indoor climate in the vehicle when the displacementventilation system was applied in it.