• 설비공학논문집
• /
• 제23권10호
• /
• pp.639-645
• /
• 2011

The object of this study is to analyze and evaluate outdoor wind pressure effect in a high-rise residential building when seasonal wind blow on coast area. The target building consists of 3 tower buildings over 250m in height. For the evaluation of the outdoor wind effect, CFD simulation was performed. The results of the simulations are as follows : 1) In that case of high-rise building, horizontal stream is more affected than vertical stream. 2) In case of summer season northeasterly wind, building pressure distributions are unstable and surface pressures of outside are effected respectively. 3) In case of winter season westerly wind, building preassure differentiations are not so much because of screening effects of the B, and the C buildings. 4) In case of winter season northwesterly wind, front wind affects on the A building directly because of no obstacles.

• KIEAE Journal
• /
• 제12권2호
• /
• pp.117-124
• /
• 2012

The purpose of this study is to investigate the change of wind environment for different building arrangement. In this study, we analyze outdoor wind environment on different building arrangement that take same floor area ratio using the CFD (Computational Fluid Dynamics) method. We do not consider the effect of temperature. Building arrangements of low density, different hight and a lot of green area will change the effect of wind environment. The eight different arrangements of buildings are studied in this paper. In these calculations, we know the different arrangement of buildings change outdoor wind environments. Especially, reducing the number of building and crossing the different height of buildings have a good kind of wind environment at the same floor ratio. We know that these arrangement of buildings to reduce the heat island phenomena on city plan.

• 설비공학논문집
• /
• 제29권4호
• /
• pp.175-184
• /
• 2017

With the improvement of living standards, the ventilation for the mitigation of indoor or outdoor air-pollution problems has recently attracted a lot of attention. Consequently, the ventilation for the supply of outdoor fresh air into a room is treated as an important building-design factor. The ventilation is generally divided into the forced and natural types; here, the former can control the ventilation rate by using mechanical devices, but it has the disadvantages of the equipment costs, maintenance costs, and noise generation, while the latter is applied to most workshops due to the absence of noise and the low installation and maintenance costs. In this experimental study, the ventilation performance of a typical rotating-type natural ventilator, which is called a "wind turbine," was investigated with the outdoor-wind velocity and the indoor/outdoor-temperature difference. From the experiment results, it was confirmed that the temperature difference of $10^{\circ}C$ corresponds to the ventilation driving force with an outdoor-wind velocity of 1.0 m/s. Additionally, the intake-opening area of a building also exerts a great effect on the ventilation rates.

• Wind and Structures
• /
• 제11권1호
• /
• pp.51-70
• /
• 2008

CFD is applied to evaluate pedestrian wind comfort at outdoor platforms in a high-rise apartment building. Model validation is focused on generic building sub-configurations that are obtained by decomposition of the actual complex building geometry. The comfort study is performed during the design stage, which allows structural design changes to be made for wind comfort improvement. Preliminary simulations are performed to determine the effect of different design modifications. A full wind comfort assessment study is conducted for the final design. Structural remedial measures for this building, aimed at reducing pressure short-circuiting, appear to be successful in bringing the discomfort probability estimates down to acceptable levels. Finally, the importance of one of the main sources of uncertainty in this type of wind comfort studies is illustrated. It is shown that the uncertainty about the terrain roughness classification can strongly influence the outcome of wind comfort studies and can lead to wrong decisions. This problem is present to the same extent in both wind tunnel and CFD wind comfort studies when applying the same particular procedure for terrain relation contributions as used in this paper.

• KIEAE Journal
• /
• 제15권2호
• /
• pp.123-131
• /
• 2015

Purpose : Improvement of indoor thermal comfort and reduction of the energy consumption in building can be obtained by applying a double skin facade system. In order to achieve effectively this purpose, design team would have to perform easy and appropriate performance analysis for making better design decision during the design process. Method : This paper focus on the natural ventilation performance of a multi-story type double skin facade with main causes which are pressure difference according to the wind and temperature difference between indoor and outdoor (Buoyancy Effect). Using this main causes, the natural ventilation ratio of wind effect-to-buoyancy effect in cavity of multi-story type double skin facade were analyzed through the performance analysis results of CFD (Computational Fluid Dynamics) simulation. Result : When the wind velocity was 2m/s, the ventilation rate in the cavity was highest. If wind velocity was slower than 2m/s wind velocity, buoyancy effect has more influence on the ventilation rate in the cavity, and if wind velocity was faster than 2m/s wind velocity, wind effect has more influence on the ventilation rate in the cavity.

• 도시과학
• /
• 제8권1호
• /
• pp.25-31
• /
• 2019

Infiltration affects indoor environmental and air quality and energy consumptions in buildings. Especially, airflow and the infiltration are more remarkable in high-rise buildings due to the air-driving forces (stack and wind effects). Thus, it is important to understand infiltration distributions in high-rise residential buildings. In this study, the weather-driven infiltration is characterized from the viewpoint of interactions between external wind and stack effect in high-rise residential buildings. To calculate accurately the annual infiltration distributions, this study also suggests an airflow and thermal simulation method with a two-step calibration of air-leakage data. The simulated results show (1) how the interaction between stack and wind effects induce infiltration types (outdoor and interzone air infiltration) and (2) how much the interzone air infiltration (being ignored in previous studies) occurs due to the stack effect, as well as the outdoor air infiltration rates.

• 한국전기전자재료학회논문지
• /
• 제19권5호
• /
• pp.480-485
• /
• 2006

A research was undertaken on the thermal properties and behavior of the conductors in a controlled chamber, which was designed to implement the outdoor air temperature, heat and wind conditions With ACSR $410mm^2$ overhead conductors, we measured the maximum temperature of the conductors and the temperature gradient from the core to the surface regions as a function of current, tension, wind velocity and outdoor air temperature. This test also provided a comparative analysis between the measured temperature values of conductors in the controlled chamber and the theoretical calculations of ANSI/IEEE at normal condition. There was not much influence of tension on the conductor temperature. However, the compactness of conductor wires increased with an increase in tension, which eventually increased the coefficient of effective thermal conductivity and, accordingly the conductor temperature was reduced more or less.

• 대한건축학회논문집:계획계
• /
• 제35권6호
• /
• pp.27-37
• /
• 2019

This study focused on the possibility of reducing the cooling load through the change of micro climate in the outdoor space during summer season. This study proposes an efficient planning model by comparing the effects of urban heat island mitigation through wind path planning, outdoor space vegetation, and exterior material change by using the basic model of the street-oriented block housing proposed in the previous research by the same author. As a result, the most effective wind path planning strategy in the street-oriented block housing was the change of the air flow through the mass height adjustment. When the tall building masses were staggered and arranged in a balanced manner, the overall wind environment could be improved. The greater the height difference between low and high masses, the better the air flow was shown. It was also important to arrange the building masses so that the inlet of the main wind was open and to allow the external space to connect to the adjacent block to create a continuous flow. The change of outdoor space vegetation and flooring, and the formation of wind paths through the opening of lower part also showed the effect of heat island reduction. In addition, the change of PMV in summer was the biggest influence of shadow by tall building mass. Attention should be paid to the fact that high-albedo exterior materials are adversely affected by multiple reflections in dense street-oriented block housing. The use of albedo of the exterior material showed that it is necessary to pay attention to apply in the high density block housing. This is attributed to the rise of the temperature due to the absorption of energy into the low-albedo flooring, where the high-albedo exterior causes multiple reflections.

• 설비공학논문집
• /
• 제28권2호
• /
• pp.55-62
• /
• 2016

The air flows in building caused by thermal buoyancy, known as the stack effect, have a pronounced influence on both the indoor environment (thermal environment, noise, draught and contaminant diffusion) and energy needs in high-rise buildings. Prior studies for airflow in high-rise buildings were focused on the degree of stack effect and countermeasures. The wind pressure was neglected during the calculation of the indoor airflow in high-rise buildings to clarify the effect of thermal buoyancy in previous studies. However, wind is an important driving force of indoor airflows in buildings with the stack effect. In this study, the effect of wind pressure on indoor airflow in high-rise building when the stack effect is dominant in winter was analyzed. In this paper, methods that involved considering the wind pressure in airflow network simulation were analyzed.

• 한국산업융합학회 논문집
• /
• 제2권1호
• /
• pp.19-25
• /
• 1999

A new urban design method from the viewpoint of climate is considered to be desired for urban life. The authors verified on an environmental planning based on new urban design concept which introduced the effect of sea breeze blowing along canals. The field observation of urban thermal environment were carried out to examine the cooling effects of a river through city. The observations were conducted to find the effect of a sea breeze and climate in summer along canals. Effective distance from the sea and cooling effect of the sea breeze on urban temperature was analyzed. The thermal index using outdoor environment was modified with New Effective Temperature ET*. On the basis of the observation. Human thermal comfort is relieved and affected by sea breeze blowing along canals. The canals were utilized as the trail on which sea breeze blows towards the center of city. From these results, The wind trail is one of the effective passive design method from the viewpoint of urban climate.