IBPSA2007

In order to make sustainable single houses, it is very important to control the outdoor thermal environment. Therefore, various relaxation methods for the outdoor thermal environment are often planned, e.g. utilizing of the cooling effect of a water face, arrangement of water permeable material, planting trees etc. In this paper, a coupled simulation of CFD and radiation transfer is conducted in order to evaluate the outdoor thermal environment in riverside detached single houses near to Tokyo in Japan.

Air age is an important parameter to assess indoor air quality in ventilated rooms. In order to consider the contribution of ductwork and recirculation, the concept of total air age was proposed for ventilation systems with ductwork and recirculation in previous study. In this paper, about 16 typical cases are simulated with computational fluid dynamics after introducing the method to calculate total air age for ventilation systems with only one AHU and one room in which several inlets and outlets exist.

With the rapid development of computers and CFD, pedestrian level wind study using CFD has become important in engineering design in recent years. In the United Kingdom, wind study is now a common engineering practice and a mandatory documentation for plan authority. The paper presents preliminary CFD simulation of pedestrian wind environment around buildings of typical configuration, size and orientation. The results were compared for flow pattern and the wind velocity amplification value at the pedestrian level, a horizontal surface 1.5 m above ground.

Scientific studies have linked particulate matter with a series of significant health problems. In ventilation systems, indoor particle concentration and dust load on air duct surfaces are two concerns for human health. PROBE-PM (Predicting code for building environment-particulate matter transport simulation), a code to simulate the particle transport in the whole ventilation system is developed.

A new concept, the spatial flow influence factor (SFIF), put forward by us in our previous paper, provides a new insight into the airflow structure. In this paper, several typical illustrative examples are presented to show: (1) how to optimally arrange the chemical pollutant sources and the occupied regions for a given indoor airflow; (2) how to optimize the position of adsorption materials. From the examples,  it is seen that the concept is powerful in the control of indoor air gas pollutants.

Here a generalized 3-D radiation simulation system is developed with Monte-Carlo and Gebhart method. There are two kinds of basic units in the system, which are surface unit for opaque objects and body unit for transparent objects respectively. When the bundles were emitted from certain point or surface with Monte-Carlo method, it would enter into an opaque surface or a transparent body. For the former, it would be reflected and absorbed. However, when the second situation happened, there is the third process named penetration beside above two processes.

The three-dimensional wind environment in Lanqiying community of Beijing city, which is complicated due to the dense distribution of the highrise buildings, is investigated by computational fluid dynamics method. The turbulent flow past the buildings is simulated by solving the incompressible Reynolds-averaged Navier-Stokes equations. Both the reverse flow between the buildings and the ecirculation of the wake can be observed. The spectrum analysis of aerodynamics coefficient are successfully obtained and compared with the twodimensional results.

Energy savings by integrating the daylighting availability in the electric lighting management contributes to the realization of ‘Green Building’. This paper provides a simulation and calculation of office building in North China with RADIANCE software on the basis of theoretical analysis, which focuses on the influence of Window-to-Wall Ratio (WWR), sill height, glazing transmittance and window shape on Lighting Savings (LS). The study finds out the relationship between those window parameters and LS. The results may be reference for  designers as daylighting is involved.

Computational fluid dynamics (CFD) is a promising method to study the urban built environment. However, the pecularities of the urban wind environment are difficult to simulate with a CFD package. The aim of this work is to develop CFD model capable of simulating the urban boundary layer which can then be used to investigate the effects of built form on the pressure coefficient regeme. The model concentrates on two aspcepts: the boundary conditions and domain size.

This paper highlights the difficulty of using energy simulations to answer general questions in typical  building design scenarios. By analyzing the question, it is identified that problems of a search-based nature may encounter situations where an exhaustive search is impractical with reasonable resources. This paper presents the method of using heuristics to solve such questions within just a few simulations. While the solutions may not necessarily be guaranteed to be global or ideal, they are optimal within reasonable limits and sufficient for the types  of questions addressed.