An Overview of Unsteady Analysis Techniques for Natural Wind Turbulence and its Effects on Natural Ventilation

Focusing on the turbulence in natural ventilation and its impact on both occupant thermal comfort and building energy consumption, this paper presents a review of existing unsteady natural ventilation envelope flow models, as well as other techniques that have potential application to further our understanding of turbulence in natural ventilation and develop models which capture the dynamics and effects on thermal comfort.

Building Envelope Pressure Manipulation for Streamlined High-Rise Buildings

Methods of manipulating building envelope wind pressure distributions for application in the natural ventilation of high-rise buildings are presented using computer simulation methods. CFD was used to simulate the external flow while the multi-zone method was used to compute the flow distribution in the building interior. First, a 2-D CFD study was conducted to explore various techniques of manipulating the building envelope wind pressure distribution.

Dynamic thermal modelling and CFD simulation techniques used to influence the design process in buildings

This application paper outlines some innovative building simulation methodologies used to predict thermal performance of complex energy efficient systems using commercially available softwares. Industry case studies are presented to demonstrate how simulation can influence the design process with requirements varying from zero carbon emissions to optimum thermal comfort. Simplifications used to reduce computational time and handle software limitations are assessed in regards to model accuracy and the ability to influence the design decision process.

Simulating the effect of complex indoor environmental conditions on human thermal comfort

This paper describes the methods developed to couple a commercial CFD program with a multi-segmented model of human thermal comfort and physiology. A CFD model is able to predict detailed temperatures and velocities of airflow around a human body, whilst a thermal comfort model is able to predict the response of a human to the environment surrounding it.

A prototype mesh generation tool development for CFD simulations in architecture domain

Computational Fluid Dynamics (CFD) has been introduced to the architectural engineering and HVAC (Heating Ventilation and Air Conditioning) industry for decades. Its effectiveness in assisting the architects and engineers in the design process has been well acknowledged. However, the mesh generation process is complicated and time consuming, especially for modeling free form geometric artifacts, e.g., buildings in complex terrains or human bodies in the room. This paper presents the effort to apply quality mesh generation to CFD simulations in architectural applications.

Simulation and analysis of indoor gas leakage

The indoor fire induced by gas leakages can cause a lot of property losses and fatalities. One of the  primary fire reasons is the explosion caused by the leaked gas concentrated within the explosive limits and an ignition source offered. In the paper, the characteristics of indoor gas leakages are disscussed and the theoretical models of the release rate and diffusion of gas are presented firstly.

CFD modelling of double-skin façades with venetian blinds

This paper describes CFD modelling of Double Skin Façades (DSF) with venetian blinds inside the façade cavity. The 2-D modelling work investigates the coupled convective, conductive and radiative heat transfer through the DSF system. The angles of the venetian blind can be adjusted and a series of angles (0, 30, 45, 60 and 80 degrees) has been modelled. The modelling results are compared with the measurements from a section of façade tested within a solar simulator and with predictions from a component based nodal model. Agreement between the three methods is generally good.

Coupled Analytical Tool of Ventilation Calculation and CFD in Annexation System of Cool/Heat Tube and Natural Ventilation

Natural ventilation airflow rate is generally calculated using indoor and outdoor temperature difference without consideration of heat balance based on the vertical air temperature distribution in simple analytical method.

Research on prediction of wind environment around outdoor group objects

It is difficult to model those complicated objects around buildings, which will obviously affect the flow patterns and temperatures of the outdoor environment. In this paper new method is concluded to solve this kind of modeling problems. Those centralized objects are treated as porous media which will also affect the air flow and turbulence. New source terms are coded into the model to simulate the characteristics. In this way, we can easily model as many as influential factors into the simulation and save much computational time and get a satisfactory result.

Numerical simulation of outdoor thermal environment for a sustainable lake town

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.