English

The air flow pattern and temperature distribution in a naturally ventilated classroom were simulated using CFD techniques. The simulation model consists of equations for the conservation of mass, momentum and thermal energy, taking account of the effects of buoyancy and obstacles in the room. The well known k-e turbulence model was used to simulate the effect of air turbulence. Close to the inside surface of the room and the obstacle boundary, the wall-function equations were used for momentum and heat flux. Heat sources existing in the classroom were included in the simulation.

Mathematical models are presented that account for the mass transport processes associated with isothermal reversible sorption in building materials. These models account for a) the equilibrium limits of reversible sorption processes, b) boundary layer diffusion transport at the adsorbent surface, and/or c) diffusion transport within the adsorbent proper. Three distinct families of models are formulated with individual members of each family distinguished by the sorption equilibrium relation used in their formulation.

The developments in the computer-aided building design will enable designers to improve the energy performance in buildings, through a more appropriate design which will be better structured, will learn from previously accumulated knowledge (e.g., heuristics, databases), and will use new methods for the generation and evaluation of the design alternatives.

Well insulated walls of residences experience temperature depression in their outer layers during cold weather, causing moisture to condense on the surfaces. A predictive model capable of identifying the conditions that potentially lead to condensation or high moisture levels has been developed. The model utilized includes both moisture storage and distribution effects by utilizing the general form of the thermal energy and moisture conservation equations for each layer of a wall of typical residential construction, utilizing materials such as wood siding, insulation, and gypsum board.

SIMULAR AIR is a computer code for calculating the three dimensional transient indoor air flow using a k,e-turbulence model. It solves the nonlinear partial differential equations for momentum, energy, continuity, turbulence and air purity by an implicit time marching technique. The equations are modeled by a finite volume procedure. The model handles a variety of flow, temperature and heat flux boundary conditions including prescribed inflows and outflows. All boundary conditions can be defined time dependent.

The rapid development in the thermal energy modelling requirements for buildings, marked by the need to integrate many phenomena, has led the Applications de l'Electricit department at Electricit de France to develop a general energy simulation tool called CLIM 2000. Beyond the production of the software, our approach is to provide the specialists in the 7arious fields involved in the creation of the model library, with common formalisation rules ensuring clear and unambiguous expression of their work.To do this, we have drawn up a method based on a thermodynamic approach to the phenomena.

The technique of field modelling is applied to predict the indoor air movement and convective heat transfer induced by thermal sources in big enclosures. This is achieved by solving a system of partial differential equations describing the conservation of momentum, enthaply and mass. The k-e model is used to describe the turbulent effect. The equations are discretized using finite difference method and solved by the Semi-Implict-Method-for Pressure-Linked-Equations-Revised (SIMPLER) scheme.

The need for increasingly sharp modelling of building energy behaviour allowing comfort to be evaluated within a heated, ventilated dwelling room leads Electricite De France ADE Department to develop an air interior movement simulation model. This is a simplified modelling which it could be possible to integrate into a global building science-of-heat software programme (CLIM2000). The design principle is the division of the air volume of the room into areas for wich mass and energy balances are computed.

The "object oriented programming" and model reduction tniques give some new possibilities to develop computer tools. It is now possible to design a building on the computer, using computer objects corresponding to architectural concepts (materials, walls, windows .... ). Representing the building as a structure of objects is an approach which is particularly adapted to a thermal analysis and a comparison of designs, possibly with the help of an expert interface.

This paper describes two simulation software packages which permit building designers to understand how buildings will perform: the ESP building energy simulation system and the ARIA Computational Fluid Dynamics (CFD) air distribution simulation system. One of the major problems with CFD code is the specification of boundary conditions for the problem. ESP can provide the boundary conditions information for the CFD airflow, simulation. Two brief case studies are presented which illustrate the ability to provide the boundary conditions for the CFD problem from ESP.