Flow simulation

While thermal simulations yield findings on expected average temperatures of room air and of room-enclosure surfaces, they do not provide data on temperature layering and on local air speeds and ventilation rates. Nor do they provide detailed information about thermal comfort levels.

Flow simulations using computational fluid dynamics (CFD) make it possible to study airflows and temperature conditions throughout complex room geometries, for specific defined parameters. In such simulations, a model of the room volume being studied is overlaid with a (virtual) cellular lattice structure. Basic equations for pressure, temperature and flow speed are solved for each cell in the structure, and then the results are studied in terms of interaction between all cells. Ideally, such calculations, via an iterative process, lead to a stable solution for all cells in the room model.

Due to the involved calculations and modeling involved in such CFD simulation, in most cases only stationary conditions can be studied; i.e. each simulation yields a result for one specific set of defined parameters. At the same time, such results can be scaled from the room dimension (room airflow) to the building-interior dimension (air throughflow within a building, from room to room, or from rooms to the facade) and to the building-exterior dimension in which the circulation around and near the structure is considered (flow in inner courtyards, across properties, and in the surrounding district).

Flow simulations are especially of use in the following ways:

  • Producing comfort-level and temperature analyses relative to room ventilation via mechanical, natural or coupled ventilation
  • Determining the effects of air throughflow in double facades
  • Analyzing the ventilation effects, on interior rooms, of atriums or conservatories
  • Studying spreading of particulates and pollutants in laboratories or in outside areas
  • Determining ventilation requirements for data centers
  • Carrying out three-dimensional thermal-bridge calculations

Flow simulations

Reference: RTL Studio (Rheinpark Metropole, Köln)

Assessment in terms of thermal comfort levels

Assessment in terms of air-temperature levels

Assessment in terms of air speeds