Paper Conference

Proceedings of BSO Conference 2012: 1st Conference of IBPSA-England


CFD-Free, Efficient, Micro Indoor Climate Prediction in Buildings

Lars Eriksson, Grigori Grozman, Pavel Grozman, Per Sahlin, Mette Havgaard Vorre, Lars Ålenius

Abstract: Today, the only accessible simulation method to gain insight into more detailed room thermal comfort is to use CFD. Unfortunately, CFD is much too cumbersome to apply on a routine basis. To gain information that represents longer periods (such as years) and that includes radiation and thermal mass effects, execution time becomes prohibitively long. Another fundamental problem with CFD is that significant work must be spent on the development of a suitable computational grid. This paper investigates the possibility of obtaining sufficiently accurate design information by improving the accuracy of a traditional well-mixed building simulation zone model. A Modelica zone model has been developed that is enhanced by three means: (1) view factors are computed for arbitrary, also self-obstructing, zone geometries, (2) vertical gradients are computed by a multi-node 1D model, and (3) jet and plume flow element theory is applied to track individual jets from salient heat or mass sources. The main design decisions are presented along with some preliminary computational results.
Pages: 149 - 156