Perturbation of the input data of models used for the prediction of turbulent air flow in an enclosure
- Institut National des Sciences Appliquees de Lyon, Villeurbanne (France). Centre de Thermique
- Univ. de La Rochelle (France). Lab. d`Etude des Phenomenes de Transfert Appliques au Batiment (LEPTAB)
The aim of this article is to put forward an economical method for the determination of the uncertainty domain of the numerical results compared with a computational fluid dynamics (CFD) code due to data uncertainties. In the first part of the study, the authors compare two methods of determining the domain of uncertainty: the quasi-Monte Carlo (QMC) method, and the finite-differences differential analysis (FDDA) method. This comparison is based on the two-dimensional modeling of laminar air flow in natural convection, in a small, thermally driven enclosure. The FDDA method is shown to be much more economical, in terms of computing time, than the QMC method. In the second part of the study, the authors look at a more realistic case, namely, that of the isothermal ventilated room of a building. In this second part of the study, the turbulent airflow in a two-dimensional ventilated enclosure is calculated with a {kappa}-{epsilon} model without wall functions. Two inlet velocity profiles are modeled, one plane and one parabolic. The FDDA is used to calculate the uncertainty domains of the velocity magnitude, the turbulent kinetic energy, the dissipation rate of the turbulent kinetic energy, and the turbulent viscosity. This method has already been validated by a number of studies that set it up in comparison with the reference QMC method. In the present case, while the computed uncertainty intervals were quite small in the main flow ({+-}5%), they were high at certain points in the room ({+-}60%), which suggests that either the theoretical or the numerical aspect of the model used for the prediction of the flows at these particular points will need to be improved.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 653471
- Journal Information:
- Numerical Heat Transfer. Part B, Fundamentals, Journal Name: Numerical Heat Transfer. Part B, Fundamentals Journal Issue: 2 Vol. 34; ISSN 1040-7790; ISSN NHBFEE
- Country of Publication:
- United States
- Language:
- English
Similar Records
Airflow and air quality in a large enclosure
An investigation of three-dimensional fires in enclosures