The objective of this study is to compare the performance of different k-ε models, i.e. the Standard k-ε, the Renormalization Group (RNG) k-ε, and the Realizable k-ε, with a two-layer model for the prediction of the mean velocity field and the temperature pattern from a newly designed impinging jet supply device for ventilation of an office room. The numerical predictions are validated against ...

The purpose of this paper is to evaluate the effects of a building parameter, namely ceiling configuration, on indoor natural ventilation. The computational fluid dynamics (CFD) code Phoenics was used with the RNG k-ε turbulence model to study wind motion and ventilation flow rates inside the building. All the CFD boundary conditions were described. The simulation results were first validated b...

The Fuzzy C-means (FCM) method with Fourier coefficient based distance was firstly used to construct the vortex features and analyze large-scale unsteady flow pattern around building by transient ensemble velocity magnitude Q criterion value. performance of Reynolds-averaged Navier-Stokes (URANS) turbulence models, including Standardk−εmodel, Realizablek−ε, Renormalization Group (RNG) theoryk−ε...

In this research, the performance of nonlinear k-ε turbulence model in resolving the time delay between mean flow changes and its proportionate turbulent dissipation rate adjustment was investigated. For this purpose, the ability of Launder-Spalding linear, Suga non-linear, Yakhot RNG and Rietz modified RNG k-ε models are compared in the estimation of axial mean velocity profile and turbulent i...

We call a distribution on n–bit strings (ε, e)–locally random, if for every choice of e ≤ n positions the induced distribution on e–bit strings is in the L1–norm at most ε away from the uniform distribution on e–bit strings. We establish local randomness in polynomial random number generators (RNG) that are candidate one–way functions. Let N be a squarefree integer and let f1, . . . , f` be pol...