On the selection of a turbulence model for the simulation of steam ejectors using CFD

• Type: Article in International Scientific Journal
• Date: 2017-09-01

Authors

Szabolcs Varga (Author) FEUP; João Soares (Author) FEUP; Rafael Lima (Author) Other; Armando C. Oliveira (Author) FEUP

Journal

Title: International Journal of Low Carbon Technologies

Vol. 12

Pages: 233-243

ISSN: 1748-1317

Publisher: Oxford University Press

Indexing

ISI Web of Knowledge - 17 Citations

ISI Web of Science

Scopus - 19 Citations

Scientific classification

CORDIS: Technological sciences > Engineering

FOS: Engineering and technology > Mechanical engineering

Other information

Authenticus ID: P-00M-ZJF

DOI: 10.1093/ijlct/ctx007

Abstract (EN): Computational fluid dynamic tools have been widely used for the design and improvement of ejectors for cooling and other engineering applications over the last two decades. Most published works are based on the solution of the compressible RANS equations using commercially available codes. These codes provide a number of different turbulence models; however, very little information is available on which of these models are the most adequate to simulate ejector flow. Thus, the primary objective of this work is to assist researchers in the selection of a suitable turbulence model for the assessment of ejector cooling systems. Six turbulence models (standard k-epsilon, RNG k-epsilon, Realisable k-epsilon, standard k-omega, SST k-omega and Transition SST) are evaluated by comparing global performance indicators (coefficient of performance (COP) and critical back pressure) to experimental data obtained under a relatively wide range of operating conditions. Results clearly indicate that the Transition SST model predicts more accurately both the COP and the critical back pressure, with an average relative error of 4 and 1.4%, respectively, while the standard k-omega performs the poorest. By changing the model constants, from default to previously published values, in the standard k-epsilon model significantly improves COP predictions, only when the ejector operates in double-choking mode.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 11