High-cycle thermal fatigue in mixing tees: new large-eddy simulations validated against new data obtained by PIV in the Vattenfall experiment
2009 (English)In: Proceedings of the 17th International Conference on Nuclear Engineering - 2009: presented at 17th International Conference on Nuclear Engineering, July 12 - 16, 2009, Brussels, Belgium, New York: American Society of Mechanical Engineers , 2009, 775-785 p.Conference paper (Refereed)
New data was obtained for a previously studied T-junction experimental setup  for a range of flow ratios between hot and cold flows in order to validate new Large Eddy Simulations (LES). The instantaneous velocity field downstream of the T-junction was measured with two-component Particle Image Velocimetry (PIV) in several horizontal and vertical planes at the centre line downstream of the T-junction. The generated PIV database enables a thorough validation of CFD turbulence statistics. The turbulence statistics are shown to be well predicted despite the fact that the mesh in the LES is rather coarse. By usage of time resolved PIV the temporal evolution of the predominant low frequent large-scale structures, responsible for much of the mixing and the high amplitude temperature fluctuations on the walls, were captured. Those structures are, however, weaker in LES than in PIV, being in line with the fact that the wake region behind the penetrating vertical hot jet is underpredicted in LES. Tests regarding the influence of the LES-results to the shape of the inlet boundary conditions (developed or flat symmetric mean-velocity profiles) were carried out and the sensitivity in the results was shown to be small. Furthermore, the results show good agreement with the experimental data independent of the flow ratio between the hot and the cold flows.
Place, publisher, year, edition, pages
New York: American Society of Mechanical Engineers , 2009. 775-785 p.
Engineering mechanics - Fluid mechanics
Teknisk mekanik - Strömningsmekanik
Research subject Fluid Mechanics
IdentifiersURN: urn:nbn:se:ltu:diva-40277DOI: 10.1115/ICONE17-75962Local ID: f59fdf10-8e1b-11de-8da0-000ea68e967bISBN: 978-0-7918-3852-5OAI: oai:DiVA.org:ltu-40277DiVA: diva2:1013799
International Conference on Nuclear Engineering : 12/07/2009 - 16/07/2009
Godkänd; 2009; 20090821 (torgre)2016-10-032016-10-032016-10-19Bibliographically approved