Heat transfer by initially laminar and transitional submerged, unconfined gaseous jet impingement on a plane target is analyzed numerically and additionally interpreted with the help of associated measurements. Qualitative and quantitative comparisons for three different regimes, in the transitional regime (initially laminar or low turbulence impinging jets) between Re = 1000 and 4000 are presented. A combined experimental approach has first been exploited. By using a Particle Image Velocimetry (PIV), instantaneous flow field data have been extracted and properly averaged to focus on flow field modifications at free-jet interface and along its way to impact and dispersion. Furthermore, a dimensionless local heat transfer Nu is locally assessed by micrometric measurements of ablation depth of a naphthalene film. Finally, the subject configuration has been modelled by a commercial CFD code, allowing to assess its validity. Three turbulence models have been enforced in the present paper, and complete velocity maps and local Nu distributions are presented and compared to the averaged or instantaneous experimental flow field and heat transfer data, helping ascertain on the relative merits of the adopted models.

CFD turbulent modelling of jet impingement and its validation by particle image velocimetry and mass transfer measurements

NINO, Enrico;RUOCCO, Gianpaolo
2005

Abstract

Heat transfer by initially laminar and transitional submerged, unconfined gaseous jet impingement on a plane target is analyzed numerically and additionally interpreted with the help of associated measurements. Qualitative and quantitative comparisons for three different regimes, in the transitional regime (initially laminar or low turbulence impinging jets) between Re = 1000 and 4000 are presented. A combined experimental approach has first been exploited. By using a Particle Image Velocimetry (PIV), instantaneous flow field data have been extracted and properly averaged to focus on flow field modifications at free-jet interface and along its way to impact and dispersion. Furthermore, a dimensionless local heat transfer Nu is locally assessed by micrometric measurements of ablation depth of a naphthalene film. Finally, the subject configuration has been modelled by a commercial CFD code, allowing to assess its validity. Three turbulence models have been enforced in the present paper, and complete velocity maps and local Nu distributions are presented and compared to the averaged or instantaneous experimental flow field and heat transfer data, helping ascertain on the relative merits of the adopted models.
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11563/4661
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