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Tesi etd-09182016-210106


Tipo di tesi
Tesi di laurea magistrale
Autore
ERRANTE, PAOLO
Indirizzo email
errante.paolo@gmail.com
URN
etd-09182016-210106
Titolo
LARGE EDDY SIMULATION ANALYSIS OF FLUID JETS IN CROSS FLOW
Dipartimento
INGEGNERIA DELL'ENERGIA, DEI SISTEMI, DEL TERRITORIO E DELLE COSTRUZIONI
Corso di studi
INGEGNERIA ENERGETICA
Relatori
relatore Prof. Ambrosini, Walter
relatore Bieder, Ulrich
Parole chiave
  • cfd
  • crossflow
  • jet
  • les
  • turbulence
Data inizio appello
06/10/2016
Consultabilità
Completa
Riassunto
This work has been carried out at the "Laboratoire de Modélisation et Simulation en mécanique des Fluides" of CEA during a stage of 6 months. The main subject of this work involves jets in cross flow, which are of fundamental industrial importance and play an important role in the validation of turbulence models. Two jet configurations are investigated with the TrioCFD code:

• a tee junction of circular tubes where a hot jet discharges into a cold main flow.
• a rectangular channel discharging a jet marked by a scalar into a main channel flow.

The tee-junction configuration is very important for the phenomena of thermal fatigue. The OECD/NEA benchmark on the Vattenfall tee junction flow is analyzed. This test case is selected because, beside the experimental results, various calculations with several turbulence modeling approaches have been published. A Large Eddie Simulation (LES) modeling and calculation strategy is developed and validated on these data for jets in crossflow under thermal fatigue conditions. The rectangular jet configuration is important for basic physical understanding and modeling and has been analysed experimentally at CEA by previous studies. Such work was focused on the turbulent mixing between a rectangular channel flow with grid turbulence exiting a heated jet into a confined grid turbulent crossflow, with both kinematic and passive scalar high quality measurements in order to characterize its statistical properties (energy spectra, Reynolds stresses anisotropy and PdF). These experiments are analyzed for the first time with LES by applying the strategy developed for the first configuration. The turbulent inlet boundary conditions are well controlled in both experiment and calculation (grid turbulence). Structured and unstructured grids are used to predict the measured mean values and turbulent fluctuations (velocity and scalars) as well as the Reynolds stresses. The activities aimed also to test the capabilities of the TrioCFD code results through the inspection of their agreement with the experimental datas obtained for T-junctions mixing ducts for a preliminary analysis of TrioCFD performances and to get a balanced compliance of the code’s capabilities.
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