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Tesi etd-04052018-212617


Thesis type
Tesi di laurea magistrale
Author
CONTE, PASQUALE
URN
etd-04052018-212617
Title
Analysis of bubble dynamics and data processing in flow boiling heat transfer.
Struttura
INGEGNERIA DELL'ENERGIA, DEI SISTEMI, DEL TERRITORIO E DELLE COSTRUZIONI
Corso di studi
INGEGNERIA ENERGETICA
Commissione
relatore Prof. Ambrosini, Walter
relatore Prof. Baglietto, Emilio
correlatore Ing. Mazzocco, Thomas
correlatore Ing. Kommajosyula, Ravikishore
Parole chiave
  • image processing
  • critical heat flux
  • heat partitioning
  • heat transfer
  • bubble departure
  • flow boiling
Data inizio appello
24/04/2018;
Consultabilità
parziale
Data di rilascio
24/04/2021
Riassunto analitico
This work, as a further step in the research concerning bubble behaviour, is a continuation of a previous work made by Mazzocco et al. [2016] and is divided into two parts, referred to two different aspects of the challenges to be faced to set up boiling models for CFD codes.<br>The first part, that more closely continues the investigation leading to the model presented by Mazzocco et al. [2016], is related to boiling at low heat flux in which a single nucleation site is monitored in order to validate models for bubble departure based on force balances. The goal of this part of the work is to validate and further optimise the value of a parameter, identified as X, which includes a physical representation of the thermal conditions around the bubble and also several uncertainties appearing in the model; this goal is achieved addressing different datasets and further investigating the values of the forces acting on the bubble during its departure. This first part has produced improved numerical values with respect to ones obtained in the previous work, but it has also confirmed the previous physical observations. <br>The second part, suggested by the need to improve the predictive performance of heat partitioning models for high flux cases, represents a first step to set up an efficient Matlab script aiming to measure bubble diameters using an infrared camera and an high speed video camera. The goal is to get new data in order to improve the model while addressing high flux cases.<br>The mechanistic model resulting from this research, of which this work is only a step in a long path, will be implemented in a CFD code to improve the predictive performance of heat partitioning models. The ultimate aim of having an improved and more robust boiling heat transfer model is the prediction of critical heat flux through delivering an accurate representation of the physics at the boiling wall.
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