ETD system

Electronic theses and dissertations repository

 

Tesi etd-09232011-113806


Thesis type
Tesi di laurea specialistica
Author
BARALE, MARCO
URN
etd-09232011-113806
Title
Investigation into Lean-Burn Combustor Thermo-acoustic Instabilities: Modelling of Entropy Convection for Low Frequency Rumble Prediction
Struttura
INGEGNERIA
Corso di studi
INGEGNERIA AEROSPAZIALE
Commissione
relatore Prof. d'Agostino, Luca
relatore Prof. Paganucci, Fabrizio
tutor Dott. Stow, Simon R.
Parole chiave
  • CFD
  • Rolls-Royce
  • rumble
  • entropy
  • lean burn
  • combustion chamber
  • combustor
  • acoustic
  • thermoacoustic
Data inizio appello
11/10/2011;
Consultabilità
parziale
Data di rilascio
11/10/2051
Riassunto analitico
New combustion methods, aimed to reduce emissions, are shown to be susceptible to instability. To reduce nitrogen oxides, the traditional diffusion flame is replaced by lean combustion, where fuel-air are partially premixed, and combustion conditions are set to keep the flame temperature cooler, producing the minimum amount of NOx. However they are more sensitive to unsteady combustion that generates acoustic waves which alter the mixture fraction; at a certain conditions the self-excited oscillations may grow showing the rumble phenomena.<br>This work has been carried on in Rolls-Royce plc, in Combustion &amp; Casings department, while a six month internship by Aerothermal Methods team. <br>The task is aimed to improve the acoustic in-house program, coming to a new entropy convection model for rumble prediction.
File