The focus of this thesis is on the response of separated turbulent flows to imposed unsteadiness in the form of pulsation. There are substantial modelling challenges in imputing flows exhibiting even steady separation and reattachment. Furthermore, to minimise computing times - particularly important in unsteady flows, given the requirement to perform a large number of time steps - there is a desire to use relatively simple RANS models of turbulence. However, simple linear eddy-viscosity models are known to perform badly in separated flows, hi this study refinements are introduced to both a non-linear eddy-viscosity (Craft et al; 2005) scheme and a DSM model (lacovides and Raisee; 1999) and these are shown to perform quite successfully in predicting the steady state flow and heat transfer through a sudden pipe-expansion. The main aim of current study is to then asses the performance of these models in computing three types of forced unsteady separated flows.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:492875 |
| Date | January 2008 |
| Creators | Momeni, Parham |
| Publisher | University of Manchester |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
Page generated in 0.0019 seconds