The computation of turbulent natural convection flows - Turbulence ...

Chapter 9
Conclusions and Future Works
9.1 Conclusions
The research presented in this thesis has followed two main objectives. The
first objective is to find how effective is the AWF, which has been recently de-
veloped in UMIST and then the University of Manchester, in the computation
of buoyancy-induced flows. The second objective is to test different models
for the approximation of turbulent stresses and turbulent heat fluxes for simu-
lation of buoyancy-driven flows. Once these two objective were achieved, an
appropriate modelling strategy was chosen to simulate buoyant flow in an an-
nular horizontal penetration, with a cold inner core. Therefore, five test cases
have been selected to cover a wide variety of buoyancy-induced flows. The
first set of test cases was of tall cavities with different angles of inclination
whose two opposite long sides are maintained at different temperatures. The
angles of inclination ranged from moderate angles of60 ◦ , with both stable and
unstable heating configurations, to high inclination angles of 5 ◦ stable and 15 ◦
stable and unstable. In summary, the cases examined are:
• 5 ◦ stable inclined tall cavity (Ra = 4.16×10 8 ).
• 15 ◦ stable inclined tall cavity (Ra = 1.6×10 6 ).
• 15 ◦ unstable inclined tall cavity (Ra = 1.6×10 6 ).
• 60 ◦ stable inclined tall cavity (Ra = 0.8×10 6 ).
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