Experimental and numerical simulation study for natural convection heat
transfer formed by uniformly heated inclined elliptical cylinder concentrically
located in an enclosed square cylinder subjected to the ambient have been
investigated. Experiments have been carried out for Rayliegh number ranges from
0.9×106 to 3.3×106. The enclosure angles of inclination are f =0o (horizontal), 45o
(inclined), and 90o (vertical), and for axis ratio of elliptic cylinder
(minor/major=b/c) of 1:2, while the dimensions of outer square cylinder was
0.5×0.5×2 m. A numerical simulation was conducted by using commercial
Fluent CFD code to investigate the steady laminar natural convective heat
transfer for air between a heated elliptic cylinder and its square enclosure. It
covered a range of hydraulic radius ratios (HRR) of 1.97, 2.62, and 3.93 and
for orientation angles j = 0o (the major axis is vertical), 30o, 45o. Two
values of Rayligh number were taken: 0.9×106 and 3.3×106. The experimental
results showed that the heat transfer process improves as Rayliegh number
increases and is better in f =0o than other angles of inclination at the same
heat input. Theoretical results showed that the HRR, Rayligh number, and
angle of orientation have significant effect on the physical behavior of
stremlines and isotherms inside the equivalent annular gap.