Numerical Analysis of Nanofluids in Differentially Heated Enclosure Undergoing Orthogonal Rotation

Abstract

Natural convection heat transfer in a rotating, differentially heated enclosure is studied numerically in this paper. The rotating enclosure is filled with water-Ag, water-Cu, water-Al 2 O 3 , or water-TiO 2 nanofluids. The governing equations are in velocity, pressure, and temperature formulation and solved using the staggered grid arrangement together with MAC method. The governing parameters considered are the solid volume fraction, 0.0 ≤ ≤ 0.05, and the rotational speeds, 3.5 ≤ Ω ≤ 17.5 rpm, and the centrifugal force is smaller than the Coriolis force and both forces were kept below the buoyancy force. It is found that the angular locations of the local maximums heat transfer were sensitive to rotational speeds and nanoparticles concentration. The global quantity of heat transfer rate increases about 1.5%, 1.1%, 0.8%, and 0.6% by increasing 1% of the nanoparticles Ag, Cu, Al 2 O 3 , and TiO 2 , respectively, for the considered rotational speeds.

Numerical Investigation into the Two-Phase Convective Heat Transfer within the Hold of an Oil Tanker Subjected to a Rolling Motion

“…Comparison of computed isotherms between present work (left) with Tso et al[21] (middle) and Saleh et al[22] (right) results under (a) φ = 0, Ra = 3 × 10 5 , Ω = 17.5 rpm, (b) φ = 3π/2, Ra = 3 × 105 , Ω = 15.5 rpm, and (c) φ = π, Ra = 3 × 10 5 , Ω = 17.5 rpm.…”

“…In addition, a natural convection in a rotation system with respect to a horizontal axis, which was an ideal case for the rolling motion in this research, was employed to validate the flow and heat transfer. The numerical results were compared with those calculated by Tso et al [21] (middle) and the experimental data performed by Saleh et al [22] (right), as shown in Figure 7. It was found that the numerical results agree well with the results in the literature.…”

Numerical Study on the Natural Convection of Air in a Cubic Cavity Subjected to a Yawing Motion

“…Fundamental study on the natural convection in rotation systems mainly concerned the constant-velocity rotation system, which is a special case for the harmonic rotation in this research. In these researches, the cavities rotate about either a horizontal axis [9][10][11][12][13][14][15] (orthogonal to the gravity axis) or a vertical axis [16][17][18][19]. These vertical rotations are the special cases (constant angular velocity) of yawing motion, which will be investigated in this study.…”