عنوان المقالة:الحمل المختلط في فجوة شبه منحرف تحتوي على اسطونه متحركه ومائع نانوي ومسامي Mixed convection in a trapezoidal enclosure filled with two layers of nanofluid and porous media with a rotating circular cylinder and a sinusoidal bottom wall
احمد كاظم حسين , حميد حمزة , فاروق علي , لواء القلسي
English Authors
Ahmed Kadhim Hussein , Hameed K. Hamzah , Farooq H. Ali , Lioua Kolsi
Abstract
الحمل المختلط في فجوة شبه منحرف تحتوي على اسطونه متحركه ومائع نانوي ومسامي
Abstract
The laminar two-dimensional mixed convection in a trapezoidal enclosure with a rotating inner circular cylinder and a
sinusoidal bottom wall is studied numerically. The fluid inside the enclosure is a CuO–water nanofluid layer in the top
space of it, while the bottom space includes a CuO–water nanofluid saturated with a porous medium. Both the right and left
sidewalls are assumed adiabatic, while the bottom and the top walls of the enclosure are maintained, respectively, at the hot
and cold temperatures. The dimensionless governing equations are expressed for velocity and temperature formulation and
modeled by using COMSOL code based on the Galerkin finite element method. Parametric studies on the effects of various
significant parameters such as Rayleigh number, Darcy number, the inner cylinder radius, the porous layer thickness, the
angular rotational velocity, the solid volume fraction and the number of undulations on the flow and thermal fields together
with the heat transfer rate have been performed. The highest value of the stream function for (Ra = 103 and Ra = 105) is seen
at (R = 0.2 and S = 0.2). The same thing is observed, when the bottom wall is considered wavy. For (Ra = 103 and N = 0) and
(0.5 ≤ S ≤ 0.8), it can be seen that as the inner cylinder radius increases from (R = 0.1) to (R = 0.3), the stream function values
increase continuously. It is found that the average Nusselt number increases as the Rayleigh and Darcy numbers, the solid
volume fraction, inner cylinder radius and the angular rotational velocity of the cylinder increase, while it decreases as the
porous layer thickness and the number of undulations increase. Comparisons with previously published numerical works
are performed, and good agreements between the results are observed.
الاستاذ الدكتور احمد كاظم حسين | Prof.Dr. Ahmed Kadhim Hussein | 5658