Enhanced thermal performance and entropy generation analysis in a novel cavity design with circular cylinder

Abstract

Analyzing fluid dynamics and heat transfer holds significant importance in the design and enhancement of engineering systems. The current investigation utilizes the finite element method to explore natural convection and heat transfer intricacies within a novel cavity containing an inner circular cylinder under steady and laminar flow conditions. The principal aim of this study is to assess the impact of Rayleigh number (Ra), Bejan number (Be), and the presence of adiabatic, hot, and cold cylinders on heat transfer, entropy generation, and fluid flow. The range of Ra considered in this investigation spans from 103 to 106, while the Prandtl number for the air is fixed at 0.71. The findings illustrate that the presence of a cylinder leads to higher Be as Ra increase, compared to scenarios where no cylinder is present. This observation suggests that buoyancy forces dominate in the absence of a cylinder, resulting in significantly enhanced convective heat transfer efficiency. However, the presence of a heated cylinder within the tooth‐shaped cavity exerts a substantial influence on the overall thermal performance of the system. Notably, the average Nusselt Number (Nu) experiences a remarkable increase of 41.97% under the influence of a heated cylinder, when compared to situations where a cold cylinder is present. This elevated average Nu signifies improved heat transfer characteristics, ultimately resulting in an overall improvement in the thermal system's efficiency.

Thermal performance investigation of N‐shape double‐pipe heat exchanger using Al2O3, TiO2, and Fe3O4‐based nanofluids

“…Azeez et al 27 conducted a numerical analysis on a hybrid nanofluid consisting of 4% volume fraction AlN-water in a four-channel laminar FC flow heat exchanger, and observed a 30% improvement in HT in the trapezoidal channel compared to water. Moreover, further investigation on the subject matter can be located in Abay et al 28 and Saha et al 29 Upon reviewing existing literature, it was noted that there is limited reporting on the heat transfer coefficients, as well as the effectiveness and thermal performances of an N-shape double-pipe heat exchanger employing various nanofluid compositions (Al 2 O 3 , TiO 2 , and Fe 3 O 4 ). This study employs COMSOL Multiphysics to assess the thermophysical properties and performance of an N-shape double-pipe heat exchanger.…”

Heat transfer assessment incorporated with entropy generation within a curved corner structure enclosing a cold domain

“…Some relevant literature can be found in many studies. [9][10][11][12][13][14][15] The research by Natarajan et al 16 focused on the NC flow within a trapezoidal cavity. They noted that the total HT rate at the lower wall is notably higher when the left wall is subjected to linear heating while the right wall is actively cooled.…”