Entropy Generation in Thermal Radiative Loading of Structures with Distinct Heaters

Abstract

Thermal loading by radiant heaters is used in building heating and hot structure design applications. In this research, characteristics of the thermal radiative heating of an enclosure by a distinct heater are investigated from the second law of thermodynamics point of view. The governing equations of conservation of mass, momentum, and energy (fluid and solid) are solved by the finite volume method and the semi-implicit method for pressure linked equations (SIMPLE) algorithm. Radiant heaters are modeled by constant heat flux elements, and the lower wall is held at a constant temperature while the other boundaries are adiabatic. The thermal conductivity and viscosity of the fluid are temperature-dependent, which leads to complex partial differential equations with nonlinear coefficients. The parameter study is done based on the amount of thermal load (presented by heating number) as well as geometrical configuration parameters, such as the aspect ratio of the enclosure and the radiant heater number. The results present the effect of thermal and geometrical parameters on entropy generation and the distribution field. Furthermore, the effect of thermal radiative heating on both of the components of entropy generation (viscous dissipation and heat dissipation) is investigated.

Effects of Radiative Electro-Magnetohydrodynamics Diminishing Internal Energy of Pressure-Driven Flow of Titanium Dioxide-Water Nanofluid due to Entropy Generation

“…They perceived that entropy generation near the channel wall rapidly increased with the increase of the joule heating parameter. A few remarkable contributions on entropy generation with diverse studies can be explored in References [22][23][24][25][26][27][28].The existing literature firmly endorses that the effective influences of electro-magnetohydrodynamics (EMHD) and entropy generation with nanoparticles through a wavy channel on Poiseuille flow synthesis, are yet not to be addressed. In addition, what made this investigation more fruitful was to observe the simultaneous application of electro-hydrodynamics (EHD) and thermal radiation.…”

“…They perceived that entropy generation near the channel wall rapidly increased with the increase of the joule heating parameter. A few remarkable contributions on entropy generation with diverse studies can be explored in References [22][23][24][25][26][27][28].…”

Optimal Design of Thermal Radiative Heating of Horizontal Thin Plates Using the Entropy Generation Minimization Method

“…Hence, the greatest contribution of the generated entropy would be based on the thermal radiation heat transfer mode and the natural convection heat transfer mode. It was also shown in [22] that the total entropy generation rate per volume throughout the open cavity is increased for N r higher than one (for lower values where the heat conduction is dominant, it is almost constant), but these conditions are not true in all of the cases. Proof of this is plotted in Figure 11, which demonstrates the role of heat source number and heating ratio in entropy generation, while the total rate of entropy generation per volume surface is schemed against the heating ratio for various numbers of heat sources in the open cavity.…”

“…Moreover, surface thermal radiation can increase the amount of entropy generation by as much as five times [21]. Recently, the entropy generation in the thermal radiative loading of structures with distinct heaters has been studied by Jamalabadi et al [22]. As shown in most of the cavity (other than zone around the lamps), entropy generation is caused by fluid motion rather than heat transfer.…”

“…Based on the study conducted by Jamalabadi et al [22], a code was developed using finite volume method with SIMPLE algorithm that solves the governing equation of motion. The code was first validated by comparing the results to those of the benchmark solution from the natural convection of air in a square cavity [23] and also a simulation of a natural convection investigation with a high Rayleigh number in a square cavity [24].…”