Thermal performance of fully wet longitudinal porous fin with temperature-dependent thermal conductivity, surface emissivity and heat transfer coefficient

Abstract

Purpose The purpose of this paper is to study the thermal behaviour of a fully wet porous fin of longitudinal profile. The significance of radiative and convective heat transfer has been scrutinised along with the simultaneous variation of surface emissivity, heat transfer coefficient and thermal conductivity with temperature. The emissivity of the surface and the thermal conductivity are considered as linear functions of the local temperature between fin and the ambient. Darcy’s model was considered to formulate the heat transfer equation. According to this, the porous fin permits the flow to penetrate through it and solid–fluid interaction occurs. Design/methodology/approach Runge–Kutta–Fehlberg fourth–fifth-order method has been used to solve the reduced non-dimensionalized ordinary differential equation involving highly nonlinear terms. Findings The impact of pertinent parameters, such as convective parameter, radiative parameter, conductivity parameter, emissivity parameter, wet porous parameter, etc., on the temperature profiles were elaborated mathematically with the plotted graphs. The heat transfer from the fin enhances with the rise in convective parameter. Originality/value The wet nature of the fin enhances heat transfer and in many practical applications the parameters, such as thermal conductivity, heat transfer coefficient as well as surface emissivity, vary with temperature. Hence, the main objective of the current study is to depict the significance of simultaneous variation in surface emissivity, heat transfer coefficient and thermal conductivity with respect to temperature under natural convection and radiation condition in a totally wetted longitudinal porous fin.

Transient thermal investigation of a fully wet porous convective–radiative rough cylindrical pin fin

“…The thermal conductivity $$k(T)$$ and convective heat transfer coefficient $$h(T)$$ of the fin are given by 8,23 $$$k(T)={k}_{a}(1+\alpha (T-{T}_{a})),$$$ $$$h(T)={h}_{a}{\left(\frac{T-{T}_{a}}{{T}_{b}-{T}_{a}}\right)}^{p}={h}_{D}{C}_{p}L{e}^{\frac{2}{3}},$$$where $${k}_{a}$$ is the thermal conductivity at temperature $${T}_{a}$$, $$\alpha $$ is the measure of thermal conductivity variation with temperature, $${h}_{a}$$ is the heat transfer coefficient at temperature $${T}_{a}$$, $${h}_{D}$$ is the uniform mass transfer coefficient, $${Le}$$ is the Lewis number, $${C}_{p}$$ is the specific heat of the ambient fluid, and $$p$$ is the exponential index.…”

“…The transient response of distinct profiles of the longitudinal fin was investigated by Pasha et al 7 by employing the semianalytical method of differential transformation. Sowmya et al 8 scrutinized the porous fin problem in the presence of fully wet conditions. It has been concluded that the porosity and wet nature of the fin enhance the rate of exchange of heat.…”

Convective-radiative moving porous fin with temperature-dependent thermal conductivity, heat transfer coefficient and wavelength-dependent surface emissivity

“…The direct technique used in the study was based on the series expansion of temperature in the mounted surface area, which required no numerical technique to find the temperature. Sowmya et al (2019) studied the performance of a fully wetted longitudinal porous fin. The conductivity and emissivity were taken as a linear function of temperature.…”

Analysis of heat transmission in convective, radiative and moving rod with thermal conductivity using meta-heuristic-driven soft computing technique

“…Heat transmission is the phenomenon used to explain heat transfer from higher temperatures toward lower concentrations (Gireesha and Sowmya 2020). In recent years, the process of heat transfer has emerged as the most important subject in the field of thermal engineering due to the prediction Responsible Editor: Mehmet Polat Saka of heat exchanger in variety of circumstances including solar collector, gas turbines, radiators in cars, and energy production (Alkam and Al-Nimr 1999;Deshamukhya et al 2018;Sowmya et al 2019;Khan et al 2021d). The heat exchangers or extended surfaces are an integral part of any device that generates heat during its working process.…”