Purpose: The purpose of this paper is to take the thermal analysis of natural convection and radiation heat transfer in fully wet porous fins. The wet porous fins taken for the analysis are straight fins in nature and wet. Their profile being straight helps heat transfer process of fins faster. The analysis is performed using the Darcy’s model to generate the heat equation to analyze the variation of convection and radiation parameters. The porous nature of the fins allows the flow to penetrate through the porous material of the fins leading to solid-fluid interface. The obtained non-dimensional ordinary differential equation involving three highly nonlinear terms are solved numerically by using spectral collocation method after which they are reduced into algebraic equations using Chebyshev polynomials. The study is analyzed using the mathematical analysis on heat equation and generating graphs for finding the parameters important to the heat transfer in the straight fins. Design/methodology/approach: This study is performed using Darcy’s model to formulate heat transfer equation. To study the thermal performance, the authors considered a finite length fin with insulated tip. The effects of the wet fin parameter m₂, porosity parameter S_h, radiation parameter G and temperature ratio C_T on the dimensionless temperature distribution and heat transfer rate are discussed. Findings: The results show that the base heat flow increases when the permeability of the medium is high and/or when the buoyancy effect induced in the fluid is strong. Research limitations/implications: The analysis is made for the Darcy’s model. Non-Darcy effects will be investigated in a future work. Practical implications: The approach is useful in enhancing heat transfer rates. Originality/value: The results of the study will be interest to the researchers of the field of heat exchanger designers.

In this article, we introduce a family of nonlinear (1+1) dimensions Schrödinger-type models with space-time fractional evolution in the sense of a conformable fractional derivative. We apply the modified Kudryashov method in context of fractional complex transformation and seek a variety of optical soliton solutions for these equations. The modified Kudryashov method is efficient and consistent for solving nonlinear space-time fractional differential equations.