Malaysian Journal of Mathematical Sciences, June 2026, Vol. 20, No. 2
Thermosolutal Mixed Convection in Vertical Pipe under Chemical Reaction and Thermal Radiation
Kapoor, S., Sahoo, S.
Corresponding Email: siprarani_rs@utkaluniversity.ac.in
Received date: 9 April 2025
Accepted date: 30 September 2025
Abstract:
The present study numerically investigates the influence of thermal radiation and chemical reaction on thermosolutal mixed convection in a vertical pipe embedded in a porous medium, focusing on air water systems, which are directly applicable in technologies such as humidification-dehumidification desalination units and industrial cooling towers. The flow dynamics are modeled using the non Darcy Brinkman Forchheimer (NDBF) extended framework. The flow is driven by a combination of buoyancy forces arising from temperature and solute concentration gradients, along with an external pressure gradient. The governing coupled differential equations are solved using the Chebyshev spectral collocation method for high accuracy and spectral convergence. The results demonstrate that both the thermal radiation parameter (R) and chemical reaction parameter γ significantly affect the velocity, temperature, and concentration profile of an air-water system. According to our findings, 'R' has a substantial effect on the instability of the fluid flow mechanism. In a Darcy porous media, where the Darcy number ranges from 10-5 to 10-2, the Prandtl number is taken as Pr=0.71 for air and is Pr=7 for water, it has been observed that the point of inflection arises faster in radiative flow than in non radiative flow with change of radiation parameter from 1 to 3 and subsequently to 5. The radiation parameter (R) leads to a decrease in temperature profile due to enhanced radiative heat loss, while it causes an increase in concentration profile. Additionally, as the chemical reaction parameter increases, the concentration profile diminishes due to species consumption. A similar suppressive effect on concentration is observed with higher Schmidt number (Sc), which indicates reduced mass diffusivity.
Keywords: thermosolutal mixed convection; porous medium; pipe flow; thermal radiation; chemical reaction; spectral collocation method.
