LAUSR

This article examines the heat and mass transfer capabilities of a constitutive model in a thermally evolving steady laminar Jeffery–Hamel flow through a convergent-plate channel, including streamwise conduction with step changes in uniform wall temperature. A Jeffery–Hamel problem with a simple shear flow is used to undertake a comparative computational analysis of the thermal behavior of a viscoelastic fluid subjected to autocatalytic processes. The flow is tracked in a purely radial orientation with the deployment of coupled stresses in momentum conservation. The computational solutions for the flow, temperature and concentration distribution, and heat and mass transfer coefficient of a viscoelastic fluid obeying the complex Oldroyd-B constitutive equation in laminar converging channel flows are established. The analysis of the impacts of the thermal radiation, the heat source, and the chemical reaction as an autocatalytic process is included in the model, which is valid for fully developed thermal and hydrodynamic flow conditions with a constant heat and mass flux imposed at the wall. In the diverging part of the channel, where vortex compression is the predominant flow topology, there exist patches of local flow compression. On the flow field, the modified relaxation and retardation parameters show an opposing behavior. An Oldroyd-B fluid exhibits higher interactions with nearby vortices in the divergent channel, allowing a complex flow structure. The viscoelastic characteristics are anticipated to change the homogeneous–heterogeneous reaction transport processes, offering tremendous potential for applications in associated sectors. The deceleration flow in the diverging channel and the acceleration flow in the converging channel augment the average Nusselt numbers.