Darcy-Forchheimer hybrid nanofluid flow in an asymmetric channel with an exponential heat source, variable thermal conductivity, and activation energy

Abstract

Background

Heat transfer in nanofluid flows plays a vital role in many industrial, medical, and manufacturing industries. Hybrid nanofluid (HNF) has a significant potential to enhance the thermal characteristics of several fluids employed in a wide range of thermal systems and thus uses reduced energy and provides increased sustainability. Also, the thermal conductivity of nanofluid depends on the mobility of nanoparticles and that can be improved by activation energy (AE) besides the latent micro convection. Literature reveals that the research works available on the enhanced heat transfer due to the appropriate combination of nanoparticles along with AE in an asymmetric channel is very limited.

Aim

This study aims to explore the impact of the AE and the variable thermal conductivity (VTC) on the HNF flow in an asymmetric channel with permeable walls. The effects of radiation, thermal conductivity, and exponential heat sources are also considered.

Method

An effective similarity transformation is used to convert the governing equations into a system of nonlinear ordinary differential equations (ODEs). The nonlinear ODEs with appropriate boundary conditions are solved numerically by a shooting method.

Results

The consequences of the physical parameters on the axial velocity, temperature, and species concentration are explained and are presented through graphs. In comparison to viscous fluid, the dual nanofluids have a 5.8% higher heat transfer rate with VTC parameter at the lower wall. However, the species concentration rate of HNF is 20.0% higher than that of viscous fluid with AE parameter.

Keywords:

• Activation energy
• asymmetric channel
• heat transfer
• nanofluid flow
• thermal radiation
• variable thermal conductivity

Acknowledgments

The authors thank the reviewers and the editor-in-chief for their constructive comments which led to a definite improvement in the article. The authors also thank Dr. M. Taylor for reading the manuscript for better readability and English.

Disclosure statement

No potential conflict of interest was reported by the authors.