Insight into Hall current impact in the hybrid squeezing nanofluid flow amid two rotating disks in a thermally stratified medium

A hybrid nanofluid is an amalgamation of two or more types of nanoparticles in a customary and possesses a variety of industrial applications. This exploration examines the blend of copper (Cu) and gold (Au), and engine oil as a hybrid nanofluid. The model considers the Hall current, Cattaneo-Christov (C-C) heat flux, thermal stratification, nonuniform heat source, and nonlinear thermal radiative effects for heat analysis. Ordinary differential equations (ODEs) are obtained through a similarity transformation scheme, and the model is visualized using a MATLAB function bvp4c. Graphs are presented to demonstrate the impact of various parameters on velocities and temperatures, and the wall drag coefficient and wall heat transfer rate are calculated and tabulated for both disks. The results show that a stronger Hall effect leads to a decrease in tangential velocity, while nonuniform heat sources increase fluid temperature. Thermal radiation and stratification have opposite effects on liquid temperature. It is interesting to note that for the radiation parameter at Rd=0.5, a higher heat transfer rate occurred at the lower disk, i.e., (Nu(1)=-3.63314) as compared to the upper disk (Nu(2)=-3.63324). Moreover, for the stratification parameter at S=0.2, it is observed that the heat transfer rate is lesser at the upper disk (Nu(2)=-3.64374) than at the lower disk (Nu(1)=-3.64274). Verification of the truthfulness of the proposed model is also included in the article.

Automated summary

This study investigates a hybrid nanofluid consisting of a mixture of copper (Cu) and gold (Au) nanoparticles with engine oil, and examines its thermal characteristics. The results show that the Hall effect and thermal radiation have opposite effects on fluid temperature, and nonuniform heat sources can increase the fluid temperature. It is observed that the lower disk has a higher heat transfer rate than the upper disk for a radiation parameter of Rd=0.5, while the upper disk has a lower heat transfer rate than the lower disk for a stratification parameter of S=0.2. The reliability of the proposed model is also verified in the article.