Analysis of Heat Transfer for the Copper–Water Nanofluid Flow through a Uniform Porous Medium Generated by a Rotating Rigid Disk

This study theoretically investigates the temperature and velocity spatial distributions in
the flow of a copper–water nanofluid induced by a rotating rigid disk in a porous medium. Unlike
previous work on similar systems, we assume that the disk surface is well polished (coated); therefore,
there are velocity and temperature slips between the nanofluid and the disk surface. The importance
of considering slip conditions in modeling nanofluids comes from practical applications
where rotating parts of machines may be coated. Additionally, this study examines the influence of
heat generation on the temperature distribution within the flow. By transforming the original Navier–
Stokes partial differential equations (PDEs) into a system of ordinary differential equations
(ODEs), numerical solutions are obtained. The boundary conditions for velocity and temperature
slips are formulated using the effective viscosity and thermal conductivity of the copper–water
nanofluid. The dependence of the velocity and temperature fields in the nanofluid flow on key parameters
is investigated. The major findings of the study are that the nanoparticle volume fraction
significantly impacts the temperature distribution, particularly in the presence of a heat source. Furthermore,
polishing the disk surface enhances velocity slips, reducing stresses at the disk surface,
while a pronounced velocity slip leads to distinct changes in the radial, azimuthal, and axial velocity
components. The study highlights the influence of slip conditions on fluid velocity as compared to
previously considered non‐slip conditions. This suggests that accounting for slip conditions for
coated rotating disks would yield more accurate predictions in assessing heat transfer, which would
be potentially important for the practical design of various devices using nanofluids.