TY - JOUR
TI - The unsteady liquid film flow of the carbon nanotubes engine oil nanofluid over a non-linear radially extending surface
AU - Alzahrani Abdullah K
AU - Ullah Malik Zaka
AU - Gul Taza
AU - Baleanu Dumitru
JN - Thermal Science
PY - 2020
VL - 24
IS - 2
SP - 951
EP - 963
PT - Article
AB - The enhancement of heat transfer through carbon material is the objective of  this study. The renowned class of carbon identified as SWCNTs (single walled  carbon nanotubes) and MWCNTs (multi walled carbon nanotubes) nanofluid flow  over a nonlinear and unstable surface has been explored. The thermophysical  properties of the two sorts of CNTs have been implemented from the  experimental outputs in the existent literature using engine oil as a base  fluid. The viscous dissipation term has also been included in the energy  equation to improve the heat transfer rate. The thickness of the nanofluid  thin layer is kept variable under the influence of the unstable and  nonlinear stretching of the disk. The elementary governing equations have  been transformed into coupled nonlinear differential equations. The problem  solution is achieved through BVP 2.0 package of the OHAM (Optimal Homotopy  Analysis Method). The square residual error for the momentum and thermal  boundary layers up to the 20th order approximations have been obtained. The  numerical ND-Solve method has been used to validate the OHAM results. The  impact of the model parameters versus velocity field and temperature  distribution have been shown through graphs and tables. The impact of the  physical parameters on the temperature profile and velocity, pitch for both  MWCNTs and SWCNTs is gained in the range of 0 ≤ Φ ≤ 4%. From the obtained results it  is observed that the SWCNTs nanofluids are more efficient to improve the  heat transfer phenomena as compared to the MWCNTs.