George Oguntala - School of Electrical Engineering and Computer Science, Faculty of Engineering and Informatics, University of Bradford,West Yorkshire, UK.
Raed Abd-Alhameed - School of Electrical Engineering and Computer Science, Faculty of Engineering and Informatics, University of Bradford,West Yorkshire, UK.
Oba Mustapha Zubair - School of Electrical Engineering and Computer Science, Faculty of Engineering and Informatics, University of Bradford,West Yorkshire, UK.
Eya Nnabuike - School of Electrical Engineering and Computer Science, Faculty of Engineering and Informatics, University of Bradford,West Yorkshire, UK.

In this work, we applied Chebychev spectral collocation method to analyze the unsteady two-dimensional flow of nanofluid in a porous channel through expanding or contracting walls with large injection or suction. The solutions are used to study the effects of various parameters on the flow of the nanofluid in the porous channel. From the analysis, It was established that increase in expansion ratio and Reynolds number decreases the axial velocity at the center of the channel during the expansion while the axial velocity increases near the surface of the channel during contraction. Moreover, it was also established that an increase in injection rate leads to a higher axial velocity near the center and the lower axial velocity near the wall. On the verification of the results, it is shown that the results obtained from Chebychev spectral collocation method are in good agreement when compared to the results obtained using other numerical methods.

Nanofluid, Porous Channel; Expanding or Contracting walls, Chebychev Spectral Collocation method