Laminar flow and heat transfer of nanofluid between contracting and rotating disks by least square method

In this study, asymmetric laminar flow and heat transfer of nanofluid between contracting rotating disks are investigated. The fluids in the channel are water containing different nanoparticles Cu, Ag and Al2O3. The effective thermal conductivity and viscosity of nanofluid are calculated by the Chon and Brinkman models, respectively. The governing equations are solved via the fourth-order Runge–Kutta–Fehlberg method (NUM) and least square method (LSM). The effects of the nanoparticle volume fraction, rotational Reynolds number, injection Reynolds number, expansion ratio and s on flow and heat transfer are considered. The results show that as s increases temperature profile increases and the point of maximum radial velocity is shifted towards the middle of the two disks. Also the results indicated that temperature profile becomes more flat near the middle of two disks with the increase of injection but opposite trend is observed with increase of expansion ratio.