الفهرس | Only 14 pages are availabe for public view |
Abstract A nanofluid is a suspension of ultrafine particles with extremely high thermal conductivity in a conventional base fluid which has the potential increases the heat transfer characteristics of the original fluid, also defined as a colloidal suspension of particles in a base fluid, where the particles have a characteristic length of less than 100 nm. Investigation were conducted to determine the qualification of nano fluids for flow forced convection heat transfer Recently, newly developed material nanometer-sized particles have been utilized in suspension in conventional heat transfer fluids The present thesis is concerned with forced convection heat transfer in flow with nanofluid. The Investigation were conducted in four different models of tubes with L/D=10,20,30, 40 with constant heat flux with varying from 200 w/m2 to 1000 w/m2 and with different nano fluid concentration from 1% to 6% using blood as non- Newtonian fluid and gold as nano particles at range of Reynolds number from 4000 to 15000. The results showed that the heat transfer coefficient enhanced with increasing the nanoparticle concentration and Reynolds number. In addition, heat transfer coefficient and Nu number of non-Newtonian nanofluid increased when concentration of gold-blood solution increased. Also Convective heat transfer coefficient and Nusselt number of nanofluid are remarkably higher than those of the base fluid. These enhancements of nanofluid are directly proportional to the particle concentration and Reynolds number. By applying the simulation results, an equation for Nu number as a function of Reynolds number, diameter, heat flux and nanoparticles concentration was correlated. The correlation had good agreement with the simulation data. |