No abstract

The boundary layer flow and heat transfer of a nanofluid over a stretching sheet are numerically studied. Velocity slip is considered instead of no-slip condition at the boundary as is usually appears in the literature. The governing partial differential equations are transformed into ordinary ones using a similarity transformation, before being solved numerically. Numerical solutions of these equations are obtained using finite element method (FEM). The variations of velocity and temperature inside the boundary layer as well as the skin friction coefficient and the heat transfer rate at the surface for some values of the governing parameters, namely, the nanoparticle volume fraction and the slip parameter are presented graphically and discussed. Comparison with published results for the regular fluid is presented and it is found to be in excellent agreement.

No abstract

The influence of silicon content and solution and aging temperature on microstructure and mechanical properties, and mode of fracture of cast Al-(4-20)Si-0 . 3Mg alloys is reported. Alloys were prepared by controlled melting, casting and heat treatment. Increasing solution temperature from 450 to 550uC and aging temperature from 150 to 230uC increased the tensile strength of all the Al-Si-Mg alloys. High solution temperatures produce greater refinement and distribution of eutectic silicon grains than low temperatures. Scanning electron microscopy of tensile fracture surfaces showed that the fracture surface of specimens treated at higher solution and aging temperatures is characterised by finer, equaixed dimples than that of specimens heat treated at lower temperatures.a Al-4Si-0 . 3Mg; b Al-8Si-0 . 3Mg; c Al-12Si-0 . 3Mg; d Al-16Si-0 . 3Mg; e Al-20Si-0 . 3Mg 1 Optical micrographs of as cast alloys Dwivedi et al. Influence of silicon content and heat treatment parameters on properties of Al-Si-Mg alloys

No abstract