http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Study of natural convection heat transfer above a horizontal heated plate using a laser specklegram technique
Heat transfer by free convection in air from an isothermal horizontal heated flat plate facing upward has been experimentally studied by using a non intrusive and accurate optical technique, Speckle photography or a specklegram technique. The local and the average heat transfer coefficients and hence the Nusselt numbers were determined in the range of Rayleigh numbers from 9 x 10' to 4 x 10'. The nature of the free convection flow over the heated surface was inferred from the local and average Nusselt numbers and the boundary layer pictures at varying Rayleigh numbers. Measurements were compared with both experimental and theoretical results. The convective heat transfer from the horizontal flat plate showed an increase with increasing "specific perimeter per unit area" or with decreasing aspect ratio of the heated surface. The critical Rayleigh number for laminar to turbulent transition for a horizontal isothermal surface has been estimated to be 3.0 x 10'. The experimental results show that the specklegram technique has a strong potential to be a new and powerful technique for the assessment of heat transfer behaviors.
"Major subject: Mechanical Engineering".