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Wan YS Chau JL Gavriilidis A Yeung KL 《Chemical communications (Cambridge, England)》2002,(8):878-879
A zeolite-based microengineered reactor was fabricated and tested for 1-pentene epoxidation over titanium silicalite-1 (TS-1) catalyst, which has been selectively incorporated within the microreactor channel using a new synthesis procedure. 相似文献
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A. Pantokratoras 《Heat and Mass Transfer》2003,39(8-9):737-743
In all studies concerning laminar mixed convection along a vertical isothermal moving cylinder a linear relationship between
fluid density and temperature has been used and viscosity and thermal conductivity have been considered constant. However,
it is known that the density-temperature relationship for water is non-linear at low temperatures and viscosity and thermal
conductivity are functions of temperature. In this study the problem of water laminar mixed convection along a vertical isothermal
moving cylinder has been investigated in the temperarure range between 20 °C and 0 °C taking into account the temperature
dependence of μ, k and ρ. The results are obtained with the numerical solution of the boundary layer equations. The variation
of μ, k and ρ with temperature has a strong influence on mixed convection characteristics. 相似文献
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A Pantokratoras 《Heat and Mass Transfer》2005,41(12):1085-1094
The steady laminar boundary layer flow along a flat plate is studied taking into account the variation of fluid viscosity and fluid Prandtl number with temperature. In the forced convection case the plate moves with constant velocity and its temperature varies in power law with x. In the mixed convection case the plate temperature is constant and the fluid moves upwards due to an external free stream and due to buoyancy forces. The results are obtained with the direct numerical solution of the boundary layer equations. The study concerns the wall heat transfer, the wall shear stress and velocity and temperature profiles across the boundary layer. The results of the present work are different from those existing in the literature, which have been obtained with the assumption of constant Pr number. 相似文献
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The work of Mahmood and Merkin (ZAMP 39:186–203, 1988) concerns the mixed convection flow along a stationary cylinder in a
constant free stream. In the present note, we extend the above work to general situations involving a moving cylinder. 相似文献
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Bakolas Asterios Aggelakopoulou Eleni 《Journal of Thermal Analysis and Calorimetry》2019,135(6):2953-2961
Journal of Thermal Analysis and Calorimetry - In order to evaluate the pozzolanic activity of a natural pozzolan (NP) of rhyolitic composition, several pastes were prepared by mixing the pozzolan... 相似文献
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A note on mixed convection of laminar plane water plumes at temperatures around the density extremum
In all studies concerning mixed convection in plane laminar plumes a linear relationship between fluid density and temperature
has been used. However, it is known that the water density-temperature relationship is non-linear at low temperatures with
a density maximum at 3.98°C for pure water. In this note the problem of plane laminar water plume in a coflowing vertical
free stream has been investigated taking into account the non-linearity between density and temperature. This is the first
work in the literature which treats plane mixed convection plumes with nonlinear relation between density and temperature.
Both rising and descending plumes have been investigated. It was found that the ambient water temperature plays an important
role on the results. When the ambient temperature is greater than maximum density temperature (T
a > T
m), the water plume behavior is similar to that of the classical plume with linear density-temperature relationship. However,
when the ambient temperature is equal or lower than the maximum density temperature the water plume behavior is completely
different from the classical plume with linear density-temperature relationship. The centerline velocity shows a series of
maxima and minima which are produced by the combination of the nonlinear density-temperature relation and the free stream. 相似文献
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Asterios Pantokratoras 《Archive of Applied Mechanics (Ingenieur Archiv)》2009,79(5):469-478
A theoretical study of the effect of variable fluid properties on the Blasius and Sakiadis flow with uniform suction at the
asymptotic state is presented in this paper. The investigation concerns air and water taking into account the variation of
their physical properties with temperature. Velocity and temperature profiles are presented as well as values of the displacement
thickness, momentum thickness, shape factor, wall shear stress and Nusselt number for different temperatures of the plate
and the ambient fluid. It is found that the nondimensional displacement thickness, momentum thickness, shape factor, absolute
wall shear stress and Nusselt number are identical in both Blasius and Sakiadib flow at the asymptotic state for a fluid with
constant properties. The same is valid for any fluid with variable properties if the temperature boundary conditions are the
same in Blasius and Sakiadis flow. 相似文献
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All studies concerning laminar free convection along a vertical isothermal plate in water at low temperatures have been conducted assuming constant dynamic viscosity and thermal conductivity both taken at ambient or film temperature. In this study the problem has been treated taking into account the temperature dependence of all water physical properties. The results are obtained with the numerical solution of the boundary layer equations. The variation of μ and k with temperature has a small influence on wall heat transfer but a strong influence on wall shear stress. These quantities show a significant reduction at density extremum. 相似文献