Heat transfer in the thermal entrance region of trapezoidal microchannels is investigated for hydrodynamically fully developed, single-phase, laminar flow with no-slip conditions. Three-dimensional numerical simulations were performed using a finite-volume approach for trapezoidal channels with a wide range of aspect ratios. The sidewall angles of 54.7 and 45 are chosen to correspond to etch-re...

This article addresses the boundary layer flow and heat transfer in third grade fluid over an unsteady permeable stretching sheet. The transverse magnetic and electric fields in the momentum equations are considered. Thermal boundary layer equation includes both viscous and Ohmic dissipations. The related nonlinear partial differential system is reduced first into ordinary differential system a...

The present paper deals with the effects of Ohmic dissipative Casson fluid flow over a stretching sheet in the presence of aligned magnetic field. The present phenomenon also includes the interaction of thermal radiation and velocity slip. The governing boundary layer equations are transformed into a set of ordinary differential equations using the similarity transformations. The dimensionless ...

In the present study, an analysis is carried out to study the variable viscosity and chemical reaction effects on the flow, heat, and mass transfer characteristics in a viscous fluid over a semi-infinite vertical porous plate. The governing boundary layer equations are written into a dimensionless form by similarity transformations. The transformed coupled nonlinear ordinary differential equati...

BACKGROUND Heat transfer enhancement technology concerns with the aim of developing more efficient systems to satisfy the increasing demands of many applications in the fields of automotive, aerospace, electronic and process industry. A solution for obtaining efficient cooling systems is represented by the use of confined or unconfined impinging jets. Moreover, the possibility of increasing the...

in this work, the steady and laminar mixed convection of nanofluid in horizontal concentric annulus withrotating inner cylinder is investigated numerically. the inner and outer cylinders are kept at constanttemperature ti and to respectively, where ti>to. the annular space is filled with alumina-water nanofluid.the governing equations with the corresponded boundary conditions in the polar coord...

We present high-precision measurements of the Nusselt number N as a function of the Rayleigh number R for a cylindrical sample of water (Prandtl number sigma=4.4) of height L approximately equal to 50 cm and aspect ratio Gamma identical with D/L approximately equal to 1 (D is the diameter) for 3 x 10(9)< or =R< or =6 x 10(10). For R approximately 3 x 10(9) the data are consistent with existing ...

The main purpose of this paper is to introduce a boundary layer analysis for the fluid flow andheat transfer characteristics of an incompressible nanofluid flowing over a permeable isothermalsurface moving continuously. The resulting system of non-linear ordinary differential equations issolved numerically using the fifth–order Runge–Kutta method with shooting techniques usingMatlab and Maple s...

Purpose – The purpose of this work is to study the flow of mixed convection and mass transfer of a steady laminar boundary layer about an isothermal vertical flat plate embedded in a non-Darcian porous medium in the presence of chemical reaction and viscous dissipation effects. Design/methodology/approach – The governing partial differential equations are converted into ordinary differential eq...