BARLETTA , A.

The fully developed mixed convection flow in a vertical circular duct is investigated analytically, under the assumption of laminar parallel flow. A wall heat flux uniform in the axial direction and dependent on the angular coordinate is considered. As a consequence, the fluid temperature is three dimensional, since it changes in the radial,...

The 2D heat transfer from offshore, completely buried pipelines is studied with reference to transient working conditions. In particular, the start-up case is considered (i.e., the case of a pipeline initially at equilibrium with the surrounding soil). Two different start-up cases are investigated: the step-rising case and the smooth-rising...

The steady-periodic heat transfer between offshore buried pipelines for the transport of hydrocarbons and their environment is investigated. This heat transfer regime occurs for shallow water buried pipelines, as a consequence of the temperature changes of the seabed during the year. First, the unsteady two dimensional conduction problem is...

Mixed convection in a vertical circular duct is studied under the assumption of fully developed, laminar and parallel flow. A nonaxisymmetric thermal boundary condition such that the duct wall is half subjected to a uniform heat flux and half adiabatic is considered. First, by neglecting the effect of viscous dissipation, the dimensionless...

The fully developed laminar mixed convection flow in a vertical tube of constant surface temperature is investigated assuming that (i) the effect of viscous dissipation is significant, (ii) the Boussinesq approximation holds, and (iii) the average flow velocity Um (as an experimentally accessible quantity) is prescribed. It is shown that under...

Steady combined forced and free convection is investigated in a vertical channel having a wall at rest and a moving wall subjected to a prescribed shear stress. The moving wall is thermally insulated, while the wall at rest is kept at a uniform temperature. The analysis deals with the fully-developed parallel flow regime. The governing...

The fully developed laminar mixed convection in a vertical circular duct is studied analytically, with reference to non-axisymmetric boundary conditions such that the fluid temperature does not change along the axial direction. The Boussinesq approximation is applied by taking the average temperature in a duct section as the reference fluid...

Fully developed parallel flow in an annular region filled with a porous medium surrounding an electric cable is investigated. The effects of buoyancy and MHD force as well as the heat generation due to Joule heating and viscous dissipation are taken into account. The mixed convection seepage flow is analyzed according to Darcy law and to...

Mixed convection Darcy flow in a vertical porous annulus around a straight electric cable is investigated. It is assumed that the flow is fully developed and parallel. Moreover, the Boussinesq approximation is used. The magnetic field with a steady electric current in the cable is radially varying according to the Biot-Savart law. Two flow...