Assisting and opposing mixed convection with conjugate heat transfer in a differentially heated cavity filled with coarse-grained porous media

We report numerical simulations of assisting and opposing mixed convection in a side-heated, side-cooled cavity packed with relatively large solid spheres. The mixed convection is generated by imposing a movement on the isothermal vertical walls, either in or opposite to the direction of natural convection flow. For a fluid Prandtl number of...

Effect of packing height and location of porous media on heat transfer in a cubical cavity: Are extended Darcy simulations sufficient?

We numerically investigate natural convection in a bottom-heated top-cooled cavity, fully and partially filled with adiabatic spheres (with diameter-to-cavity-size ratio d/L=0.2) arranged in a Simple Cubic Packing (SCP) configuration. We study the influence of packing height and location of porous media. We carry out the simulations using...

Experiments on mixed convection in a vented differentially side-heated cavity filled with a coarse porous medium

This paper reports on an experimental study of mixed convection flow and heat transfer in a vented, differentially side-heated cubical cavity filled with a porous medium consisting of relatively large solid low-conductivity spheres. Rayleigh numbers and Reynolds numbers are varied over the ranges 6 × 10⁶ &lt; Ra &lt; 7 × 10<sup>7<...

Numerical analysis of natural convection in a differentially heated packed bed with non-uniform wall temperature

We report numerical simulations of natural convection and conjugate heat transfer in a differentially heated cubical cavity packed with relatively large hydrogel beads (d/L=0.2) in a Simple Cubic Packing configuration. We study the influence of a spatially non-uniform, sinusoidally varying, wall temperature on the local flow and heat transfer...

Flow and heat transfer measurements in natural convection in coarse-grained porous media

This paper reports on an experimental study of natural convection in an enclosure that is heated at the bottom and cooled at the top, filled with a packed bed of relatively large solid spheres. Nusselt numbers were measured for various sphere conductivities, spheres sizes and sphere packings for Rayleigh numbers varying between 10⁷...

Numerical analysis of natural convection with conjugate heat transfer in coarse-grained porous media

We report numerical simulations of fluid natural convection with conjugate heat transfer in a bottom-heated, top-cooled cubical cavity packed with relatively large (d/L=0.2) solid spheres in a Body Centred Tetragonal (BCT) configuration. We study largely varying solid-to-fluid thermal conductivity ratios between 0.3 and 198, for a fluid...

An experimental study of flow and heat transfer in a differentially side heated cavity filled with coarse porous media

Flow and heat transfer in a differentially side heated cubic cavity filled with relatively large solid spheres forming a coarse porous medium have been studied experimentally. Nusselt numbers were measured for Rayleigh numbers between 1.9 × 10⁷ and 1.7 × 10⁹, solid-to-fluid conductivity ratios between 0.32 and 618, and...

Analytical solutions of one-way coupled magnetohydrodynamic free surface flow

We study the flow in a layer of conductive liquid under the influence of surface tension, gravity, and Lorentz forces due to imposed potential differences and transverse magnetic fields, as a function of the Hartmann number, the Bond number, the Reynolds number, the capillary number and the height-to-width ratio A. For aspect ratios A 1 and...

Electromagnetic control of an oscillating turbulent jet in a confined cavity

Control of self-sustained jet oscillations in confined cavities is of importance for many industrial applications. It has been shown that the mechanism underlying these oscillations consists of three stages: (i) growth of the oscillation, (ii) amplitude limitation and (iii) delayed destruction of the recirculation zone bounding the jet. It has...

Dynamics of an oscillating turbulent jet in a confined cavity

We demonstrate how the self-sustained oscillation of a confined jet in a thin cavity can be quantitatively described by a zero-dimensional model of the delay differential equation type with two a priori predicted model constants. This model describes the three phases in self-sustained oscillations: (i) pressure driven growth of the oscillation, ...

Effects of electromagnetic forcing on self-sustained jet oscillations

The influence of electromagnetic forcing on self-sustained oscillations of a jet issuing from a submerged nozzle into a thin vertical cavity (width W much larger than thickness T) has been studied using particle image velocimetry. A permanent Lorentz force is produced by applying an electrical current across the width of the cavity in...

Numerical and Experimental Study of Electromagnetically Driven Vortical Flows

The paper reports on numerical and experimental investigations of electromagnetically driven vortical flows of an electrically conductive fluid in a generic setup. Two different configurations of permanent magnets are considered: a 3-magnet configuration in which the resulting Lorentz force is focused in the wall-boundary layers, and a 2-magnet...

Analysis and Modelling of Physical Transport Phenomena

These lecture notes contain the course material Advanced Physical Transport Phenomena, offered in the Master’s programme in Applied Physics at Delft University of Technology. The notes follow in part the concept and content of the book Fysische Transportverschijnselen II (in Dutch) by Hoogendoorn and Van der Meer (Delft University Press, 1991)....