Mixed convective heat transfer across a turbulent flow over a porous wall layer - A numerical study

Thermal convection is a phenomenon seen in almost all facets of life, ranging from planetary convection to ocean currents and convection inside the Earth. The physics of thermal convection complicates when a porous wall layer is present. Flow over urban canopies, forest canopies or flow in underground aquifers are classic examples where thermal...

Turbulent Mixed Convection Heat Transfer in the Presence of Rough Walls

Nowadays, climate change and global warming phenomena are becoming more and more serious issues. In order to sustain the enormous worldwide energy demand, society consumes a high amount of fuel, resulting into the steep increase of the level of CO\textsubscript{2} in the environment. Therefore, the massive greenhouse gases emissions in the...

Numerical study of heat transfer and buoyancy effects in mixed convective turbulent pipe flow

The optimization of heat transfer in turbulent upward pipe flows is a very common problem in engineering, due to the wide range of applications. However, this set-up is usually categorised as mixed convection flow, which means that gravity plays an important role. Sometimes, it might lead to heat transfer deterioration. This research will...

Convective heat transfer in coarse-grained porous media: A numerical investigation of natural and mixed convection

Heat transfer by the motion of fluids, referred to as convective heat transfer, is ubiquitous. Convective heat transfer in enclosures packed with solid obstacles, is of great importance in various engineering and real-life applications, such as in blast furnaces, refrigeration devices, distribution transformers, nuclear waste disposal, energy...

Natural and Mixed Convection in Coarse-grained Porous Media

In the chain of steel production, the blast furnace converts iron ore into liquid iron. The hearth of the blast furnace, where the liquid metal is collected and tapped off, is filled with relatively large coke particles (D ~ 20 – 100 mm). The meandering flow of hot liquid metal in the coarse-grained porous medium in the hearth causes erosion of...

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...

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<...

A CFD study in a side heated cavity filled with coarse grained porous media

A CFD study is made to get more insight in the flow, temperature and heat distribution in a side heated cavity filled with coarse grained porous media. This was investigated for 105≤Ra≤107 and 0.01≤Ri≤100. The question is how the solid beads influence the heat transfer. It was found that the spheres dampen the flow, influence the local heat...

Large–eddy simulations of wall heat transfer and coherent structures in mixed convection over a wavy wall

In this numerical study the mixed convective flow of water over a heated wavy surface over a range of Reynolds and Richardson numbers, including transitional and turbulent flow regimes (20 ? Re ? 2000 and 0.5 ? Ri ? 5000) is investigated. A dynamic Large Eddy Simulation (LES) approach is applied where the thermal buoyancy effects are represented...