“Smart” passive thermal insulation of confined natural convection heat transfer: An application to hollow construction blocks

Thermogravitational convection of Al2O3-H2O nanoliquid in a square chamber with intermittent blocks

“…They HFF 30,3 found that the time-averaged local Nu number rises with an addition of nano-sized particles. Idan and Feldman (2017) used the technique for the creation of "smart" passive insulated medium grounded on the statistical evaluation of the free convective thermal transmission in the case of a heterogeneous porous medium. They showed that the efficiency of the insulation of the porous material is associated with the dimension of the cylinders.…”

Life-Cycle and Hygrothermal Based Optimization of Insulation Filled Masonry Blocks

“…Nowadays, the design of new masonry blocks is still based mostly on manual drawings and despite significant progress achieved over the recent decade; the state of the art research in this area relies mostly on heuristic rather than on systematic methodology [Idan and Feldman, 2017]. The thermal performance of prototype masonry blocks is then usually tested in laboratory or evaluated by thermal simulations one by one, and then compared together to see which newly designed geometry alternative performs the best.…”

Oscillatory instability of 2D natural convection flow in a square enclosure with a tandem of vertically aligned cylinders

“…In engineering, the flow configuration under consideration is relevant to heat exchangers (Baïri et al 2014, Garoosi et al 2016, nuclear and chemical reactors (Hohnea et al 2006, Bieder et al 2015, and the cooling of electronic equipment (Peterson and Ortega 1990). Configurations with a large number of immersed bodies of different shapes and orientations are also widely used in the mesoscale analysis of natural convection flows in porous media (Martin et al 1998, Sangani and Yao 1998, Keyser et al 2006, Rochette and Clain 2006, Narvaez et al 2013 and comprise a computational test bed for minimizing convective heat fluxes through the boundaries of the enclosure as well as for the development of smart thermal insulating materials Feldman 2016, Idan andFeldman 2017) The investigation of natural convection within a cooled square enclosure containing a tandem of two hot circular cylinders of differing orientations, affected mainly by the mutual non-linear interactions of buoyancy flows induced by the two cylinders, is of mostly scientific interest. The steady and unsteady characteristics of this type of flow for a tandem of vertically aligned circular cylinders were elucidated by Park et al (2014) in terms of the spatial orientation of typical convection cells and the values of local and averaged Nu numbers as a function of the distance between the cylinders.…”