Convective thermal fluxes in unsteady non-homogeneous flows

In this paper we describe a novel experimental apparatus consisting of a thermoelectric driven heating and cooling device that could be used in didactic laboratories and research. Is possible to model common environmental flows by means of convective cooling and/or heating. We describe here a four cell device, in a 3D enclosure, but furthermore, it is possible to generate a convective flow of complex profiles using an array of thermoelectric devices (Peltier/Seebeck cells) controlled by a thermal proportional-integral-derivative controller generating a multisource buoyant flux. When convective heating and cooling takes place the combination of internal waves and buoyant turbulence is much more complicated if the Rayleigh and Reynolds numbers are high in order to study entrainment and mixing. The experiments made by our thermoelectric driven device could be used to analyze complex mixing, in either low or high Prandtl numbers, using scalar or heat transport in different liquids. From the varied experiments carried out with our device, we can compute and visualize the fields of velocity, vorticity, density and their gradients, here just a few configurations and the corresponding flows will be shown.This work was partially supported by the company BEROTZA S.L. under Grant No. UPC-BEROTZA-2014-0880 We would also like to thank FLUMEN-UPC and ERCOFTAC and the PELNoHT for travel support for J.T.. Technology Transfer Centre of Technical University of Catalonia (CTT-UPC) grant supported the implementation and analyses of the experiments. Sincere gratitude is extended to Dr. H. Takeda and Masao Kuramitsu from Hokaido Univ.Peer ReviewedPostprint (author's final draft

Mixing and entrainment in convective flows, jets and grid turbulence

Invited Presentation at the Lomonosov University in MoscowNew industrial and didactic flow solutions based on new flow concepts are needed to meet the unprecedented requirements set by the dramatically increasing energy needs, the use of Thermoelectric didactive devices are neded for better environmental and industrial performance. We need improvements to existing solutions, such as better convective control with radical new developments thanks to thermoelectricity coupled with fluid dynamics descriptors such as PIV. also energy savings and reduction of adverse environmental impacts can come from multifractal concepts. The development of new flows both numerically and experimentally are important for solutions with fully resolved simulations because existing turbulence models cannot be applied indiscriminately on many untested new flow ideas. One very recent example is the turbulent flows generated by fractal grids. Fractal grids are made from a structure, such as a square, repeated at different scales that allow higher mixing efficiencies.Preprin

Mixing and entrainment in convective flows, jets and grid turbulence

Invited Presentation at the Lomonosov University in MoscowNew industrial and didactic flow solutions based on new flow concepts are needed to meet the unprecedented requirements set by the dramatically increasing energy needs, the use of Thermoelectric didactive devices are neded for better environmental and industrial performance. We need improvements to existing solutions, such as better convective control with radical new developments thanks to thermoelectricity coupled with fluid dynamics descriptors such as PIV. also energy savings and reduction of adverse environmental impacts can come from multifractal concepts. The development of new flows both numerically and experimentally are important for solutions with fully resolved simulations because existing turbulence models cannot be applied indiscriminately on many untested new flow ideas. One very recent example is the turbulent flows generated by fractal grids. Fractal grids are made from a structure, such as a square, repeated at different scales that allow higher mixing efficiencies