On the role of secondary motions in turbulent square duct flow

We use a direct numerical simulations (DNS) database for turbulent flow in a square duct up to bulk Reynolds number \Rey_b=40000, to quantitatively analyze the role of secondary motions on the mean flow structure. For that purpose we derive a generalized form of the identity of Fukagata, Iwamoto and Kasagi (FIK), which allows to quantify the effect of cross-stream convection on the mean streamwise velocity, wall shear stress and bulk friction coefficient. Secondary motions are found to contribute for about $6\%$ of total friction, and to act as a self-regulating mechanism of turbulence whereby wall shear stress nonuniformities induced by corners are equalized, and universality of the wall-normal velocity profiles is established. We also carry out numerical experiments whereby the secondary motions are artificially suppressed, in which case their equalizing role is partially taken by the turbulent stresses

Thermal Comfort and Climatic Potential of Ventilative Cooling in Italian Climates

The chapter describes several climate-correlated variables and suitable key performance indicators (KPIs) to define the local ventilative cooling potential. Furthermore, a methodology is presented to verify potential correlations between climate KPIs and indoor comfort parameters. The latter values are calculated by adopting dynamic energy simulations (EnergyPlus) and comfort models – both Fanger (ISO 7730) and the recently updated EU adaptive comfort approach (EN 16798-1) – considering a sample building unit. Simulations are run by using a parametric-enabling tool developed by the research unit to check correlations and is part of work performed for the PRELUDE project, co-funded by the EU, Horizon 2020 research and innovation programme under grant agreement No 958345. The approach is applied to the whole Italian territory considering typical yearly (hourly defined) meteorological conditions for all municipalities (about 8000 data points). Strong connections between climate and building KPIs are underlined together with the high potential of ventilative cooling in reducing discomfort and energy needs in the Italian territory

Simulated Versus Monitored Building Behaviours: Sample Demo Applications of a Perfomance Gap Detection Tool in a Northern Italian Climate

Green building technologies and design-correlated choices may significantly contribute to supporting the transition toward net energy flows in the built environment. Nevertheless, large discrepancies are underlined between standard simulated and monitored building behaviours requiring approaches able to simply correlate real building behaviours and simulated ones to further support coherent certification and/or optimization. The paper focusses on the application of a semi-automatic methodology to compare and evaluate thermal behaviours of buildings considering monitored and simulated data. The approach is based on a new Python tool developed by the authors, able to manage EnergyPlus inputs and perform multi-source KPIs calculations. The mentioned tool is used here to support semi-automatic model verifications of real weather data by optimizing model parameters to fit monitored behaviours. The approach is applied in this chapter to two demo buildings, a municipality school and a residential unit, located in the Turin metropolitan area of Piedmont, in Northwest Italy

The Role of the Subcortical Dorsal Visual Pathway in the Recovery of Visual Field Defects

Lateralized post-chiasmatic lesions to the primary visual pathway result in loss of vision over the visual field retinotopically corresponding to the site of the lesion. Previous studies showed that a systematic audio-visual training could constitute an efficient tool for the rehabilitation of such disturbances as revealed by ameliorated clinical performances in various visual domains. The first part of the present dissertation aim to shed light on the substrates underlying multisensory mediated recovery of visual field defects. Experiment 1 and Experiment 2, demonstrated that a sustained audio-visual training can promote stable plastic neural changes within the cortex, likely reflecting an enhanced activity of those neural circuits connecting superior colliculus to cortical areas within the dorsal stream. The second part of the present dissertation aimed to shed light on the functionality and the characteristics of extrageniculate circuits targeting extrastriate visual areas within the dorsal stream. Experiment 3 and Experiment 4, suggested that these connections remain responsive even when a lesion prevents visual processing within the primary visual channel and that these connections could play a relevant role in the rapid processing of salient visual stimuli. Overall, the present experimental evidence suggest that visual processing depends on a variety of neural circuits and that a lesion to the primary visual pathway do not abolish the visual processing mediated by alternative routes. Moreover, activity within these routes could be exploited in a rehabilitative perspective, as revealed by ameliorated clinical performances and stable plastic neural changes induced by a systematic multisensory audio-visual training in hemianopic patients