scholarly journals Wind Effects on a Permeable Double Skin Façade, the ENI Head Office Case Study

Fluids ◽  
2021 ◽  
Vol 6 (11) ◽  
pp. 415
Author(s):  
Giulia Pomaranzi ◽  
Ombretta Bistoni ◽  
Paolo Schito ◽  
Lorenzo Rosa ◽  
Alberto Zasso
Keyword(s):  
Energy Demand ◽  
Fluid Dynamic ◽  
Numerical Approach ◽  
Scale Model ◽  
Wind Loading ◽  
Wind Effects ◽  
Dynamic Simulations ◽  
Double Skin ◽  
The Impact

Currently, the energy and environmental efficiency of buildings has led to the development of cladding systems that may help to reduce the structure’s energy demand, using techniques such as the Permeable Double Skin Façade (PDSF). Given complex aerodynamic interactions, the presence of an external porous screen in addition to an inner skin may play a crucial role in the fluid-dynamic characterization of such buildings, making the definition of wind effects very complex. A new methodology for the quantitative assessment of the impact of wind-loading conditions on this particular type of cladding is presented. It is based on a combined experimental–numerical approach, essentially based on wind-tunnel tests on a rigid scale model and computational fluid dynamic simulations. A case study is proposed as an application of this methodology. Results include the design pressure values for the inner glazed façade and the permeable facade. An estimation of the flow rate across the porous skin is quantified using the numerical model.

The Impact of Modelling Air Compressibility in the Selection of Optimal OWC Design Parameters in Site Specific Wave Conditions

2019 ◽  
Author(s):  
Irene Simonetti ◽  
Lorenzo Cappietti
Keyword(s):  
Fluid Dynamic ◽  
Experimental Tests ◽  
Design Parameters ◽  
Dynamic Simulations ◽  
Regression Approach ◽  
Wave Conditions ◽  
A Site ◽  
The Impact ◽  
Period Wave ◽  
Selection Of

Abstract The importance of properly modelling the effects of air compressibility in the selection of the optimal design parameters for an Oscillating Water Column wave energy converter is investigated. For this purpose, a wide dataset of capture width ratios, obtained from both experimental tests and Computational Fluid Dynamic simulations, is used to formulate an empirical model able to predict the performance of the device as a function of its basic design parameters (chamber width and draught, turbine damping) and of the wave conditions (wave period, wave height). A multiple non-linear regression approach is used to determine the model numerical coefficients. The data used to formulate the model include the effects of air compressibility. The impact of considering such effects on the selection of the optimal geometry of the device is evaluated and discussed by means of the model application for the optimization of a device to be installed in a site located in the Mediterranean Sea (in front of the coast of Tuscany, Italy).

scholarly journals Joint Analysis of Cost and Energy Savings for Preliminary Design Alternative Assessment

2020 ◽  
Vol 12 (18) ◽  
pp. 7507
Author(s):  
Carlo Iapige De Gaetani ◽  
Andrea Macchi ◽  
Pasquale Perri
Keyword(s):  
Energy Demand ◽  
Alternative Assessment ◽  
Energy Savings ◽  
Life Cycles ◽  
Decision Makers ◽  
Joint Analysis ◽  
Energy Demands ◽  
Design Alternatives ◽  
The Impact

The building sector plays a central role in addressing the problem of global energy consumption. Therefore, effective design measures need to be taken to ensure efficient usage and management of new structures. The challenging task for designers is to reduce energy demands while maintaining a high-quality indoor environment and low costs of construction and operations. This study proposes a methodological framework that enables decision-makers to resolve conflicts between energy demand and life cycle costs. A case study is analyzed to validate the proposed method, adopting different solutions for walls, roofs, floors, windows, window-to-wall ratios and geographical locations. Models are created on the basis of all the possible combinations between these elements, enriched by their thermal properties and construction/management costs. After the alternative models are defined, energy analyses are carried out for an estimation of consumption. By calculating the total cost of each model as the sum of construction, energy and maintenance costs, a joint analysis is carried out for variable life cycles. The obtained results from the proposed method confirm the importance of a preliminary assessment from both energy and cost points of view, and demonstrate the impact of considering different building life cycles on the choice of design alternatives.

scholarly journals Estimation of uncertainties due to data scarcity in model upscaling: a case study of methane emissions from rice paddies in China

2014 ◽  
Vol 7 (1) ◽  
pp. 181-216 ◽  
Author(s):  
W. Zhang ◽  
T. Li ◽  
Y. Huang ◽  
Q. Zhang ◽  
J. Bian ◽  
...  
Keyword(s):  
Data Sharing ◽  
Spatial Resolution ◽  
Mainland China ◽  
Methane Emissions ◽  
Scale Model ◽  
Rice Paddies ◽  
Data Scarcity ◽  
Estimation Of Uncertainties ◽  
The Impact

Abstract. Data scarcity is a major cause of substantial uncertainties in regional estimations conducted with model upscaling. To evaluate the impact of data scarcity on model upscaling, we introduce an approach for aggregating uncertainties in model estimations. A data sharing matrix was developed to aggregate the modeled uncertainties in divisions of a subject region. In a case study, the uncertainty in methane emissions from rice paddies on mainland China was calculated with a local-scale model CH4MOD. The data scarcities in five of the most sensitive model variables were included in the analysis. The national total methane emissions were 6.44–7.32 Tg, depending on the spatial resolution used for modeling, with a 95% confidence interval of 4.5–8.7 Tg. Based on the data sharing matrix, two numeral indices, IR and Ids, were also introduced to suggest the proper spatial resolution in model upscaling.

scholarly journals Green Roofs as Effective Tools for Improving the Indoor Comfort Levels of Buildings—An Application to a Case Study in Sicily

2020 ◽  
Vol 10 (3) ◽  
pp. 893 ◽  
Author(s):  
Laura Cirrincione ◽  
Maria La Gennusa ◽  
Giorgia Peri ◽  
Gianfranco Rizzo ◽  
Gianluca Scaccianoce ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Energy Demand ◽  
Electric Energy ◽  
Simulation Models ◽  
Green Roofs ◽  
Energy Performance ◽  
Comfort Levels ◽  
Indoor Comfort ◽  
The Impact

In the line of pursuing better energy efficiency in human activities that would result in a more sustainable utilization of resources, the building sector plays a relevant role, being responsible for almost 40% of both energy consumption and the release of pollutant substances in the atmosphere. For this purpose, techniques aimed at improving the energy performances of buildings’ envelopes are of paramount importance. Among them, green roofs are becoming increasingly popular due to their capability of reducing the (electric) energy needs for (summer) climatization of buildings, hence also positively affecting the indoor comfort levels for the occupants. Clearly, reliable tools for the modelling of these envelope components are needed, requiring the availability of suitable field data. Starting with the results of a case study designed to estimate how the adoption of green roofs on a Sicilian building could positively affect its energy performance, this paper shows the impact of this technology on indoor comfort and energy consumption, as well as on the reduction of direct and indirect CO2 emissions related to the climatization of the building. Specifically, the ceiling surface temperatures of some rooms located underneath six different types of green roofs were monitored. Subsequently, the obtained data were used as input for one of the most widely used simulation models, i.e., EnergyPlus, to evaluate the indoor comfort levels and the achievable energy demand savings of the building involved. From these field analyses, green roofs were shown to contribute to the mitigation of the indoor air temperatures, thus producing an improvement of the comfort conditions, especially in summer conditions, despite some worsening during transition periods seeming to arise.

RESIDENTIAL SOLAR ENERGY POTENTIAL FOR PUBLIC DISSEMINATION: A CASE STUDY IN CONCEPCIÓN, CHILE

2016 ◽  
Vol 11 (1) ◽  
pp. 118-133 ◽  
Author(s):  
Rodrigo García Alvarado ◽  
Lorena Troncoso ◽  
Pablo Campos
Keyword(s):  
Solar Energy ◽  
Energy Demand ◽  
Geographical Location ◽  
Average Energy ◽  
Aerial Photographs ◽  
Energy Potential ◽  
Technical Standards ◽  
Dynamic Simulations ◽  
Residential Units

This paper presents a method for estimating the solar capture capacity of dwellings using the central urban area of Concepción, Chile, as a case study in order to promote self-generation of energy by residents. The method takes into account the growing domestic energy demand and the possibility of meeting this demand through integrated solar energy collection into buildings using different systems. The methodology considers a study of the potential incoming solar radiation on buildings according to their geographical location and the surrounding buildings. The capacity for solar capture is then estimated for different dwelling types according to their morphology. Subsequently, the energy contribution provided by different technologies (solar thermal, photovoltaic and hybrid) is identified in relation to the main average energy demands for electricity, water and space heating. Finally, systems for each dwelling are recommended in an urban map available online. The development is based on climate information, cartography, aerial photographs, surveys, housing models, technical standards, standardised calculations and dynamic simulations, implemented according to building layouts from an online Geographic Information System (GIS). The housing types are categorised in an urban map that relates household demands and the contribution of different solar energy systems. According to the estimates calculated, the residential units in the study offer sufficient solar capacity to supply between 40 and 60% of their energy consumption, especially in detached houses using roof-mounted hybrid systems.

Extreme fluid dynamic simulations reveal environmentally-driven morphological features of Euplectella aspergillum

2020 ◽  
Author(s):  
Giacomo Falcucci ◽  
Giorgio Amati ◽  
Pierluigi Fanelli ◽  
Vesselin Krastev ◽  
Sauro Succi
Keyword(s):  
Fluid Dynamic ◽  
Skeletal Structure ◽  
Dynamic Simulations ◽  
Hydrodynamic Stress ◽  
Environmental Physiology ◽  
Major Interest ◽  
Full Structure ◽  
Grid Points ◽  
Outstanding Question ◽  
The Impact

Abstract Due to its remarkable structural properties as well as its tantalising beauty, silica depth sponge Euplectella aspergillum has attracted the interest of scientists all over the world since its discovery [1, 2]. Its skeletal system, in fact, is composed of amorphous hydrated silica and it is arranged in a highly regular and hierarchical cylindrical lattice, endowing the whole structure with an amazing flexibility and resilience to damage, [3-7]. In contrast with the major interest in the mechanical properties of the skeletal structure of these hexatinellida, the study of the hydrodynamic fields which surround and penetrate the glassy sponge has remained largely unexplored to date, leaving an open question as to the impact of fluid dynamic patterns on Euplectella's environmental physiology. A particularly outstanding question in this respect is whether, besides boosting its tribological characteristics, the structural motifs of Euplectella may also respond to an optimisation design in terms of minimising the hydrodynamic stress experienced by the structure. This is precisely the question addressed in the present work. To this purpose, we resort to extreme fluid dynamic simulations based on the Lattice Boltzmann Method [8], featuring of the order of one hundred billion grid points and spanning four spatial decades, from the micro-scale details of the skeleton, all the way up to the full structure of Euplectella. Such in-silico experiments reproduce the actual living conditions of Euplectella [9-11], and prove that the sponge structural elements, not only reduce the overall hydrodynamic stress experienced by the skeletal structure, but also support coherent internal recirculation patterns, arguably feeding the sponge and its host organisms. The present results open the path towards a new class of numerical investigations at the intersection between fluid mechanics, computational biology and environmental physiology.

scholarly journals The total cavopulmonary connection resistance: a significant impact on single ventricle hemodynamics at rest and exercise

2008 ◽  
Vol 295 (6) ◽  
pp. H2427-H2435 ◽  
Author(s):  
Kartik S. Sundareswaran ◽  
Kerem Pekkan ◽  
Lakshmi P. Dasi ◽  
Kevin Whitehead ◽  
Shiva Sharma ◽  
...  
Keyword(s):  
Heart Rate ◽  
Single Ventricle ◽  
Fluid Dynamic ◽  
Three Dimensional ◽  
Lumped Parameter Model ◽  
Total Cavopulmonary Connection ◽  
Dynamic Simulations ◽  
Lumped Parameter ◽  
The Impact ◽  
Cavopulmonary Connection

Little is known about the impact of the total cavopulmonary connection (TCPC) on resting and exercise hemodynamics in a single ventricle (SV) circulation. The aim of this study was to elucidate this mechanism using a lumped parameter model of the SV circulation. Pulmonary vascular resistance (1.96 ± 0.80 WU) and systemic vascular resistances (18.4 ± 7.2 WU) were obtained from catheterization data on 40 patients with a TCPC. TCPC resistances (0.39 ± 0.26 WU) were established using computational fluid dynamic simulations conducted on anatomically accurate three-dimensional models reconstructed from MRI ( n = 16). These parameters were used in a lumped parameter model of the SV circulation to investigate the impact of TCPC resistance on SV hemodynamics under resting and exercise conditions. A biventricular model was used for comparison. For a biventricular circulation, the cardiac output (CO) dependence on TCPC resistance was negligible (sensitivity = −0.064 l·min−1·WU−1) but not for the SV circulation (sensitivity = −0.88 l·min−1·WU−1). The capacity to increase CO with heart rate was also severely reduced for the SV. At a simulated heart rate of 150 beats/min, the SV patient with the highest resistance (1.08 WU) had a significantly lower increase in CO (20.5%) compared with the SV patient with the lowest resistance (50%) and normal circulation (119%). This was due to the increased afterload (+35%) and decreased preload (−12%) associated with the SV circulation. In conclusion, TCPC resistance has a significant impact on resting hemodynamics and the exercise capacity of patients with a SV physiology.

Particle Image Velocimetry Measurement and Computational Fluid Dynamic Simulations of the Unsteady Flow Within a Rotating Disk Cavity

2014 ◽  
Vol 136 (11) ◽  
Author(s):  
Xiang Luo ◽  
Dongdong Liu ◽  
Hongwei Wu ◽  
Zhi Tao
Keyword(s):  
Particle Image Velocimetry ◽  
Computational Fluid Dynamic ◽  
Particle Image ◽  
Fluid Dynamic ◽  
Three Dimensional ◽  
Rotating Disk ◽  
Turbine Rotor ◽  
Dynamic Simulations ◽  
Image Velocimetry ◽  
The Impact

In this article a combined experimental and numerical investigation of the unsteady mixing flow of the ingestion gas and rim sealing air inside a rotating disk cavity was carried out. A new test rig was set up, and the experiments were conducted on a 1.5-stage turbine rotor disk and included pressure measurements. The flow structure of the mixing region of the ingestion gas and sealing air in cavity was measured using the particle image velocimetry (PIV) technique. To complement the experimental investigation and to aid in understanding the flow mechanism within the cavity, a three-dimensional (3D) unsteady computational fluid dynamic (CFD) analysis was undertaken. Both simulated and experimental results indicated that near the rotating disk, (i) a large amount of the ingestion gas will turn around and flow out the cavity due to the impact of the centrifugal force and the Coriolis force, (ii) a small amount of ingestion gas will mix transiently with the sealing air inside the cavity, whereas near the static disk, (iii) the ingestion gas will flow into the cavity along the static wall and mix with the sealing air.

scholarly journals Energy demand of occupant’s spatial modification in residential buildings. Case study of Médéa, Algeria

2018 ◽  
Vol 13 (s1) ◽  
pp. 15-28
Author(s):  
Boukarta Soufiane ◽  
Berezowska-Azzag Ewa
Keyword(s):  
Energy Demand ◽  
Residential Buildings ◽  
Negative Energy ◽  
Transformation Process ◽  
Energy Field ◽  
End Use ◽  
The Impact ◽  
Social Uses ◽  
Insulation Quality

AbstractHousing is rated as one of the most commonly consuming energy field in terms of energy end-use with 41%. Regarding the transformations dealt by dwellers for functional and social uses. The aim of this paper is: Firstly, to highlight the non-controlled transformation process made by the occupant in Algeria; Secondly, to explore the impact of the energy load of such spatial transformations. The question is approached in two tracks, (i) Through Ecotect software’s simulations (ii) and measurements through a collection of energy end-use data. Basically, the energy demand is bound to dwelling’s spatial and socioeconomic criteria. Three cases studied showed consequently 2 positive and 1 negative energy load, in which two explanations may be given: Insulation quality that occupant is lacking facilities to improve may be stated as a physical explanation, as well as for the socio economic one, the density per dwelling plays a major role, but it is the income which explains within the two approaches more than 87% of the energy end use.

scholarly journals Impact of Shape Factor on Energy Demand, CO2 Emissions and Energy Cost of Residential Buildings in Cold Oceanic Climates: Case Study of South Chile

2021 ◽  
Vol 13 (17) ◽  
pp. 9491
Author(s):  
Manuel Carpio ◽  
David Carrasco
Keyword(s):  
Co2 Emissions ◽  
Shape Factor ◽  
Energy Demand ◽  
Architectural Design ◽  
Residential Buildings ◽  
Thermal Transmittance ◽  
Energy Demands ◽  
Oceanic Climate ◽  
The Impact

The increase in energy consumption that occurs in the residential sector implies a higher consumption of natural resources and, therefore, an increase in pollution and a degradation of the ecosystem. An optimal use of materials in the thermal envelope, together with efficient measures in the passive architectural design process, translate into lower energy demands in residential buildings. The objective of this study is to analyse and compare, through simulating different models, the impact of the shape factor on energy demand and CO2 emissions depending on the type of construction solution used in the envelope in a cold oceanic climate in South Chile. Five models with different geometries were considered based on their relationship between exposed surface and volume. Additionally, three construction solutions were chosen so that their thermal transmittance gradually complied with the values required by thermal regulations according to the climatic zone considered. Other parameters were equally established for all simulations so that their comparison was objective. Ninety case studies were obtained. Research has shown that an appropriate design, considering a shape factor suitable below 0.767 for the type of cold oceanic climate, implies a decrease in energy demand, which increased when considering architectural designs in the envelope with high values of thermal resistance.

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