Numerical study of the turbulent eddies generated by the seabed roughness. Case study at a tidal power site

Stirling units are a viable option for micro-cogeneration applications, but they operate often with multiple daily startups and shutdowns due to the variability of load profiles. This work focused on the experimental and numerical study of a small-size commercial Stirling unit when subjected to cycling operations. First, experimental data about energy flows and emissions were collected during on–off operations. Second, these data were utilized to tune an in-house code for the economic optimization of cogeneration plant scheduling. Lastly, the tuned code was applied to a case study of a residential flat in Northern Italy during a typical winter day to investigate the optimal scheduling of the Stirling unit equipped with a thermal storage tank of diverse sizes. Experimentally, the Stirling unit showed an integrated electric efficiency of 8.9% (8.0%) and thermal efficiency of 91.0% (82.2%), referred to as the fuel lower and, between parenthesis, higher heating value during the on–off cycling test, while emissions showed peaks in NOx and CO up to 100 ppm but shorter than a minute. Numerically, predictions indicated that considering the on–off effects, the optimized operating strategy led to a great reduction of daily startups, with a number lower than 10 per day due to an optimal thermal storage size of 4 kWh. Ultimately, the primary energy saving was 12% and the daily operational cost was 2.9 €/day.

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Seismic Performance Assessment of Existing Steel Buildings: A Case Study

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.763.1067 ◽

2018 ◽

Vol 763 ◽

pp. 1067-1076 ◽

Cited By ~ 1

Author(s):

Luigi di Sarno ◽

Fabrizio Paolacci ◽

Anastasios G. Sextos

Keyword(s):

Numerical Study ◽

Central Italy ◽

Steel Structures ◽

Eurocode 8 ◽

Building Structures ◽

Steel Buildings ◽

Seismic Performance Assessment ◽

Masonry Infills ◽

Main Shocks

Numerous existing steel framed buildings located in earthquake prone regions world-wide were designed without seismic provisions. Slender beam-columns, as well as non-ductile beam-to-column connections have been employed for multi-storey moment-resisting frames (MRFs) built before the 80’s. Thus, widespread damage due to brittle failure has been commonly observed in the past earthquakes for steel MRFs. A recent post-earthquake survey carried out in the aftermath of the 2016-2017 Central Italy seismic swarm has pointed out that steel structures may survive the shaking caused by several main-shocks and strong aftershocks without collapsing. Inevitably, significant lateral deformations are experienced, and, in turn, non-structural components are severely damaged thus inhibiting the use of the steel building structures. The present papers illustrates the outcomes of a recent preliminary numerical study carried out for the case of a steel MRF building located in Amatrice, Central Italy, which experienced a series of ground motion excitations suffering significant damage to the masonry infills without collapsing. A refined numerical model of the sample structure has been developed on the basis of the data collected on site. Given the lack of design drawings, the structure has been re-designed in compliance with the Italian regulations imposed at the time of construction employing the allowable stress method. The earthquake performance of the case study MRF has been then investigated through advanced nonlinear dynamic analyses and its structural performance has been evaluated according to Eurocode 8-Part 3 for existing buildings. The reliability of the codified approaches has been evaluated and possible improvements emphasized.

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An energy and carbon life cycle assessment of tidal power case study: The proposed Cardiff–Weston severn barrage scheme

Energy ◽

10.1016/j.energy.2012.05.023 ◽

2012 ◽

Vol 44 (1) ◽

pp. 692-701 ◽

Cited By ~ 14

Author(s):

K.A. Kelly ◽

M.C. McManus ◽

G.P. Hammond

Keyword(s):

Life Cycle Assessment ◽

Life Cycle ◽

Tidal Power ◽

Severn Barrage

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A case study in bifurcation theory

International Journal of Modern Physics C ◽

10.1142/s0129183117501042 ◽

2017 ◽

Vol 28 (08) ◽

pp. 1750104 ◽

Cited By ~ 1

Author(s):

Youssef Khmou

Keyword(s):

Dynamical Systems ◽

Bifurcation Theory ◽

Chaotic Behavior ◽

Numerical Study ◽

Logistic Map ◽

Logistic Function ◽

Second Order ◽

Short Paper ◽

Chaotic Region

This short paper is focused on the bifurcation theory found in map functions called evolution functions that are used in dynamical systems. The most well-known example of discrete iterative function is the logistic map that puts into evidence bifurcation and chaotic behavior of the topology of the logistic function. We propose a new iterative function based on Lorentizan function and its generalized versions, based on numerical study, it is found that the bifurcation of the Lorentzian function is of second-order where it is characterized by the absence of chaotic region.

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A tidal power environmental impact assessment: case study of the Kislogubskaija experimental tidal power station (Russia)

La Houille Blanche ◽

10.1051/lhb/1997023 ◽

1997 ◽

pp. 101-105 ◽

Cited By ~ 2

Author(s):

N. N. Marfenin ◽

O. I. Malutin ◽

A. N. Pantulin ◽

N. M. Pertzova

Keyword(s):

Environmental Impact ◽

Impact Assessment ◽

Environmental Impact Assessment ◽

Power Station ◽

Tidal Power

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Numerical study of the effects of artificial island on water environment: a case study of Ocean Flower Island in Hainan, China

10.1117/12.2613739 ◽

2021 ◽

Author(s):

Zekun Song ◽

Xuefeng Xu ◽

Xingzhi Yuan ◽

Wankang Yang ◽

Liangliang Yu ◽

...

Keyword(s):

Numerical Study ◽

Water Environment

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A Numerical Study on Mitigation Strategies of Urban Heat Islands in a Tropical Megacity: A Case Study in Kaohsiung City, Taiwan

Sustainability ◽

10.3390/su12103952 ◽

2020 ◽

Vol 12 (10) ◽

pp. 3952 ◽

Cited By ~ 2

Author(s):

Jou-Man Huang ◽

Liang-Chun Chen

Keyword(s):

Thermal Environment ◽

Numerical Study ◽

Mitigation Strategies ◽

Comfort Level ◽

Tropical Region ◽

Permeable Pavement ◽

Coverage Ratio ◽

Urban Heat ◽

Cooling Effects

In recent years, with the rapid increase in global warming and urbanization, urban heat island effects (UHI) have become an important environmental issue. Taiwan is no exception, with previous studies demonstrating serious UHIs in megacities. Although existing UHI research has utilized computer simulations to analyze improvement scenarios, there are few cooling strategy studies in actual blocks of Taiwan. Therefore, this study selected a block of a megacity in a tropical region of Taiwan as a case study by ENVI-met. Five improvement strategies were tested and compared to the current situation (B0): (1) Case C1 changed to permeable pavement, (2) Case C2 increased the green coverage ratio (GCR) of the street to 60%, (3) Case C3 changed to permeable pavement and increased the GCR in the street to 60%, (4) Case C4 changed to permeable pavement, increased the GCR in the street to 60%, and increased the GCR in the parks to 80%, and (5) Case C5 changed to permeable pavement, increased GCR in the street to 60% and parks to 80%, and set the GCR on the roof of public buildings to 100%. The results showed that the average temperature of the current thermal environment is 36.0 °C, with the comfort level described as very hot. Among the five improvement schemes, C5 had the greatest effect, cooling the area by an average of 2.00 °C. Further analysis of the relationship between the different GCRs of streets (SGCR) and the cooling effects revealed that for every 10% increase in the SGCR, the temperature of the pedestrian layer was reduced by 0.15 °C.

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