scholarly journals Simulating and Comparing Different Vertical Greenery Systems Grouped into Categories Using EnergyPlus

2021 ◽  
Vol 11 (11) ◽  
pp. 4802
Author(s):  
Alberto Arenghi ◽  
Camilla Perra ◽  
Marco Caffi

The use of vegetation for the energy efficiency of buildings is an increasingly widespread practice; therefore, the possibility of representing these systems correctly with the use of simulation software is essential. VGS performances have been widely studied, but currently, the lack of a unique simulation method to assess the efficiency of different types of VGS and the absence of studies evaluating the performances of all the systems available, proposing simulation models for each of them, leads to an incomplete energy representation. The aim of this study is to achieve a consistent and complete simulation method, comparing the different systems’ performances. The research is made up of five main steps. Firstly, a classification to group these systems into specific categories was proposed; secondly an in-depth analysis of existing literature was worked out to establish the methods used for different types of VGS. The study of plant physiology allowed the definition of an energy balance, which is valid for all vegetated surfaces; then, each category was associated to a mathematical formula and finally integrated into the EnergyPlus software. The results achieved for each model were compared evaluating two important parameters for the termohygrometric conditions control: outside walls face temperatures and operative temperatures.

2019 ◽  
Vol 140 ◽  
pp. 04005
Author(s):  
Elena Ptitsyna ◽  
Alexander Kuvaldin ◽  
Dmitry Ptitsyn

The authors have been researching the effect of polyharmonic currents (complex waveform current) on the characteristics of different types of radiators for a few years. These researches have shown an increase in the energy efficiency of installations with dark and light radiators and the ability to control the harmonic composition of radiation. It is important considering the need to harmonize the frequency characteristics of a radiator with the frequency response of an energy absorbing surface. The object of experimental research are flexible heating tape and installations with dark radiators and their joint operation modes when powered by complex waveform current from a common power source. The purpose of the work is the definition of characteristics of the flexible heating tape and dark infrared radiators when changing the amplitude and frequency of the supply voltage to develop recommendations for the selection of effective modes.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yi Huang ◽  
Chong Xu ◽  
Yufan Xiao ◽  
Bart Dewancker

AbstractThe Liyuan courtyard buildings are considered as contemporary architectural symbols of the spirit in Qingdao, China. The sustainability potentials embodied in the building is evaluated by building performance simulations analysis based on field investigation in this case study. Two models with optimization refurbishment were made through building simulation software. One model with façade supplemented in the insulation layers of the envelope walls and the other model with further upgrade with consideration of recycling materials mixed were discussed and estimated with building performance simulation method. The energy performance in the building and both scenarios designed can improve the energy efficiency, while the advanced model could achieve better result in the building energy behavior dramatically. Technologies innovation are proved to be good tools to improve energy performance the existing buildings by renovation actions such as insulation improvement and so on. It is concluded the sustainability regain its authentic appearance while achieve energy efficiency embodied within contemporary buildings through adaptational renovation strategies. Multicriteria considerations might influence the balanced between different factors when making decisions in the building restoration project, it is also expected to empower the fresh glory in the development of building protection and restoration.


1986 ◽  
Vol 18 (4-5) ◽  
pp. 15-26 ◽  
Author(s):  
D. A. Segar ◽  
E. Stamman

Most historical marine pollution monitoring has proven useless in a management context. A strategy for development of effective marine pollution monitoring programs is outlined. This strategy is based on the following steps: 1) systematic evaluation of the management information needs, 2) identification of the hypothetical impacts associated with those management concerns, and 3) investigation of the feasibility of monitoring those effects such that the existence, or absence, of a specified level of effects can be established in a statistically-valid manner. There are two fundamentally different types of monitoring program: site-specific and regional. These two types of program differ markedly in scope and approach when designed through application of this strategy. The strategy requires development of null hypotheses which address management concerns and which are amenable to scientific testing. In order for the program to be successful, the null hypotheses selected for inclusion in a marine pollution monitoring program must address levels of effect which are predefined to be environmentally significant. The definition of environmentally significant effect levels is a difficult process which must be primarily the responsibility of the managerial community.


Author(s):  
Lucas Konnigk ◽  
Benjamin Torner ◽  
Martin Bruschewski ◽  
Sven Grundmann ◽  
Frank-Hendrik Wurm

Abstract Purpose Cardiovascular engineering includes flows with fluid-dynamical stresses as a parameter of interest. Mechanical stresses are high-risk factors for blood damage and can be assessed by computational fluid dynamics. By now, it is not described how to calculate an adequate scalar stress out of turbulent flow regimes when the whole share of turbulence is not resolved by the simulation method and how this impacts the stress calculation. Methods We conducted direct numerical simulations (DNS) of test cases (a turbulent channel flow and the FDA nozzle) in order to access all scales of flow movement. After validation of both DNS with literature und experimental data using magnetic resonance imaging, the mechanical stress is calculated as a baseline. Afterwards, same flows are calculated using state-of-the-art turbulence models. The stresses are computed for every result using our definition of an equivalent scalar stress, which includes the influence from respective turbulence model, by using the parameter dissipation. Afterwards, the results are compared with the baseline data. Results The results show a good agreement regarding the computed stress. Even when no turbulence is resolved by the simulation method, the results agree well with DNS data. When the influence of non-resolved motion is neglected in the stress calculation, it is underpredicted in all cases. Conclusion With the used scalar stress formulation, it is possible to include information about the turbulence of the flow into the mechanical stress calculation even when the used simulation method does not resolve any turbulence.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Hazem M. El-Hageen ◽  
P.G. Kuppusamy ◽  
Aadel M. Alatwi ◽  
M. Sivaram ◽  
Z. Ahamed Yasar ◽  
...  

AbstractDifferent types of laser source modulation techniques have been used in various applications depending on the objective. As optical systems extract the laws and the best solutions from experiments and simulations, the present study uses simulation software with different modulation types so the output signals can be compared. The modulators used are Mach-Zehnder, which is an external modulator, and electro-absorption modulator and laser rate equation modulator, which are direct modulators. All these types have an optical link multimode (MM) fiber with a photodiode in the receiver end that can be modeled. The input and output signals are analyzed using different types of modulations.


Author(s):  
Cristina Portalés ◽  
Manolo Pérez ◽  
Pablo Casanova-Salas ◽  
Jesús Gimeno

Abstract3D modelling of man-made objects is widely used in the cultural heritage sector, among others. It is relevant for its documentation, dissemination and preservation. Related to historical fabrics, weaves and weaving techniques are still mostly represented in forms of 2D graphics and textual descriptions. However, complex geometries are difficult to represent in such forms, hindering the way this legacy is transmitted to new generations. In this paper, we present the design and implementation of SILKNOW’s Virtual Loom, an interactive tool aimed to document, preserve and represent in interactive 3D forms historical weaves and weaving techniques of silk fabrics, dating from the 15th to the 19th centuries. To that end, our tool only requires an image of a historical fabric. Departing from this image, the tool automatically subtracts the design, and allows the user to apply different weaves and weaving techniques. In its current version, the tool embeds five traditional weaving techniques, 39 weaves and six types of yarns, which have been defined thanks to close collaboration of experts in computer graphics, art history and historical fabrics. Additionally, users can change the color of yarns and produce different 3D representations for a given fabric, which are interactive in real time. In this paper, we bring the details of the design and implementation of this tool, focusing on the input data, the strategy to process images, the 3D modelling of yarns, the definition of weaves and weaving techniques and the graphical user interface. In the results section, we show some examples of image analysis in order to subtract the design of historical fabrics, and then we provide 3D representations for all the considered weaving techniques, combining different types of yarns.


Energies ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 224
Author(s):  
Lucia Cattani ◽  
Anna Magrini ◽  
Paolo Cattani

Water extraction from air, based on reverse cycle systems, is becoming a technology more and more diffused and various models of air to water generators (AWG) are now available, all claiming the best efficiency. To date, there is not a standard indicator stating energy efficiency for AWGs, neither in the literature nor in technical practice. The only evaluation parameter, that can be found is a sort of specific energy consumption (SEC) without any clear indications about the involved calculation terms, definition of hypotheses, or environmental conditions. The current work is a first proposal of an indicator to standardise the AWG efficiency evaluation. The indicator is called WET (Water Energy Transformation); it states water production as a useful effect of an AWG machine and calculates its energy performance with an approach similar to COP (Coefficient of Performance) and EER (Energy Efficiency Ratio) evaluation. The indicator is meant to be a normalised tool that permits comparing different AWG machines, but it is also the first part of a wider study, currently under development that is oriented to obtain a global index formulation that combines WET itself, EER and COP, and it is intended for a comprehensive evaluation of all the useful effects of a reverse cycle in integrated machines, in compliance with the current efficiency evaluation approach. The current paper presents the WET equation, with a discussion about involved terms, a set of normalised calculation conditions and some application examples, including a comparison with SEC.


Insects ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 169
Author(s):  
Federico Lessio ◽  
Alberto Alma

This paper reviews the existing predictive models concerning insects and mites harmful to grapevine. A brief conceptual description is given on the definition of a model and about different types of models: deterministic vs. stochastics, continuous vs. discrete, analytical vs. computer-based, and descriptive vs. data-driven. The main biological aspects of grapevine pests covered by different types of models are phenology, population growth and dynamics, species distribution, and invasion risk. A particular emphasis is put on forecasting epidemics of plant disease agents transmitted by insects with sucking-piercing mouthparts. The most investigated species or groups are the glassy-winged sharpshooter Homalodisca vitripennis (Germar) and other vectors of Xylella fastidiosa subsp. fastidiosa, a bacterium agent of Pierce’s disease; the European grape berry moth, Lobesia botrana (Denis and Schiffermuller); and the leafhopper Scaphoideus titanus Ball, the main vector of phytoplasmas agents of Flavescence dorée. Finally, the present and future of decision-support systems (DSS) in viticulture is discussed.


2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Xiaoqin Hao ◽  
Jia Yu ◽  
Weidong He ◽  
Yi Jiang

To solve the problem of the effective cushioning of fast-moving mechanical components in small ring-shaped spaces, the factors affecting the compression and energy absorption properties of small-sized hollow metal tubes were studied. Simulation models were constructed to analyse the influences of tube diameter, wall thickness, relative position, and number of stacked components on the compression and energy absorption properties. The correctness of the simulation method and its output were verified by experiments, which proved the effectiveness of compression and energy absorption properties of small-sized thin-walled metal tubes. The research provides support for the application of metal tube buffers in armament launch technology and engineering practice.


1999 ◽  
Vol 121 (3) ◽  
pp. 441-448 ◽  
Author(s):  
I. Lee-Prudhoe ◽  
R. S. Sayles ◽  
A. Kaderic

Experimental results are presented along the lines of the early work of Moore (1948) where a hard smooth roller is pressed into a softer rough surface to study the resulting real to apparent areas of contact and their associated local contact pressures. Results are presented for a hard steel roller deforming mild-steel and aluminum-alloy rough surface specimens. An analysis of the local contact mechanics is performed before and after indentation using a recently developed numerical elastic contact simulation method which allows local asperity contact pressures and areas to be studied in detail. The method is shown to reveal the level and distribution of pressures and asperity contact areas prevalent during the indentation process, and therefore allows the contribution of elastic and plastic load support to be quantified. The persistence of asperities during such indentation tests is discussed in terms of the pressures the asperities can support in relation to reported mechanisms of persistence. Results of subsequent sub-surface stresses are also presented and discussed in terms of how the method might be used to create an elastic-plasticdeformation model that can account for asperity persistence in future numerical contact simulation models.


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