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Numerical Modeling in Energy and Environment

A special issue of Applied Sciences (ISSN 2076-3417). This special issue belongs to the section "Energy Science and Technology".

Deadline for manuscript submissions: closed (20 June 2022) | Viewed by 28224

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Guest Editor
Department of Civil Engineering, University of Artois, F-62400 Béthune, France
Interests: thermal-fluid sciences & engineering; advanced heat/mass transfer; porous media; geo-mechanics; fluid mechanics (turbulence, modeling, simulation); computational fluid dynamics (CFD); numerical methods for multi-scale simulations (mesoscopic and macroscopic approaches, lattice Boltzmann methods, gaskinetic schemes); thermodynamics and heat transfer

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Universidade da Coruña, A Coruna, Spain

Special Issue Information

Dear Colleagues,

Numerical methods have become too important in recent years. The evolution of computation has made it possible to create interesting tools to analyze problems. Besides, numerical models provide information not always achievable through experimental techniques.

Numerical models are applied to many fields. Between these, environment and energy constitute a constantly expanding topic.

This Special Issue seeks contributions that fit in one or more of the subjects listed below. Nevertheless, works not directly related to these shall also be considered in cases of particular interest to this Special Issue.

  • Two- and three-dimensional modeling 
  • Numerical simulations 
  • Computational fluid dynamics 
  • Finite elements analyses 
  • Mathematical models 
  • Innovative modeling approaches 
  • Challenges in numerical models 
  • Advanced models 
  • New application areas 

Dr. María Isabel Lamas Galdo
Prof. Dr. Hassane Naji
Dr. Juan de Dios Rodríguez García
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Applied Sciences is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • numerical models
  • mathematical models
  • computational models
  • energy
  • environment

Published Papers (11 papers)

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Editorial

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2 pages, 186 KiB  
Editorial
Numerical Modeling in Energy and Environment
by María Isabel Lamas Galdo
Appl. Sci. 2023, 13(1), 24; https://doi.org/10.3390/app13010024 - 20 Dec 2022
Viewed by 773
Abstract
Nowadays, numerical methods constitute an important tool in the analysis of information that cannot be obtained experimentally, or that can be obtained only at a high cost or subject to significant disadvantages [...] Full article
(This article belongs to the Special Issue Numerical Modeling in Energy and Environment)

Research

Jump to: Editorial

14 pages, 5819 KiB  
Article
Optimization of a Nature-Inspired Shape for a Vertical Axis Wind Turbine through a Numerical Model and an Artificial Neural Network
by Javier Blanco Damota, Juan de Dios Rodríguez García, Antonio Couce Casanova, Javier Telmo Miranda, Claudio Giovanni Caccia and María Isabel Lamas Galdo
Appl. Sci. 2022, 12(16), 8037; https://doi.org/10.3390/app12168037 - 11 Aug 2022
Cited by 7 | Viewed by 2091
Abstract
The present work proposes an artificial neural network (ANN) to analyze vertical axis wind turbines of the Savonius type. These turbines are appropriate for low wind velocities due to their low starting torque. Nevertheless, their efficiency is too low. In order to improve [...] Read more.
The present work proposes an artificial neural network (ANN) to analyze vertical axis wind turbines of the Savonius type. These turbines are appropriate for low wind velocities due to their low starting torque. Nevertheless, their efficiency is too low. In order to improve the efficiency, several modifications are analyzed. First of all, an innovative blade profile biologically inspired is proposed. After that, the influence of several parameters such as the aspect ratio, overlap, and twist angle was analyzed through a CFD (computational fluid dynamics) model. In order to characterize the most appropriate combination of aspect ratio, overlap, and twist angle, an artificial neural network is proposed. A data set containing 125 data points was obtained through CFD. This data set was used to develop the artificial neural network. Once established, the artificial neural network was employed to analyze 793,881 combinations of different aspect ratios, overlaps, and twist angles. It was found that the maximum power coefficient, 0.3263, corresponds to aspect ratio 7.5, overlap/chord length ratio 0.1125, and twist angle 112°. This corresponds to a 32.4% increment in comparison to the original case analyzed with aspect ratio 1, overlap 0, and twist angle 0. Full article
(This article belongs to the Special Issue Numerical Modeling in Energy and Environment)
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19 pages, 6767 KiB  
Article
Estimating the Potential Differential Settlement of a Tailings Deposit Based on Consolidation Properties Heterogeneity
by Mohammad Mahdi Badiozamani and Nicholas Beier
Appl. Sci. 2022, 12(12), 6206; https://doi.org/10.3390/app12126206 - 18 Jun 2022
Cited by 3 | Viewed by 1747
Abstract
Processing of extracted oil sands generates substantial volumes of tailings slurries. Due to the scale and inherent variability of the tailings properties, consolidation settlement is expected to occur at different rates and magnitudes across the tailings deposit. Estimating potential differential settlement of the [...] Read more.
Processing of extracted oil sands generates substantial volumes of tailings slurries. Due to the scale and inherent variability of the tailings properties, consolidation settlement is expected to occur at different rates and magnitudes across the tailings deposit. Estimating potential differential settlement of the consolidated deposit surface is an essential input for closure design. This paper presents a three-step methodology that generates multiple realizations of quasi-three-dimensional (3D) surfaces of the consolidated deposit based on the adjacent points. Each point is based on a stochastic one-dimensional (1D) large strain consolidation model developed with Monte Carlo techniques in GoldSim. The simulated surfaces provide early estimates of differential settlement based on the variability of consolidation properties expected in the tailings deposit. Comprehensive sensitivity analyses are performed for differently treated tailings material through 28 distinct scenarios to evaluate the sensitivity of the developed 1D and 3D models to consolidation input parameters over a 40-year time period. The analysis demonstrated that differential settlement is highly sensitive to tailings compressibility and hydraulic conductivity governed by the constitutive relationship parameters, and less sensitive to the solids content, specific gravity or thickness of a surcharge load. Tailings that underwent steady continuous settlement exhibited the largest degree of differential settlement. Full article
(This article belongs to the Special Issue Numerical Modeling in Energy and Environment)
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20 pages, 5797 KiB  
Article
CFD Investigations of Cyclone Separators with Different Cone Heights and Shapes
by Satyanand Pandey, Indrashis Saha, Om Prakash, Tathagata Mukherjee, Jawed Iqbal, Amit Kumar Roy, Marek Wasilewski and Lakhbir Singh Brar
Appl. Sci. 2022, 12(10), 4904; https://doi.org/10.3390/app12104904 - 12 May 2022
Cited by 14 | Viewed by 4209
Abstract
Due to the great achievements in the field of optimization of the design of cyclone separators, non-standard solutions are sought to increase their performance. Therefore, in this study, we consider the impact of different cone and cylinder height variants on the performance of [...] Read more.
Due to the great achievements in the field of optimization of the design of cyclone separators, non-standard solutions are sought to increase their performance. Therefore, in this study, we consider the impact of different cone and cylinder height variants on the performance of cyclone separators. Additionally, we propose non-standard shapes for these sections. Three different heights: H/D = 0.5, 1.0, and 1.5, with D (the main cyclone body diameter), are analyzed. Since the cone is one of the most important geometrical entities, three different shapes viz. a straight (conventional) profile, a concave profile as well as a convex profile are also taken into account. Cyclone performance is rated at three different inlet velocities viz. Uin = 10 m/s, 15 m/s, and 20 m/s. Hence, a total of 27 simulations have been performed using the Reynolds stress model. It becomes apparent from the present study that the pressure loss is lowest in the convex variant, whereas the separation efficiency is better in the conventional design. Furthermore, an increase in the length of the cylindrical section reduces pressure drop with a mild decrease in the collection efficiency in all variants. Full article
(This article belongs to the Special Issue Numerical Modeling in Energy and Environment)
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20 pages, 8126 KiB  
Article
Computational Modeling of the Thermal Behavior of a Greenhouse
by Bruno Lebre, Pedro D. Silva, Luís C. Pires and Pedro D. Gaspar
Appl. Sci. 2021, 11(24), 11816; https://doi.org/10.3390/app112411816 - 13 Dec 2021
Cited by 3 | Viewed by 2369
Abstract
The need for production of all kinds of crops in high quantities and over the entire year makes the agricultural sector one of the major energy consumers. The optimization of this consumption is essential to guarantee its sustainability. The implementation of greenhouses is [...] Read more.
The need for production of all kinds of crops in high quantities and over the entire year makes the agricultural sector one of the major energy consumers. The optimization of this consumption is essential to guarantee its sustainability. The implementation of greenhouses is a strategy that allows assurance of production needs and possesses large optimization potential for the process. This article studies different greenhouse structures by computational simulation using EnergyPlus and DesignBuilder. First, a comparison was performed between the computational results and the measured values from a greenhouse prototype at different operating conditions. Overall, the comparison shows that the computational tool can provide a reasonable prediction of the greenhouse thermal behavior, depending on the differences between the weather data modeled and observed. An outdoor air temperature difference of 16 °C can cause a difference of about 10 °C between the air temperature predicted and measured inside the greenhouse. Subsequently, a selected set of case studies was developed in order to quantify their influence on the thermal performance of the greenhouse, namely: the greenhouse configuration and orientation; the variation of indoor air renewal; changes to the characteristics of the roof; the effect of the thermal mass of the walls; and location of the greenhouse. The results show that a correct greenhouse orientation, together with a polyethylene double cover with a 13 mm air layer, a granite wall of 40 cm thickness on the north wall, and variable airflow rate, may lead to a reduction of the greenhouse energy consumption by 57%, if the greenhouse is located in Lisbon, or by 43%, if it is located in Ostersund, during the harshest months of the heating season. Full article
(This article belongs to the Special Issue Numerical Modeling in Energy and Environment)
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14 pages, 3566 KiB  
Article
Proposed Models to Improve Predicting the Operating Temperature of Different Photovoltaic Module Technologies under Various Climatic Conditions
by Dang Phuc Nguyen Nguyen, Kristiaan Neyts and Johan Lauwaert
Appl. Sci. 2021, 11(15), 7064; https://doi.org/10.3390/app11157064 - 30 Jul 2021
Cited by 10 | Viewed by 1704
Abstract
The operating temperature is an essential parameter determining the performance of a photovoltaic (PV) module. Moreover, the estimation of the temperature in the absence of measurements is very complex, especially for outdoor conditions. Fortunately, several models with and without wind speed have been [...] Read more.
The operating temperature is an essential parameter determining the performance of a photovoltaic (PV) module. Moreover, the estimation of the temperature in the absence of measurements is very complex, especially for outdoor conditions. Fortunately, several models with and without wind speed have been proposed to predict the outdoor operating temperature of a PV module. However, a problem for these models is that their accuracy decreases when the sampling interval is smaller due to the thermal inertia of the PV modules. In this paper, two models, one with wind speed and the other without wind speed, are proposed to improve the precision of estimating the operating temperature of outdoor PV modules. The innovative aspect of this study is two novel thermal models that consider the variation of solar irradiation over time and the thermal inertia of the PV module. The calculation is applied to different types of PV modules, including crystalline silicon, thin film as well as tandem technology at different locations. The models are compared to models that are described in the literature. The results obtained in different time steps show that our proposed models achieve better performance and can be applied to different PV technologies. Full article
(This article belongs to the Special Issue Numerical Modeling in Energy and Environment)
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11 pages, 6688 KiB  
Article
Proposal of a Nature-Inspired Shape for a Vertical Axis Wind Turbine and Comparison of Its Performance with a Semicircular Blade Profile
by Javier Blanco, Juan de Dios Rodriguez, Antonio Couce and Maria Isabel Lamas
Appl. Sci. 2021, 11(13), 6198; https://doi.org/10.3390/app11136198 - 4 Jul 2021
Cited by 12 | Viewed by 2820
Abstract
In order to improve the efficiency of the Savonius type vertical axis wind turbine, the present work analyzes an improvement based on an innovative rotor geometry. The rotor blades are inspired on an organic shape mathematically analyzed, the Fibonacci’s spiral, presented in many [...] Read more.
In order to improve the efficiency of the Savonius type vertical axis wind turbine, the present work analyzes an improvement based on an innovative rotor geometry. The rotor blades are inspired on an organic shape mathematically analyzed, the Fibonacci’s spiral, presented in many nature systems as well as in art. This rotor was analyzed in a wind tunnel and through a CFD model. The power coefficients at different tip speed ratios (TSR) were characterized and compared for the Savonius turbine and two versions using the Fibonacci’s spiral. One of the proposed geometries improves the performance of the Savonius type. Particularly, the optimal configuration lead to an improvement in maximum power coefficient of 14.5% in the numerical model respect to a conventional Savonius turbine and 17.6% in the experimental model. Full article
(This article belongs to the Special Issue Numerical Modeling in Energy and Environment)
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14 pages, 3025 KiB  
Article
Evaluation of the Thermal Performance and Energy Efficiency of CRAC Equipment through Mathematical Modeling Using a New Index COP WEUED
by Alexandre F. Santos, Pedro D. Gaspar and Heraldo J. L. de Souza
Appl. Sci. 2021, 11(13), 5950; https://doi.org/10.3390/app11135950 - 26 Jun 2021
Cited by 1 | Viewed by 3665
Abstract
As the world data traffic increasingly grows, the need for computer room air conditioning (CRAC)-type equipment grows proportionally. The air conditioning equipment is responsible for approximately 38% of the energy consumption of data centers. The energy efficiency of these pieces of equipment is [...] Read more.
As the world data traffic increasingly grows, the need for computer room air conditioning (CRAC)-type equipment grows proportionally. The air conditioning equipment is responsible for approximately 38% of the energy consumption of data centers. The energy efficiency of these pieces of equipment is compared according to the Energy Standard ASHRAE 90.1-2019, using the index Net Sensible Coefficient Of Performance (NetSCOP). This method benefits fixed-speed compressor equipment with a constant inlet temperature air-cooled condenser (35 °C). A new method, COP WEUED (COP–world energy usage effectiveness design), is proposed based on the IPLV (integrated part load value) methodology. The IPLV is an index focused on partial thermal loads and outdoor temperature data variation for air intake in the condenser. It is based on the average temperatures of the USA’s 29 major cities. The new method is based on the 29 largest cities worldwide and with data-center-specific indoor temperature conditions. For the same inverter compressor, efficiencies of 4.03 and 4.92 kW/kW were obtained, using ASHRAE 90.1-2019 and the proposed method, respectively. This difference of almost 20% between methods is justified because, during less than 5% of the annual hours, the inlet air temperature in the condenser is close to the NetSCOP indication. Full article
(This article belongs to the Special Issue Numerical Modeling in Energy and Environment)
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15 pages, 4170 KiB  
Article
Hydraulic Vibration and Possible Exciting Sources Analysis in a Hydropower System
by Aili Shen, Yimin Chen, Jianxu Zhou, Fei Yang, Hongliang Sun and Fulin Cai
Appl. Sci. 2021, 11(12), 5529; https://doi.org/10.3390/app11125529 - 15 Jun 2021
Cited by 10 | Viewed by 2073
Abstract
To understand the hydraulic vibration characteristics in a traditional hydropower system and identify possible exciting sources that may induce serious hydraulic vibrations in the flow passage, experimental tests and numerical calculations were conducted for different operating conditions. The experimental results show that the [...] Read more.
To understand the hydraulic vibration characteristics in a traditional hydropower system and identify possible exciting sources that may induce serious hydraulic vibrations in the flow passage, experimental tests and numerical calculations were conducted for different operating conditions. The experimental results show that the pressure fluctuations are mainly related to the vortex rope phenomena in the draft tube, and the dominant frequency of pressure fluctuation is 0.2~0.4 times the runner rotational frequency (fn). The numerical results show all the attenuating factors are negative, which indicates the system itself is stable on the condition that all the hydraulic elements have steady operating performance. The free vibration analyses confirm that the frequency range of the vortex rope in the draft tube partly overlaps the natural frequencies of the hydropower system. Apart from the vortex rope, the runner rotational frequency is another common frequency that is approximately equal to the frequency of the 10th vibration mode. From the vibration mode shapes, it is inferred that a small disturbance in its frequency close or equal to a specific natural frequency of the vibration mode could induce large pressure oscillations in the tail tunnel. In light of the system’s response to different forcing frequencies, the vortex rope formed under off-design conditions and runner rotational frequency is verified to be the potential exciting source of a traditional hydropower system, and the frequency 0.2 fn is much more dangerous than other disturbances to the system. Full article
(This article belongs to the Special Issue Numerical Modeling in Energy and Environment)
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19 pages, 5439 KiB  
Article
Advances in Simulating Radiative Transfer in Complex Environments
by Helge Simon, Tim Sinsel and Michael Bruse
Appl. Sci. 2021, 11(12), 5449; https://doi.org/10.3390/app11125449 - 11 Jun 2021
Cited by 24 | Viewed by 2668
Abstract
Accurate simulation of radiative transfer is a very important aspect in climate modeling. For microclimate models in particular, it is not only important to simulate primary but also secondary radiative fluxes in great detail, i.e., emitted longwave and reflected shortwave radiation. As there [...] Read more.
Accurate simulation of radiative transfer is a very important aspect in climate modeling. For microclimate models in particular, it is not only important to simulate primary but also secondary radiative fluxes in great detail, i.e., emitted longwave and reflected shortwave radiation. As there are always limitations regarding computational effort and memory, these radiative fluxes are commonly implemented using simplified approaches. To overcome these simplifications and, thus, increase modeling accuracy, a new radiation scheme called indexed view sphere was introduced into the microclimate model ENVI-met. This new scheme actually accounts for radiative contributions of objects that are seen by each grid cell. In order to evaluate the advantages of the new scheme, it is compared against the formerly used averaged view factor scheme. The comparison in a complex realistic urban environment demonstrated that the indexed view sphere scheme improved the accuracy and plausibility of modeling radiative fluxes. It, however, yields an increased demand of memory to store the view facets for each cell. The higher accuracy in simulating secondary radiative fluxes should, however, overturn this shortcoming for most studies, as more detailed knowledge of local microclimatic conditions in general and eventually thermal comfort can be gained. Full article
(This article belongs to the Special Issue Numerical Modeling in Energy and Environment)
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14 pages, 7779 KiB  
Article
Determination of the Vertical Load on the Carrying Structure of a Flat Wagon with the 18–100 and Y25 Bogies
by Oleksij Fomin, Alyona Lovska, Václav Píštěk and Pavel Kučera
Appl. Sci. 2021, 11(9), 4130; https://doi.org/10.3390/app11094130 - 30 Apr 2021
Cited by 4 | Viewed by 2159
Abstract
The study deals with determination of the vertical load on the carrying structure of a flat wagon on the 18–100 and Y25 bogies using mathematic modelling. The study was made for an empty wagon passing over a joint irregularity. The authors calculated the [...] Read more.
The study deals with determination of the vertical load on the carrying structure of a flat wagon on the 18–100 and Y25 bogies using mathematic modelling. The study was made for an empty wagon passing over a joint irregularity. The authors calculated the carrying structure of a flat wagon with the designed parameters and the actual features recorded during field tests. The mathematical model was solved in MathCad software. The study found that application of the Y25 bogie for a flat wagon with the designed parameters can decrease the dynamic load by 41.1% in comparison to that with the 18–100 bogie. Therefore, application of the Y25 bogie under a flat wagon with the actual parameters allows decreasing the dynamic loading by 41.4% in comparison to that with the 18–100 bogie. The study also looks at the service life of the supporting structure of a flat wagon with the Y25 bogie, which can be more than twice as long as the 18–100 bogie. The research can be of interest for specialists concerned with improvements in the dynamic characteristics and the fatigue strength of freight cars, safe rail operation, freight security, and the results of the research can be used for development of innovative wagon structures. Full article
(This article belongs to the Special Issue Numerical Modeling in Energy and Environment)
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