scholarly journals REVIEW OF CFD SIMULATION OF OXY-COAL COMBUSTION FOR ELETRICAL POWER GENERATION: OPPORTUNITIES AND CHALLENGES

2016 ◽  
Vol 15 (2) ◽  
pp. 76
Author(s):  
F. S. Nascimento ◽  
M. A. R. Nascimento ◽  
C. J. R. Coronado ◽  
L. O. Rodrigues ◽  
J. A. Carvalho Jr ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Coal Combustion ◽  
Cfd Simulation ◽  
Numerical Models ◽  
Cost Savings ◽  
Pollutant Emissions ◽  
Computational Time ◽  
Simulation Techniques ◽  
Reduction Of Co2 ◽  
Physical Phenomena

The oxy-combustion has generated significant interested for reduction of CO2 emission when the fossil fuel is coal, due to simplification on the separation process of CO2 from the flue gas, it can be more easily stored in reservoir. The CFD numerical simulation techniques in oxy-coal combustion has the potential to contribute to designers in cost savings and reduced computational time; Furthermore, such techniques also provide a robust tool for better understanding and description of the aerothermodynamics processes involved, as well as, aiding the design of most efficient furnaces. However, to obtain representative results of the physical phenomena, the numerical models employed by CFD needs to be suitable for oxy-coal combustion. So, the aim of the paper is to carry out a review of the recent models that are being used for turbulence, combustion and pollutant emissions. Moreover, it is shown a comparison of different results obtained in the numerical simulation of oxy-coal combustion among new models, existing models and experiments. The analysis of the models and experiments shows that the challenges that are still being faced to obtain better accuracy of numerical simulation results. Improvements in the models for oxy-coal combustion can be seen like potential opportunities to investigate and optimize the process that occur in the combustion.

scholarly journals Design improvement of an airbox for a passenger vehicle

2021 ◽  
Vol 2120 (1) ◽  
pp. 012010
Author(s):  
J Tan ◽  
N Z Abu Bakar
Keyword(s):  
Numerical Simulation ◽  
Pressure Drop ◽  
Simulation Model ◽  
Cfd Simulation ◽  
Pollutant Emissions ◽  
Passenger Vehicle ◽  
Repeated Testing ◽  
Road Transportation ◽  
Ansys Fluent ◽  
Testing Cost

Abstract The purpose of an airbox is to provide the engine with a clean air flow for combustion. The high velocity of the fluid flow across the airbox will create a pressure drop resulting a decline in the vehicle’s performance. This project collaborates with an Original Equipment Manufacturer (OEM) to develop a numerical simulation model for a new airbox design and to compare its pressure drop with OEM production design. Reducing the pressure drop across the airbox can increase the efficiency of a vehicle, hence, reducing CO2 emissions. This research focuses on the passenger type vehicle as it is the highest source of carbon dioxide (CO2) being emitted for road transportation and these pollutant emissions have also caused many health problems on human. ANSYS Fluent program was used to carry out Computational Fluid Dynamics (CFD) simulation for both OEM and the new design. Then, the same simulation setup was used for the new design. The inlet size of the new design is larger when compared to the OEM design. After analysing both models, it was determined that the main reason behind the pressure loss was caused by the shape of the airbox and turbulent flow inside. The new airbox design shows reduction of 96% in the pressure drop within it and in return, enhancing the performance of the passenger vehicle. This conclude that numerical simulation model is able to provide a good indicator for the designer to choose the best design and proceed with fabrication and conduct actual test, thus saving a lot of prototyping and repeated testing cost.

Structural Non-Linear Models and Simulation Techniques

2016 ◽  
pp. 540-584
Author(s):  
Jorge M. Delgado ◽  
Antonio Abel R. Henriques ◽  
Raimundo M. Delgado
Keyword(s):  
Computational Models ◽  
Linear Models ◽  
Civil Engineering ◽  
Numerical Models ◽  
Probabilistic Approach ◽  
Latin Hypercube Sampling ◽  
Computational Time ◽  
Rc Structures ◽  
Simulation Techniques ◽  
Non Linear

Advances in computer technology allow nowadays the use of powerful computational models to describe the non-linear structural behavior of reinforced concrete (RC) structures. However their utilization for structural analysis and design is not so easy to be combined with the partial safety factors criteria presented in civil engineering international codes. Trying to minimize this type of difficulties, it is proposed a method for safety verification of RC structures based on a probabilistic approach. This method consists in the application of non-linear structural numerical models and simulation methods. In order to reduce computational time consuming the Latin Hypercube sampling method was adopted, providing a constrained sampling scheme instead of general random sampling like Monte Carlo method. The proposed methodology permits to calculate the probability of failure of RC structures, to evaluate the accuracy of any design criteria and, in particular, the accuracy of simplified structural design rules, like those proposed in civil engineering codes.

scholarly journals Potential uses of Numerical Simulation for the Modelling of Civil Conflict

2017 ◽  
Vol 23 (1) ◽  
Author(s):  
Lucy Burton ◽  
Shane D. Johnson ◽  
Alex Braithwaite
Keyword(s):  
Numerical Simulation ◽  
New York ◽  
Civil Wars ◽  
Numerical Models ◽  
Civil Conflict ◽  
Relative Power ◽  
Asymmetric Warfare ◽  
Simulation Techniques ◽  
Stochastic Events ◽  
Conflict Outcomes

AbstractThis paper explores ways in which civil conflict can be simulated using numerical methods. A general two-party model of conflict is developed by extending an approach proposed by [Christia, F., (2012), Alliance Formation in Civil Wars, Cambridge University Press, New York], which is based on a metric of the ‘relative power’ that exists between the state and a rebel group. Various definitions of relative power are considered and one of these is chosen to illustrate different types of two-sided armed conflict, namely direct-fire, guerrilla and asymmetric warfare. The additional suggestion of Christia that random or stochastic events can lead to unexpected conflict outcomes is also further extended in this paper. The inclusion in the model of terms describing concurrent rebel recruitment of civilians and state deployment of troops are then described. Examples are presented for various hypothetical cases. It is demonstrated that numerical simulation techniques have great potential for modelling civil war. The Christia approach is shown to provide an excellent basis from which numerical models of civil conflict can be built and from which the progress of a conflict can usefully be visualised graphically.

Modeling Under Hood Cooling Using a Coupled-Code Approach

2003 ◽  
Author(s):  
Gino Bella ◽  
Rossella Rotondi
Keyword(s):  
Computational Models ◽  
Optimal Solution ◽  
Computational Design ◽  
Industrial Applications ◽  
Computational Time ◽  
Simulation Techniques ◽  
Flow And Heat Transfer ◽  
Complex Simulation ◽  
Coupled Codes ◽  
Physical Phenomena

The need to shorten the development time for new engine and vehicles is leading to the increasing use of computational design and simulation methods in the automotive industry. In the last years 3D computational models have been used successfully in vehicle and engine development. It is clear that in this kind of simulation, the input complexity, the output data management and the computational time increase. On the other hand 3D simulations increase the details of the results and their link with the analyzed geometry. During a vehicle design several numerical techniques can be used (finite difference, finite volume, spectral methods, boundary elements, etc.) Often, in a complex simulation, that involves several different physical phenomena such as fluid flow and heat transfer only the use of different simulation techniques allows to obtain good results in a acceptable time. In several industrial applications the use of coupled codes, with different features (1D, 3D or different numerical schemes) could provide an optimal solution for the simulation approach. In this paper an example of a complex simulation of an Under Hood Cooling (UHC) of a vehicle is carried out using two different 3D codes with different numerical approaches with the objective to reduce the simulation time [1].

scholarly journals Selection of Parameters for Blade-to-blade Finite-volume Mesh for CFD Simulation of Axial Turbines

2018 ◽  
Vol 220 ◽  
pp. 03003 ◽  
Author(s):  
Grigorii Popov ◽  
Valery Matveev ◽  
Oleg Baturin ◽  
Yulia Novikova ◽  
Andrey Volkov
Keyword(s):  
Numerical Simulation ◽  
Finite Volume ◽  
Cfd Simulation ◽  
Numerical Models ◽  
Turbulence Models ◽  
Model Parameters ◽  
Working Process ◽  
Axial Turbines ◽  
Volume Mesh ◽  
Selection Of

This paper describes the first part of the global work done by the authors aimed at finding the best settings for a numerical model for the calculations of axial uncooled turbines using RANS approach. The authors studied more than 80 papers published over the past 5 years in the examined field. Their analysis did not allow to identify unified recommendations for the creation of numerical models. The selection of model parameters is usually motivated by general considerations of numerical simulation, which follow from the method. In none of the papers the selection of parameters is correlated with the structure of the flow in the turbine. Many specific simulation issues were not covered at all. For the research, more than 1000 models of full-size axial turbines (including multistage turbines) and their elements were created. They differed in the number, size, parameters of the elements of finite volume meshes, in turbulence models, in the degree of simplification. The results were compared with the experimental data. As a result, the following was obtained: 1. A method for developing and optimizing the working process of turbines using numerical simulation based on the RANS approach is proposed. The search for the optimal turbine configuration is carried out using light computational models, which are based on the simplified channel geometry and the finite volume mesh. Their application makes it possible to reliably find the optimal turbine configuration 2.8 times faster. The characteristics of the selected variants are verified with the help of verification models that consider the real geometry of the channels and have a minimum error. 2. Recommendations are given on the selection of parameters for finite volume meshes and the selection of turbulence models for numerical models of the working process of axial turbines designed to perform optimization and verification calculations.

scholarly journals Integration of Geographic Information System frameworks into domain discretisation and meshing processes for geophysical models

2014 ◽  
Vol 7 (5) ◽  
pp. 5993-6060 ◽  
Author(s):  
A. S. Candy ◽  
A. Avdis ◽  
J. Hill ◽  
G. J. Gorman ◽  
M. D. Piggott
Keyword(s):  
Numerical Simulation ◽  
Numerical Models ◽  
Simulation Models ◽  
Geographic Information ◽  
Data Provenance ◽  
New Approach ◽  
Gis Tools ◽  
Terrain Following ◽  
Physical Interfaces ◽  
Physical Phenomena

Abstract. Computational simulations of physical phenomena rely on an accurate discretisation of the model domain. Numerical models have increased in sophistication to a level where it is possible to support terrain-following boundaries that conform accurately to real physical interfaces, and resolve a multiscale of spatial resolutions. Whilst simulation codes are maturing in this area, pre-processing tools have not developed significantly enough to competently initialise these problems in a rigorous, efficient and recomputable manner. In the relatively disjoint field of Geographic Information Systems (GIS) however, techniques and tools for mapping and analysis of geographical data have matured significantly. If data provenance and recomputability are to be achieved, the manipulation and agglomeration of data in the pre-processing of numerical simulation initialisation data for geophysical models should be integrated into GIS. A new approach to the discretisation of geophysical domains is presented, and introduced with a verified implementation. This brings together the technologies of geospatial analysis, meshing and numerical simulation models. This platform enables us to combine and build up features, quickly drafting and updating mesh descriptions with the rigour that established GIS tools provide. This, combined with the systematic workflow, supports a strong provenance for model initialisation and encourages the convergence of standards.

scholarly journals Structural Non-Linear Models and Simulation Techniques

2016 ◽  
pp. 369-406
Author(s):  
Jorge M. Delgado ◽  
Antonio Abel R. Henriques ◽  
Raimundo M. Delgado
Keyword(s):  
Computational Models ◽  
Linear Models ◽  
Civil Engineering ◽  
Numerical Models ◽  
Probabilistic Approach ◽  
Latin Hypercube Sampling ◽  
Computational Time ◽  
Rc Structures ◽  
Simulation Techniques ◽  
Non Linear

Advances in computer technology allow nowadays the use of powerful computational models to describe the non-linear structural behavior of reinforced concrete (RC) structures. However their utilization for structural analysis and design is not so easy to be combined with the partial safety factors criteria presented in civil engineering international codes. Trying to minimize this type of difficulties, it is proposed a method for safety verification of RC structures based on a probabilistic approach. This method consists in the application of non-linear structural numerical models and simulation methods. In order to reduce computational time consuming the Latin Hypercube sampling method was adopted, providing a constrained sampling scheme instead of general random sampling like Monte Carlo method. The proposed methodology permits to calculate the probability of failure of RC structures, to evaluate the accuracy of any design criteria and, in particular, the accuracy of simplified structural design rules, like those proposed in civil engineering codes.

Simulation and Modeling of Turbulent Flows

1996 ◽  
Keyword(s):  
Numerical Simulation ◽  
Turbulent Flow ◽  
Turbulent Flows ◽  
Simulation And Modeling ◽  
Simulation Techniques ◽  
Rational Development ◽  
Group Methods ◽  
Turbulent Closure ◽  
The Subject ◽  
Renormalization Group Methods

This book provides students and researchers in fluid engineering with an up-to-date overview of turbulent flow research in the areas of simulation and modeling. A key element of the book is the systematic, rational development of turbulence closure models and related aspects of modern turbulent flow theory and prediction. Starting with a review of the spectral dynamics of homogenous and inhomogeneous turbulent flows, succeeding chapters deal with numerical simulation techniques, renormalization group methods and turbulent closure modeling. Each chapter is authored by recognized leaders in their respective fields, and each provides a thorough and cohesive treatment of the subject.

scholarly journals Industry 4.0 Maturity Model Assessing Environmental Attributes of Manufacturing Company

2021 ◽  
Vol 11 (11) ◽  
pp. 5151
Author(s):  
Michal Zoubek ◽  
Peter Poor ◽  
Tomas Broum ◽  
Josef Basl ◽  
Michal Simon
Keyword(s):  
Industry 4.0 ◽  
Industrial Revolution ◽  
Cost Savings ◽  
Pollutant Emissions ◽  
Value Stream Mapping ◽  
Maturity Model ◽  
Value Stream ◽  
Environmental Attributes ◽  
Lean And Green ◽  
Environmentally Responsible Manufacturing

The primary purpose of this article is to present a maturity model dealing with environmental manufacturing processes in a company. According to some authors, Industry 4.0 is based on characteristics that have already been the focus of “lean and green” concepts. The goal of the article was to move from resource consumption, pollutant emissions, and more extensive manufacturing towards environmentally responsible manufacturing (ERM). Using environmental materials and methods reduces energy consumption, which generates cost savings and higher profits. Here, value stream mapping (VSM) was applied to identify core processes with environmental potential. This paper provides an understanding of the role of environmental manufacturing in the era of the Fourth Industrial Revolution.

scholarly journals Model-Based Control of Torque and Nitrogen Oxide Emissions in a Euro VI 3.0 L Diesel Engine through Rapid Prototyping

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1107
Author(s):  
Stefano d’Ambrosio ◽  
Roberto Finesso ◽  
Gilles Hardy ◽  
Andrea Manelli ◽  
Alessandro Mancarella ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Rapid Prototyping ◽  
Nitrogen Oxide ◽  
Thermal State ◽  
Pollutant Emissions ◽  
Computational Time ◽  
Nox Emissions ◽  
Model Based ◽  
Brake Mean Effective Pressure ◽  
The Impact

In the present paper, a model-based controller of engine torque and engine-out Nitrogen oxide (NOx) emissions, which was previously developed and tested by means of offline simulations, has been validated on a FPT F1C 3.0 L diesel engine by means of rapid prototyping. With reference to the previous version, a new NOx model has been implemented to improve robustness in terms of NOx prediction. The experimental tests have confirmed the basic functionality of the controller in transient conditions, over different load ramps at fixed engine speeds, over which the average RMSE (Root Mean Square Error) values for the control of NOx emissions were of the order of 55–90 ppm, while the average RMSE values for the control of brake mean effective pressure (BMEP) were of the order of 0.25–0.39 bar. However, the test results also highlighted the need for further improvements, especially concerning the effect of the engine thermal state on the NOx emissions in transient operation. Moreover, several aspects, such as the check of the computational time, the impact of the controller on other pollutant emissions, or on the long-term engine operations, will have to be evaluated in future studies in view of the controller implementation on the engine control unit.

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