Searched for: collection%253Air
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document
Danczul, Tobias (author), Hetebrij, Wouter (author), Khalighi, Faeze (author), Kogler, Lukas (author), Lahaye, D.J.P. (author), Luckins, Ellen (author), Munters, Wim (author), Neunteufel, Michael (author), Vuik, Cornelis (author)
conference paper 2022
document
Lahaye, D.J.P. (author), Nakate, P.A. (author), Vuik, Cornelis (author), Juretic, F. (author), Talice, Marco (author)
The operation of large industrial furnaces will continue to rely on hydrocarbon fuels in the near foreseeable future. Mathematical modeling and numerical simulation is expected to deliver key insights to implement measures to further reduce pollutant emissions. These measures include the design optimization of the burners, the dilution of...
journal article 2022
document
Nakate, P.A. (author), Lahaye, D.J.P. (author), Vuik, Cornelis (author)
Thermal nitric-oxide (NOx) formation in industrial furnaces due to local overheating is a  widely known problem. Various industries made significant investments to reduce thermal NOx by varying the operating conditions and designs of the furnace. Finding optimal operating conditions or design parameters by experimenting in...
report 2021
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El Abbassi, M. (author), Lahaye, D.J.P. (author), Vuik, Cornelis (author)
One of the quickest ways to influence both the wall temperature and thermal NOx emissions in rotary kilns is to change the air–fuel ratio (AFR). The normalized counterpart of the AFR, the equivalence ratio, is usually associated with premixed flames and studies of its influence on diffusion flames are inconsistent, depending on the application....
journal article 2021
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Lahaye, D.J.P. (author), El Abbassi, M. (author), Vuik, Cornelis (author), Talice, Marco (author), Juretic, F. (author)
This work studies how non-premixed turbulent combustion in a rotary kiln depends on the<br/>geometry of the secondary air inlet channel. We target a kiln in which temperatures can reach values above 1800 degrees Kelvin. Monitoring and possible mitigation of the thermal nitric-oxide (NOx) formation is of utmost importance. The performed reactive...
journal article 2021
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Nakate, P.A. (author), Lahaye, D.J.P. (author), Vuik, Cornelis (author)
Thermal nitric-oxide (NOx) formation in industrial furnaces due to local overheating is a widely known problem. Various industries made significant investments to reduce thermal NOx by varying the operating conditions and designs of the furnace. It is difficult to find the optimal operating conditions that minimize NOx formation in the...
journal article 2021
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El Abbassi, M. (author), Lahaye, D.J.P. (author), Vuik, Cornelis (author)
This paper verifies a mathematical model that is developed for the open source CFD-toolbox OpenFOAM, which couples turbulent combustion with conjugate heat transfer. This feature already exists in well-known commercial codes. It permits the prediction of the flame’s characteristics, its emissions, and the consequent heat transfer between...
conference paper 2021
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Nakate, P.A. (author), Lahaye, D.J.P. (author), Vuik, Cornelis (author), Talice, Marco (author)
The emissions from the industrial furnaces impact the environment. Among the various factories, those having anode baking furnaces are working on reducing the pollutant emissions. The aerodynamics in the furnace influences the emissions due to the high dependence of combustion and radiation phenomena on the mixing characteristics. Therefore,...
journal article 2020
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Lahaye, D.J.P. (author), Vuik, Cornelis (author)
The load flow equations express the balance of power in an electrical power system. The power generated must equal the power consumed. In the AC time-harmonic case, the load flow equations are non-linear in the voltage phasors associated with the nodes in the network. The development of future power systems urgently requires new, highly...
book chapter 2019
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El Abbassi, M. (author), Dimas Ramadhan Abdillah Fikri, Dimas (author), Lahaye, D.J.P. (author), Vuik, Cornelis (author)
The wish to reduce the environmental footprint and to enhance economic gains of rotary kilns pushes the numerical simulation of combustion to include conjugate heat transfer. In this paper we study the influence of the refractory wall and radiative heat loss to the ambient, on the combustion process of a reference kiln model. Numerical results...
conference paper 2018
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Nakate, P.A. (author), Lahaye, D.J.P. (author), Vuik, Cornelis (author), Talice, Marco (author)
The anode baking process is developed and improved since the 1980s due to its importance in Aluminium industry. The process is characterized by multiple physical phenomena including turbulent flow, combustion process, conjugate heat transfer, and radiation. In order to obtain an efficient process with regards to quality of anodes, soot-free...
conference paper 2018
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Lahaye, D.J.P. (author), Vuik, C. (author)
Networks for the high-voltage distribution of electrical energy are currently undergoing farreaching developments. National power grids are evolving fromstatic entities, producingmainly a uni-directional flow from generation to loads, to more dynamic and decentralized structures. These emerging power systems should accommodate the local...
journal article 2015
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Thomas, R. (author), Lahaye, D.J.P. (author), Vuik, C. (author), Van der Sluis, L. (author)
Simulation of current interruption is currently performed with non-ideal switching devices for large power systems. Nevertheless, for small networks, non-ideal switching devices can be substituted by arc models. However, this substitution has a negative impact on the computation time. At the same time, these simulations are useful to design...
conference paper 2015
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Thomas, R. (author), Lahaye, D.J.P. (author), Vuik, C. (author), Van der Sluis, L. (author)
report 2013
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Idema, R. (author), Papaefthymiou, G. (author), Lahaye, D.J.P. (author), Vuik, C. (author), Van der Sluis, L. (author)
Current and future developments in the power system industry demand fast power flow solvers for larger power flow problems. The established methods are no longer viable for such problems, as they are not scalable in the problem size. In this paper, the use of Newton-Krylov power flow methods is proposed, and a multitude of preconditioning...
report 2012
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Idema, R. (author), Lahaye, D.J.P. (author), Vuik, C. (author)
The inexact Newton method is widely used to solve systems of non-linear equations. It is well-known that forcing terms should be chosen relatively large at the start of the process, and be made smaller during the iteration process. This paper explores the mechanics behind this behavior theoretically using a simplified problem, and presents...
report 2011
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Sheikh, A.H. (author), Lahaye, D. (author), Vuik, C. (author)
A Helmholtz solver whose convergence is parameter independent can be obtained by combining the shifted Laplace preconditioner with multigrid deflation. To proof this claim, we develop a Fourier analysis of a two-level variant of the algorithm proposed in [1]. In this algorithm those eigenvalues that prevent the shifted Laplace preconditioner...
report 2011
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Idema, R. (author), Lahaye, D.J.P. (author), Vuik, C. (author), Van der Sluis, L. (author)
The power flow problem is generally solved by the Newton-Raphson method with a sparse direct solver for the linear system of equations in each iteration. While this works fine for small power flow problems, we will show that for very large problems the direct solver is very slow and we present alternatives that scale much better in the problem...
report 2010
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Sheikh, A.H. (author), Vuik, C. (author), Lahaye, D. (author)
report 2009
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Idema, R. (author), Lahaye, D.J.P. (author), Vuik, C. (author)
report 2009
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