Analysis of the Effect of the Swirl Flow Intensity on Combustion Characteristics in Liquid Fuel Powered Confined Swirling Flames
This article examines the implementation of CFD technology in the design of the industrial liquid fuel powered swirl flame burner. The coupling between the flow field and the combustion model is based on the eddy dissipation model. The choice of the LES (Large Eddy Simulation) turbulence model over...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Isfahan University of Technology
2016-01-01
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| Series: | Journal of Applied Fluid Mechanics |
| Subjects: | |
| Online Access: | http://jafmonline.net/JournalArchive/download?file_ID=40889&issue_ID=236 |
| _version_ | 1818211001531629568 |
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| author | Marko Klancisar Tim Schloen Matjaz Hribersek Niko Samec |
| author_facet | Marko Klancisar Tim Schloen Matjaz Hribersek Niko Samec |
| author_sort | Marko Klancisar |
| collection | DOAJ |
| description | This article examines the implementation of CFD technology in the design of the industrial liquid fuel powered swirl flame burner. The coupling between the flow field and the combustion model is based on the eddy dissipation model. The choice of the LES (Large Eddy Simulation) turbulence model over standard RANS (Reynolds Averaged Navier-Stokes) offers a possibility to improve the quality of the combustion-flow field interaction. The Wall Adapting Local Eddy-Viscosity (WALE) sub-grid model was used. The reaction chemistry is a simple infinitely fast one step global irreversible reaction. The computational model was setup with the Ansys-CFX software. Through the detailed measurements of industrial size burner, it was possible to determine the natural operational state of the burner according to the type of fuel used. For the inlet conditions, axial and radial velocity components were calculated from known physical characteristics of both the fuel and air input, with the initial tangential velocity of the fuel assumed as18% of the initial axial fuel velocity. Different swirl number (S) values were studied. Addition of a surplus (in comparison to conventional flame stabilization) of tangential air velocity component (W), the rotational component increases itself with a considerably high magnitude, contributing to the overall flame stabilization. The level of S especially influences the turbulent energy, its dissipation rate and turbulent (Reynolds) stresses. In the case of high swirl number values (S > 0,65) it is possible to divide the flow field in three principle areas: mixing area (fuel-air), where exothermal reactions are taking place, central recirculation area and outer recirculation area, which primarily contains the flow of burnt flue gases. The described model was used to determine the flow and chemical behavior, whereas the liquid atomization was accounted for by LISA (Linear Instability Sheet Atomization) model incorporating also the cavitation within injection boundary condition. The boundary conditions were determined based on the data from the experimental hot water system. Depending on system requirements, especially with continuous physical processes as well as the results of experimental measurements, the paper reports on determination of the mixing field and its intensity in the turbulent flow, the description of heat release and interaction of turbulent flow field and chemical kinetics in the case of confined swirling flames. |
| first_indexed | 2024-12-12T05:25:33Z |
| format | Article |
| id | doaj.art-4b9e948532a04e06b474c93f6fea59de |
| institution | Directory Open Access Journal |
| issn | 1735-3572 |
| language | English |
| last_indexed | 2024-12-12T05:25:33Z |
| publishDate | 2016-01-01 |
| publisher | Isfahan University of Technology |
| record_format | Article |
| series | Journal of Applied Fluid Mechanics |
| spelling | doaj.art-4b9e948532a04e06b474c93f6fea59de2022-12-22T00:36:28ZengIsfahan University of TechnologyJournal of Applied Fluid Mechanics1735-35722016-01-019523592367.Analysis of the Effect of the Swirl Flow Intensity on Combustion Characteristics in Liquid Fuel Powered Confined Swirling FlamesMarko Klancisar0Tim Schloen1Matjaz Hribersek2Niko Samec3Max Weishaupt GmbHMax Weishaupt GmbHUniversity of Maribor2University of Maribor, Faculty of mechanical engineering, SloveniaThis article examines the implementation of CFD technology in the design of the industrial liquid fuel powered swirl flame burner. The coupling between the flow field and the combustion model is based on the eddy dissipation model. The choice of the LES (Large Eddy Simulation) turbulence model over standard RANS (Reynolds Averaged Navier-Stokes) offers a possibility to improve the quality of the combustion-flow field interaction. The Wall Adapting Local Eddy-Viscosity (WALE) sub-grid model was used. The reaction chemistry is a simple infinitely fast one step global irreversible reaction. The computational model was setup with the Ansys-CFX software. Through the detailed measurements of industrial size burner, it was possible to determine the natural operational state of the burner according to the type of fuel used. For the inlet conditions, axial and radial velocity components were calculated from known physical characteristics of both the fuel and air input, with the initial tangential velocity of the fuel assumed as18% of the initial axial fuel velocity. Different swirl number (S) values were studied. Addition of a surplus (in comparison to conventional flame stabilization) of tangential air velocity component (W), the rotational component increases itself with a considerably high magnitude, contributing to the overall flame stabilization. The level of S especially influences the turbulent energy, its dissipation rate and turbulent (Reynolds) stresses. In the case of high swirl number values (S > 0,65) it is possible to divide the flow field in three principle areas: mixing area (fuel-air), where exothermal reactions are taking place, central recirculation area and outer recirculation area, which primarily contains the flow of burnt flue gases. The described model was used to determine the flow and chemical behavior, whereas the liquid atomization was accounted for by LISA (Linear Instability Sheet Atomization) model incorporating also the cavitation within injection boundary condition. The boundary conditions were determined based on the data from the experimental hot water system. Depending on system requirements, especially with continuous physical processes as well as the results of experimental measurements, the paper reports on determination of the mixing field and its intensity in the turbulent flow, the description of heat release and interaction of turbulent flow field and chemical kinetics in the case of confined swirling flames.http://jafmonline.net/JournalArchive/download?file_ID=40889&issue_ID=236cfd; fluid dispersion; combustion; industrial burner; confined swirling flame; two-phase flow. |
| spellingShingle | Marko Klancisar Tim Schloen Matjaz Hribersek Niko Samec Analysis of the Effect of the Swirl Flow Intensity on Combustion Characteristics in Liquid Fuel Powered Confined Swirling Flames Journal of Applied Fluid Mechanics cfd; fluid dispersion; combustion; industrial burner; confined swirling flame; two-phase flow. |
| title | Analysis of the Effect of the Swirl Flow Intensity on Combustion Characteristics in Liquid Fuel Powered Confined Swirling Flames |
| title_full | Analysis of the Effect of the Swirl Flow Intensity on Combustion Characteristics in Liquid Fuel Powered Confined Swirling Flames |
| title_fullStr | Analysis of the Effect of the Swirl Flow Intensity on Combustion Characteristics in Liquid Fuel Powered Confined Swirling Flames |
| title_full_unstemmed | Analysis of the Effect of the Swirl Flow Intensity on Combustion Characteristics in Liquid Fuel Powered Confined Swirling Flames |
| title_short | Analysis of the Effect of the Swirl Flow Intensity on Combustion Characteristics in Liquid Fuel Powered Confined Swirling Flames |
| title_sort | analysis of the effect of the swirl flow intensity on combustion characteristics in liquid fuel powered confined swirling flames |
| topic | cfd; fluid dispersion; combustion; industrial burner; confined swirling flame; two-phase flow. |
| url | http://jafmonline.net/JournalArchive/download?file_ID=40889&issue_ID=236 |
| work_keys_str_mv | AT markoklancisar analysisoftheeffectoftheswirlflowintensityoncombustioncharacteristicsinliquidfuelpoweredconfinedswirlingflames AT timschloen analysisoftheeffectoftheswirlflowintensityoncombustioncharacteristicsinliquidfuelpoweredconfinedswirlingflames AT matjazhribersek analysisoftheeffectoftheswirlflowintensityoncombustioncharacteristicsinliquidfuelpoweredconfinedswirlingflames AT nikosamec analysisoftheeffectoftheswirlflowintensityoncombustioncharacteristicsinliquidfuelpoweredconfinedswirlingflames |