<abstract xmlns="http://www.w3.org/1999/xhtml"><p> The effect of swirling air on the flow dynamics was investigated for the cold non-reacting flows and the flame arising at thermo-chemical conversion of biomass pellets downstream of a cylindrical channel. Under experimental and numerical investigation was the swirling flow dynamics with the primary axial air supply below a biomass layer and swirling air supply above it. The results indicate that for cold flows the swirling air jet outflow from tangential nozzles leads to the formation of a complex flow dynamics which is influenced both by upstream and downstream air swirl propagation near the channel walls, with correlating swirl-enhanced formation of the upstream and downstream axial flows close to the flow centreline depending on the swirling air supply rate. These axial flows can be completely balanced at their stagnation within the axial recirculation zone. It is shown that at equal boundary conditions for the swirling flame and the cold flows the swirling flow dynamics is influenced by the upstream air swirl-enhanced mixing of the reactants below the air swirl nozzles. This determines the formation of a downstream reaction zone with correlating development of the flow velocity, temperature and composition profiles in the downstream flame regions with improved combustion stability. The low swirl intensity in these regions prevents the formation of a recirculation zone</p></abstract>

The effect of swirling air on the flow dynamics was investigated for the cold non-reacting flows and the flame arising at thermo-chemical conversion of biomass pellets downstream of a cylindrical channel. Under experimental and numerical investigation was the swirling flow dynamics with the primary axial air supply below a biomass layer and swirling air supply above it. The results indicate that for cold flows the swirling air jet outflow from tangential nozzles leads to the formation of a complex flow dynamics which is influenced both by upstream and downstream air swirl propagation near the channel walls, with correlating swirl-enhanced formation of the upstream and downstream axial flows close to the flow centreline depending on the swirling air supply rate. These axial flows can be completely balanced at their stagnation within the axial recirculation zone. It is shown that at equal boundary conditions for the swirling flame and the cold flows the swirling flow dynamics is influenced by the upstream air swirl-enhanced mixing of the reactants below the air swirl nozzles. This determines the formation of a downstream reaction zone with correlating development of the flow velocity, temperature and composition profiles in the downstream flame regions with improved combustion stability. The low swirl intensity in these regions prevents the formation of a recirculation zone

Experimental and Numerical Study of Swirling Flows and Flame Dynamics

Institute of Physics, University of Latvia, 32 Miera Str., Salaspils, LV-2169, LATVIA

Latvian Journal of Physics and Technical Sciences

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

{"article-title":"Experimental and Numerical Study of Swirling Flows and Flame Dynamics"}

The effect of swirling air on the flow dynamics was investigated for the cold non-reacting flows and the flame arising at thermo-chemical conversion of biomass...

Experimental and Numerical Study of Swirling Flows and Flame Dynamics

Published Online: Sep 19, 2014

Page range: 25 - 40

DOI: https://doi.org/10.2478/lpts-2014-0021

Keywords
swirling flow dynamics, swirl intensity, recirculation zone, biomass gasification, biomass (wood) pellets, combustion

© by M. Abricka

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Experimental and Numerical Study of Swirling Flows and Flame Dynamics

Published Online: Sep 19, 2014

Page range: 25 - 40

DOI: https://doi.org/10.2478/lpts-2014-0021

Keywordsswirling flow dynamics, swirl intensity, recirculation zone, biomass gasification, biomass (wood) pellets, combustion

© by M. Abricka

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
swirling flow dynamics, swirl intensity, recirculation zone, biomass gasification, biomass (wood) pellets, combustion