Topology transition of the multiphase reacting flow in a Lean Azimuthal Flame (LEAF) combustor

ORAL

Abstract

The pressing need to reduce the aviation carbon footprint has propelled several research endeavors to develop new combustor concepts aiming at clean combustion of sustainable aviation fuels (SAF). The current work presents the flame characteristics in a Lean Azimuthal Flame (LEAF) combustor, which has shown ultra-low NOx and soot-free liquid fuel combustion. In the presented work, three Jet-A1 sprays are injected axially into a whirling main airflow, where the interaction between them leads to a spray in a vitiated crossflow configuration. The continuous entrainment and mixing of hot products result in the sequential combustion of the sprays by each other. The combustor is investigated for the Jet-A1 thermal power range from 15 kW to 25 kW, with varying atomization-air to liquid mass flow ratio (ALR) using OH-chemiluminescence, Mie scattering, and OH-PLIF. The flame shows the LEAF configuration at high ALRs, whereas, at low ALR, the flame exhibits a tubular topology. It is shown that the convective and spray evaporation timescales are the two prominent parameters that govern the observed flame behavior. A simple model based on empirical correlation is derived, allowing us to predict the change of flame topology associated with the ALR variation in this complex LEAF configuration.

*The authors acknowledge the funding received from the Clean Sky 2 Joint Undertaking (JU) under the grant agreement No. 831804. The JU receives support from the European Union's Horizon 2020 research and innovation programme and the Clean Sky 2 JU members other than the Union. The content of this article reflects only the authors' view. The Clean Sky 2 Joint Undertaking is not responsible for any use that may be made of the information it contains.

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Presenters

  • Khushboo Pandey

    • ETH Zurich
    • CAPS Laboratory, Department of Mechanical and Process Engineering, ETH Zürich, Zürich 8092, Switzerland

Authors

  • Khushboo Pandey

    • ETH Zurich
    • CAPS Laboratory, Department of Mechanical and Process Engineering, ETH Zürich, Zürich 8092, Switzerland

  • Luigi Miniero

    • CAPS Laboratory, Department of Mechanical and Process Engineering, ETH Zurich
    • CAPS Laboratory, Department of Mechanical and Process Engineering, ETH Zürich, Zürich 8092, Switzerland

  • Ulrich Doll

    • Paul Scherrer Institut, Forschungsstrasse 111, Villigen 5232, Switzerland
    • Paul Scherrer Institute, Experimental Thermal-Hydraulics Group, Forschungstrasse 111, CH-5232 Villigen PSI, Switzerland

  • Pedro M de Oliveira

    • Hopkinson Laboratory, Department of Engineering, University of Cambridge, Cambridge CB2 1PZ, United Kingdom,

  • Epaminondas Mastorakos

    • Hopkinson Laboratory, Department of Engineering, University of Cambridge, Cambridge CB2 1PZ, United Kingdom,

  • Nicolas Noiray

    • ETH Zürich
    • ETH Zürich - CAPS Laboratory
    • CAPS Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, Z ¨ urich 8092, Switzerland
    • CAPS Laboratory, Department of Mechanical and Process Engineering, ETH Zürich, Zürich 8092, Switzerland