On the highly swirling flow through a confined bluff-body

Alisson Vinicius Brito Lopes, Nwabueze Emekwuru, Bernard Bonello, Ebrahim Abtahizadeh

    Research output: Contribution to journalArticlepeer-review

    4 Citations (Scopus)
    4 Downloads (Pure)

    Abstract

    We address highly swirling, confined-bluff-body-flow evolving through a burner; particularly, contributions of the swirling motion to a central-recirculation-zone (CRZ) downstream the injector. Previous studies suggest that flame stability reduces in combustors lacking this zone; careful consideration of the CRZ is thus desirable. We use Reynolds-Averaged-Navier–Stokes (RANS) and Large-Eddy-Simulation (LES) to simulate the flow, and the influence of the swirl device was included in defining the inflow conditions for LES simulations. We use mean velocity profiles and turbulence statistics to test results. There is qualitative agreement between computed and reported experimental data, and we document quantitative differences obtained with the RANS models. LES velocity field results are mostly within 3% of the experimental data, better than the latest reported LES data, reinforcing the suitability of our approach. We took advantage of the quality of the LES mesh, which solves 95.6% of the resolved-turbulence-energy, to present the vorticity structures showing the precessing vortex motion on the CRZ boundaries. Anisotropic states of the Reynolds-stress were characterized with the aid of an anisotropy invariant map, a novelty for this type of burner; the turbulence states considerably vary inside the burner, behaving isotropically in the center of the CRZ, whereas axisymmetric turbulence is predominant in the other areas of the CRZ. The results reinforce the importance of applying appropriate turbulence models and inflow conditions for simulations involving confined-bluff-body-flows in order to capture the main flow fields and structures in the CRZ.
    Original languageEnglish
    Article number055105
    Number of pages25
    JournalPhysics of Fluids
    Volume32
    Issue number5
    Early online date11 May 2020
    DOIs
    Publication statusPublished - 11 May 2020

    Bibliographical note

    This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Brito Lopes, AV, Emekwuru, N, Bonello, B & Abtahizadeh, E 2020, 'On the highly swirling flow through a confined bluff-body', Physics of Fluids, vol. 32, no. 5, 055105 and may be found at https://aip.scitation.org/doi/10.1063/1.5141531

    Funder

    UGC-UKIERI (Grant No. 2016-17-050).

    Keywords

    • Swirl flow
    • LES

    ASJC Scopus subject areas

    • Modelling and Simulation
    • Aerospace Engineering
    • Mechanical Engineering
    • Energy Engineering and Power Technology

    Fingerprint

    Dive into the research topics of 'On the highly swirling flow through a confined bluff-body'. Together they form a unique fingerprint.

    Cite this