Analysis of Vortical Structures Generated by the Swirler of Combustion Chamber

Authors: Vladislav A. Nazukin, Valery G. Avgustinovich, Vakhtang V. Tsatiashvili

Abstract:

The most important part of modern lean low NOx combustors is a premixer where swirlers are often used for intensification of mixing processes and further formation of required flow pattern in combustor liner. Swirling flow leads to formation of complex eddy structures causing flow perturbations. It is able to cause combustion instability. Therefore, at design phase, it is necessary to pay great attention to aerodynamics of premixers. Analysis based on unsteady CFD modeling of swirling flow in production combustor swirler showed presence of large number of different eddy structures that can be conditionally divided into three types relative to its location of origin and a propagation path. Further, features of each eddy type were subsequently defined. Comparison of calculated and experimental pressure fluctuations spectrums verified correctness of computations.

Keywords: DES simulation, swirler, vortical structures.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1096487

References:

[1] Lefebvre A. H. "Gas Turbine Combustion”, 3rd edition, CRC Press, New York, 2010.
[2] Gupta A. K., Lilley D. G., Syred N. "Swirling flows”, Abacus Press, Tunbridge Wells, UK, 1984.
[3] Midgley K., Spencer A., McGuirk J. J. "Unsteady flow structures in radial swirler fed fuel injectors”, ASME GT2004-53608, ASME Turbo Expo 2004, Vienna, Austria
[4] Wankhede M. J., Bresslof N. W., Keane A. J., Caracciolo L., Zedda M. "An analisys of unstable flow dynamics and flashback mechanism inside a swirl-stabilised lean burn combustor”, ASME GT2010-22253, ASME Turbo Expo 2010, Glasgow, UK.
[5] Malanosky M., Aguilar M., O’Connor J., Shin D., Noble B., Lieuwen T. "Flame leading edge and flow dynamics in a swirling, lifted flame”, ASME GT2012-68256, ASME Turbo Expo 2012, Copenhagen, Denmark
[6] Nazukin V.Avgustinovich V. et al. "Test case of 3D unsteady flows modeling using commercial and in-house codes”, Bulletin of Samara State Aerospace University, vol. 4(42), pp. 197-206, 2013.
[7] ANSYS, Inc., "ANSYS CFX-Solver theory guide”, ANSYS, Inc., Canonsburg, US, 2010.