Eur. Phys. J. Plus (2021) 136: 665
https://doi.org/10.1140/epjp/s13360-021-01578-7

Regular Article

Investigation of turbulent flow structures in a wall jet can combustor: application of large eddy simulation

¹ Department of Mechanical Engineering, Faculty of Engineering and Technology, Alzahra University, Tehran, Iran
² School of Mechanical Engineering, Iran University of Science and Technology, 16846-13114, Tehran, Iran

^b bazdid@iust.ac.ir

Received: 10 February 2021
Accepted: 17 May 2021
Published online: 17 June 2021

Abstract

The present paper’s main goal is to investigate the turbulence structures and combustion characteristics in a model wall jet can combustor (WJCC) employing the large eddy simulation (LES) approach. The laminar flamelet combustion and discrete ordinates radiation models are applied in an Eulerian–Lagrangian approach to simulate a reactive spray flow. The results illustrate that LES together with an appropriate mesh and a suitable time step could properly capture the coherent vortical structures, including vortex tube, streamwise and hairpin vortices throughout the model WJCC. Also, the energy cascade from the largest turbulence length scale (integral length scale) at lower frequency of the spectrum to the smallest one along with the recirculation zones is revealed suitably. At the beginning of WJCC, immediately after the swirler, a region of dense coherent structures is formed that can influence the sharp fluctuations of the droplet. In the primary and intermediate zones the hairpin vortices and in the dilutions zone the streamwise vortices are observed more. A significant temperature reduction and a maximum scalar dissipation rate are detected in the head of hairpins. Results also indicate that the strain rate and flow temperature have an inverse relationship. The greatest strain rate is visible at the center of the collision of the primary jets and the main stream, where there is minimum temperature. The largest values of temperature are detected in the intermediate zone under the influence of the largest reverse flow.