Session: 04-23: Combustion Dynamics - Numerical Methods I

Paper Number: 81552

81552 - Numerical Study of Flow Characteristics of a Central-Staged Swirl Combustor 

The two-combustion-zone design approach was adopted in order to achieve good idle LBO in a central-staged swirl combustor. The main-stage configuration, which had both swirling air and non-swirling air, was designed for the purpose of reducing the quenching effect of main-stage air on pilot flame. However, the effect of the non-swirling air had not been studied systematically. In the present study, the effect of non-swirling air proportion as well as non-swirling air passage location on flow field are investigated through the large eddy simulation (LES). The numerical method is first validated by comparing the numerical results of time-average velocity profiles at different axial locations with PIV results. The grid scale is analyzed through M criterion to guarantee that most turbulent kinetic energy can be resolved by the present mesh. Proper orthogonal decomposition (POD) is used to extract the coherent structures from the turbulence flow in order to clarify the interaction between main-stage flow as well as pilot-stage flow. Multiple monitor points are set up in swirling flow and shear layers. The fast Fourier transform (FFT) is used to transform the time-domain signal, which collected by monitor points, into the frequency-domain. By using phase-averaged method, the vortical structures corresponding to the normalized frequency of the flow are captured. Dynamic behavior of combustor with different main-stage configurations are further investigated.

Presenting Author: Xiangzhou Feng Northwestern Polytechnical University

Presenting Author Biography: Presenting author: Xiangzhou Feng, once studied at the School of Power and Energy, Northwestern Polytechnical University and got a BA and then an MA. The author is currently working on the Ph.D degree at Northwestern Polytechnical University. The author’s research mainly focuses on the combustion performance of central-staged combustor, combustion instability, etc.

Authors:

Xiangzhou Feng Northwestern Polytechnical University
Jianqin Suo Northwestern Polytechnical University
Pengfei Zhu Northwestern Polytechnical University
Yue Li Northwestern Polytechnical University
Qiandong Li Northwestern Polytechnical University