LES Software for the Design of Low Emission Combustion Systems for Vision 21 Plants, Quarterly Report: July - September 2004

Meredith, Karl V. ; Smith, Clifford E.

CFD Research Corporation

关键词: Turbulent Flow;    Combustion;    99 General And Miscellaneous//Mathematics, Computing, And Information Science;    42 Engineering;    Computer-Aided Design;   

DOI  :  10.2172/834997
RP-ID  :  NONE
RP-ID  :  FC26-00NT40975
RP-ID  :  834997

美国|英语

来源: UNT Digital Library

【 摘 要 】

Work in this quarter focused on the continued running of two SIMVAL cases: {phi} (equivalence ratio) of (1) 0.55 and (2) 0.625. Comparisons were made between RANS and LES predictions for the {phi} of 0.625 case. The LES calculation showed a different flow pattern in the combustor compared to the RANS calculation, in particular the combustor recirculation flow pattern on the centerline is dramatically different. To demonstrate that the LES solution is accurate (and the RANS is not), non-reacting cases based on the Lilley experiment (Lilley, 1985) were run. Results from the Lilley cases verified that the LES calculations more closely match experimental velocity measurements for highly swirled, turbulent flows with a downstream constriction. In particular, RANS predictions show a strong centerline recirculation zone in the combustor, while LES predictions show positive axial velocity on the centerline, and an annular recirculation zone around the centerline. Animation files were also created this quarter, so as to better demonstrate the LES predictions.