TY - JOUR
TI - Numerical simulation of the mixing and flow characteristics in lobed mixers
AU - Wang Zhi-Wu
AU - Zhang Kun
AU - Zheng Longxi
AU - Chen Xing-Gu
AU - Li Ping
AU - Nan Xiang-Yi
JN - Thermal Science
PY - 2014
VL - 18
IS - 4
SP - 1203
EP - 1212
PT - Article
AB - This paper focused on the mixer optimization by numerical simulation. The  mixing and flow characteristics inside two different lobed mixers  with/without centrum were obtained by three-dimensional CFD simulation. The  core flow was the hot rich-methane/O2（l）burnt gas, while the cold air flew  by the by-pass. The air/burnt gas flow ratio was improved from 7 to 9 in  order to confirm the effect of air/burnt gas ratio on the mixing and flow  characteristics. The simulation results indicated that no matter which mixer  was used, there were a pair of symmetrical recirculation regions in the  mixers, and the total temperature and species distribution turned to be more  uniform at the increased mixing length. The mixing performance in the lobed  mixer with centrum was slightly better than that of the lobed mixer without  centrum, and the length of recirculation region in the lobed mixer with  centrum was slightly shorter than that of the lobed mixer without centrum.  The air/burnt gas ratio had considerable effect on the mixing and flow  characteristics. The mixing performance with air/burnt gas ratio of 9 was  much better than that of air/burnt gas ratio 7. Similar mixing performance  would attain in the case of air/burnt gas ratio 9 with only half of the  mixing length in the case ofair/burnt gas ratio 7. The recirculation region  in the case of air/burnt gas ratio 9 occurred ahead of that of air/burnt gas  ratio 7, and the former was longer than the latter.