국내 최대 기계 및 로봇 연구정보

기술보고서

기술보고서 게시판 내용
타이틀	Quick-Mixing Studies Under Reacting Conditions
저자	May Y. Leong and G.S. Samuelsen
Keyword	Dilution; Jet mixing flow; Gas turbines; Combustion chamber; Can; Emissions
URL	http://gltrs.grc.nasa.gov/reports/1996/CR-195375.pdf
보고서번호	NASA CR-195375
발행년도	1996
출처	NASA Glenn Research Center
ABSTRACT	The low-NOx emitting potential of rich-burn/quick-mix/lean-burn (RQL) combustion makes it an attractive option for engines of future stratospheric aircraft. Because NOx formation is exponentially dependent on temperature, the success of the RQL combustor depends on minimizing high temperature stoichiometric pocket formation in the quick-mixing section. An experiment was designed and built, and tests were performed to characterize reaction and mixing properties of jets issuing from round orifices into a hot, fuel-rich crossflow confined in a cylindrical duct. The reactor operates on propane and presents a uniform, non-swirling mixture to the mixing modules. Modules consisting of round orifice configurations of 8, 9, 10, 12, 14, and 18 holes were evaluated at a momentum-flux ratio of 57 and jet-to-mainstream mass-flow ratio of 2.5. Temperatures and concentrations of O2, CO2, CO, HC, and NOx were obtained upstream, downstream, and within the orifice plane to determine jet penetration as well as reaction processes. Jet penetration was a function of the number of orifices and affected the mixing in the reacting system. Of the six configurations tested, the 14-hole module produced jet penetration close to the module half-radius and yielded the best mixing and most complete combustion at a plane one duct diameter from the orifice leading edge. The results reveal that substantial reaction and heat release occur in the jet mixing zone when the entering effluent is hot and rich, and that the experiment as designed will serve to explore satisfactorily jet mixing behavior under realistic reacting conditions in future studies.