FRACTAL CHARACTERISTICS OF AERODYNAMIC FIELD AT OUTLET OF LOW-NO_x COAXIAL SWIRLING BURNER  

作　　者：WUJiang TIANFeng-guo ZHANGMing-chuan SONGYu-bao GAOMao YINBin 

机构地区：[1]SchoolofMechanicalandPowerEngineering,ShanghaiJiaotongUniversity,Shanghai200240,China／DepartmentofPowerEngineering,ShanghaiUniversityofElectricPower,Shanghai200090China [2]SchoolofMechanicalandPowerEngineering,ShanghaiJiaotongUniversity,Shanghai200240,China

出　　处：《Journal of Hydrodynamics》2004年第1期67-73,共7页水动力学研究与进展B辑（英文版）

基　　金：theNationalNaturalScienceFoundationofChina (GrantNo :5 9876 0 19)andtheChineseSpecialFundforNationalKeyFundamentalResearch .(GrantNo :G19990 2 2 2 0 9 0 4 )

摘　　要：The primary wind of a low-NO_x coaxial swirling burner was visualized byusing glycol as smog tracer. The information of the visual flow field was input into a computerthrough image-capturing card with CCD camera as the image-capturing element. The boundary of thevisual zone, i. e. , the interface of the primary wind and secondary wind was obtained by imageprocessing. The fractal dimension (FD) of the boundary was examined and found to vary from 1. 10 to1. 40 with S_1, S_2 and ζ_1 . It is concluded that when FD is small, the complex level of theinterface is low, and mixture between the primary and secondary wind is weak near the exit of theburner at the initial phase of combustion resulting in stratified flow; when FD is big, mixturebecomes strong near the exit of the burner. It is showed that the flow with FD ranging from 1.10 to1. 20 is stratified flow, which is benefical to reduce NO_x yield and the flow with FD from 1. 25 to1. 40 is mixed flow, producing much NO_x. The mechanism of the forming of stratified flow and mixedflow was theoretically analyzed. The corresponding S_1 , S_2 and ζ_1 of these flows were given.The primary wind of a low-NO_x coaxial swirling burner was visualized byusing glycol as smog tracer. The information of the visual flow field was input into a computerthrough image-capturing card with CCD camera as the image-capturing element. The boundary of thevisual zone, i. e. , the interface of the primary wind and secondary wind was obtained by imageprocessing. The fractal dimension (FD) of the boundary was examined and found to vary from 1. 10 to1. 40 with S_1, S_2 and ζ_1 . It is concluded that when FD is small, the complex level of theinterface is low, and mixture between the primary and secondary wind is weak near the exit of theburner at the initial phase of combustion resulting in stratified flow; when FD is big, mixturebecomes strong near the exit of the burner. It is showed that the flow with FD ranging from 1.10 to1. 20 is stratified flow, which is benefical to reduce NO_x yield and the flow with FD from 1. 25 to1. 40 is mixed flow, producing much NO_x. The mechanism of the forming of stratified flow and mixedflow was theoretically analyzed. The corresponding S_1 , S_2 and ζ_1 of these flows were given.

关 键 词：low-NO_x burner aerodynamic field visual experiment image processing fractal characteristics stratified flow 

分 类 号：V211.3[航空宇航科学与技术—航空宇航推进理论与工程]