To investigate the droplets distribution characteristics of high temperature fuel spray in high-temperature and high-velocity crossflow,an optical measurement system and an image processing method were adopted to test and analyze the droplets diameter information downstream of a cavity-strut based integrated flame-holder in heated stream.Results show that when fuel temperature is 373 K,the number of droplets in the wall cav-ity is the largest,but it is significantly reduced when the test cross sections move from the wall cavity to the cen-tre axis of test section;meanwhile,the number of droplets in different particle size ranges on each test section downstream of the flameholder is basically a normal distribution under different mainstream velocities,tempera-tures and equivalence ratios,and the diameter of most droplets are from 26 to 40 μm,followed by 21.88～25 μm and 41～55 μm,with few large droplets.When the fuel temperature increases to 473 K,the large droplets basical-ly disappear,the diameter of most droplets is 21.88～25 μm,the total number of droplets is very small,and most of the liquid fuel has evaporated.As mainstream velocity and temperature and fuel temperature increase,the total number of droplets and Sauter mean diameter(SMD)of each test section downstream of the flameholder are re-duced.Conversely,as the equivalence ratio increases,the total number of droplets and SMD of each test section increase slightly.Particularly,when the fuel temperature and the mainstream velocity increase,the decline rate of SMD is higher than that when the mainstream temperature increases.However,when the mainstream velocity exceeds 100 m/s,the number of large droplets decreases,resulting in a slower decline in SMD.In addition,SMD of the fuel spray has a small drop from 30 mm to 60 mm section,while decreases rapidly from 60 mm to 90 mm.
Integrated flameholderCrossflow jetHigh temperature fuel sprayDroplet sizeDroplet numberSauter mean diameter
NETL
NSTL
万方数据
