Liquid jets in subsonic airstream at elevated temperatures.

摘要

An experimental study has been performed to study the nature of breakup and penetration of liquid jets injected transversely into subsonic cross airstreams at elevated temperatures relevant to practical applications in gas turbine combustion. Two liquids (Water and Jet-A) and two injection diameters (D = 0.3 mm, 0.5 mm) have been employed in the current investigations. Liquid-to-air momentum flux ratio (q---varied from 1 to 50) and Aerodynamic Weber number (We---altered from 50 to 950) were the principal liquid jet operating conditions. The temperatures of the liquid jet and the airstream (up to 505 K) have been increased in turns to obtain a wide range of data. Pulsed shadowgraphy technique was used to study the liquid jet breakup and penetration. Two modes of breakup have been noticed: Column breakup and Surface breakup. A breakup map has been worked out to note the conditions for the commencement of surface breakup and the transition zone slope is in good agreement with the breakup maps suggested in earlier studies. A correlation has been developed to predict the jet penetration with q, D, streamwise distance (x) and temperature of the airstream (Tinfinity).