Experimental research on the cooling characteristics of an afterburner fuel injector with double-wall construction

A new afterburner fuel injector with double-wall construction was presented to meet the actual requirements. 8 test pieces of new fuel injector casings with different sizes were designed in this research. The heat transfer characteristics and cooling air flow performance were tested based on previous flow characteristics research. In view of the air extraction and cooling performance, an optimum cooling case was selected. Then, this casing of fuel injector was researched with respect to the distribution of injector temperature, change of injector temperature with cooling flow inlet total pressure and change of injector temperature with Re of cooling flow inlet. The results show that: this new afterburner fuel injector can extract enough cooling air from the fan stream (When Δp is 850 Pa, extracted air flow flux is 9 g/s) and decrease effectively the temperature of the wall of fuel injector(cooling efficiency is not less than 0.7).