EXPERIMENTAL AND COMPUTATIONAL ANALYSIS OF n-DECANE SPRAY CHARACTERISTICS DISCHARGED FROM A PRESSURE-SWIRL NOZZLE INTO AEROENGINE-LIKE CONDITIONS

The spray characteristics of a pressure-swirl nozzle have an important impact on the performance of an aeroengine. In this work, the spray experiment of a pressure-swirl nozzle was conducted in a constant volume chamber to mimic the combustion chamber environment of a real aeroengine. n-Decane, chosen as a surrogate of aviation fuel, was injected into different environmental conditions to analyze its spray characteristics. A coupling numerical method, using the Euler continuum model for the flow inside the nozzle and the Lagrange discrete phase model for the external spray, was implemented to simulate the fuel injection process under the same environmental conditions as the experiment. The results show that the interface of the gas-liquid two-phase flow becomes larger with the increase of environmental pressure Penv, while the gradients of axial velocity Vz and tangential velocity Vθ decrease. The spray cone angle decreases rapidly and remains nearly unchanged with the increase of Penv. This coupling numerical method underestimated the specific value of the spray cone angle but can closely predict the trend of spray cone angle with the increase of Penv. Generally, this work is valuable for the design of fuel injection systems of aeroengines.