ID 151

Spray Characteristics of a Hybrid Airblast Pressure-Swirl Atomizer at Cold Start Conditions using Phase Doppler Anemometry

 

Abstract:

Spray Characteristics of a Hybrid Airblast Pressure-Swirl Atomizer at Cold Start Conditions using Phase Doppler Anemometry D. Shin, A.J. Bokhart, N.S. Rodrigues, P.E. Sojka, J. P. Gore, and R. P. Lucht

M. J. Zucrow Laboratories School of Aeronautic and Astronautic Purdue University West Lafayette, IN 47906 USA

In recent years, there has been an increased interest to reduce pollutant emissions from aviation gas turbine engines to mitigate climate change and improve air quality. Our study examined spray characteristics of three aviation candidate fuels as part of a larger effort by the National Jet Fuel Combustion Program (NJFCP). A hybrid airblast pressure-swirl atomizer was used to spray Jet-A (A-2), JP-5 (A-3), and a JP-5/farnesane blend (C-3) under cold start conditions: surrounding gas pressure Pa = 1 bar, fuel temperature Tf = 239 K, and atomizing gas temperature Tgas = 239 K. The pressure drop across the swirler (ΔP/P) and the fuel injection pressure differential across the pilot orifice ΔPPilot were varied. Phase Doppler Anemometry (PDA) was used to measure drop sizes and velocities at an axial location 25.4 mm downstream of the swirler exit plane for radial locations as far as 30 mm from the centerline of the spray (in 5 mm increments). D10, D32, and MMD were used as representative diameters to characterize the drop size. The mean axial drop velocity with its root-mean square was used to characterize drop velocity. Spray measurements at cold start conditions were compared with earlier measurements at near lean blowout conditions.