PIV Experiment On Double-stage Swirlers For Outlet Flow Field Study

This paper summarizes the types of aero engine combustor swirler as well as their performance characteristics and its research and development status. In addition, several flow field measurement technologies are introduced and compared with each other, including Hot Wire Analyzer (HWA), Laser Doppler Velocimetry (LDV), Phase Doppler Animometry (PDA) and Particle Image Velocimetry (PIV). According to the comparison, PIV is better than the other technologies regarding the complex and multidimensional flow field measurement at the outlet of the swirler.Two types of swirlers with different structures are designed:one has two stages of radial chamfering holes; the other has two stages of radial blades. Both swirlers are theoretically calculated, and the results show that, under the same inlet conditions, the flow coefficient and the flow resistance coefficient of the former swirler are larger than those of the latter, although their swirl numbers are equivalent. The outlet flow fields are also theoretically investigated through PIV, and the results show that, double-swirl recirculation zone appears at the outlet of the latter swirler while single-swirl recirculation zone appears at the outlet of the former swirler, and double-swirl recirculation zone is better than the single-swirl. The outlet flow fields of the two swirlers are also numerically simulated through CFD software calculation, and finds that the numerical simulation fields are similar to results of PIV measurement.Based on the study above, better understanding and some useful data of swirler outlet flow field is obtained, and experiences are gained from PIV measurement. All of these are useful for the design and test of aero engine combustor swirler.