Development of a High-Energy Pulse Burst Laser System for High-Speed Fluid Dynamics and Combustion Measurements

Abstract

This paper describes recent advances made in our laboratory in the development of a new high-energy pulse burst laser system (HEPBLS) for turbulent fluid dynamics/combustion and high-speed flow measurements. We discuss new results from HEPBLS demonstrating ultra-high pulse energies greater than 2.0 Joules/pulse at 1064 nm with inter-pulse separations of 100 s (10 kHz) for burst durations exceeding 100 pulses with small levels of pulse-to-pulse fluctuations and negligible “droop” over the long pulse burst. Second harmonic generation of 532 nm with conversion efficiency greater than 50% is demonstrated for 100-pulse burst durations at repetition rates of 10 kHz and 20 kHz. The utility of the new system is shown through example 10-kHz image sequences of planar Rayleigh scattering-based mixture fraction and temperature imaging in turbulent non-reacting jets and flames, respectively.