Cryogenic Impinging Jets Subjected to High Frequency Transverse Acoustic Forcing in a High Pressure Environment
AIR FORCE RESEARCH LAB EDWARDS AFB CA EDWARDS AFB United States
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An experimental study has been conducted to explore the coupling between the impact waves created by impinging jets and high frequency acoustic pressure perturbations. High speed, backlit imaging was used to capture the physical response of impact waves present on impingement sheet formed by two like on like impinging jets. Dynamic mode decomposition was used to extract the natural frequencies of impact waves and isolate the spatial structures response present on the impingement sheet due to the transverse acoustic forcing. Chamber pressure and jet velocity were varied until impact waves became visually prominent. After impact waves became visually prominent, the impingement sheet was subjected to incremental pressure amplitudes in a pressure anti-node PAN and pressure node PN configurations. The results indicate that impact waves appear to vanish once a certain pressure amplitude is reached. When subjected to PAN forcing the impingement sheet size grows and decays and in-plane flapping is generated under a PN forcing.
- Liquid Rocket Propellants