Pressure Measurements in a Supersonic Jet with Fluid Inserts
Open Access
- Author:
- Falcone, James Michael
- Area of Honors:
- Aerospace Engineering
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Philip John Morris, Thesis Supervisor
Dennis K Mclaughlin, Thesis Honors Advisor - Keywords:
- Aerospace
Fluid Inserts
Fluid Corrugations - Abstract:
- Extremely high levels of noise, capable of damaging the human ear, are emitted from the exhaust leaving military grade aircraft engines. Military personnel, specifically those on the decks of aircraft carriers, are regularly exposed to this dangerous noise and as a result often sustain permanent hearing damage. A novel approach to reducing the noise levels experienced by these personnel is through the use of fluid inserts in the diverging section of an aircraft engine’s nozzle. These fluid inserts blow additional air into the exhaust flow which has been shown to effectively reduce noise. This study sought to further the understanding of the flow physics by which the fluid inserts can reduce noise. Pressure surveys of a scaled GE 404 class engine nozzle were completed with and without the use of fluid inserts. The alterations created by the fluid inserts in the downstream flow are visualized and discussed. The experimental results are also compared to RANS CFD simulations of jets from the same nozzle and operating conditions to further evaluate the computations and improve future simulations. Throughout the duration of the experiments, jet asymmetries were also carefully explored for the baseline jet as well as the fluid insert jet. Asymmetries within a jet can have an impact on noise reduction by unknowingly redistributing the flow in undesirable ways. The reasons for these asymmetries are proposed.