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Parametric Study of the Effects of the Flapping Mode Excitation on the Near Field Structures of a Mach 1.3 Cold Jet

Speth, Rachelle Lea
http://rave.ohiolink.edu/etdc/view?acc_num=osu1338049511

Abstract Details

2012, Master of Science, Ohio State University, Aero/Astro Engineering.
This effort investigates numerical and physical parameters influencing an ideally-expanded Mach 1.3 jet excited by the m=+/-1 flapping mode. The excitation is imposed by eight Localized Arc Filament Plasma Actuators (LAFPA) placed around the periphery of the circular nozzle exit. The devices are modeled with a proven surface heating approach. The reference case considers the most amplified (jet column mode) frequency corresponding to a Strouhal number of 0.3, based on the diameter of the nozzle and the jet velocity, with an actuator-imposed temperature of 1500K and a duty cycle of 20%. Relative to this reference, the effects of changing frequency, duty cycle and actuator model temperature are explored. In some cases, e.g., actuator temperature, experimental data is not available, but for frequency, there is. The results are analyzed with several different quantitative and qualitative metrics, including time-averaged centerline decay and jet half width as well as phase-averaged coherent structures. Raising the frequency affects the dynamics in several ways. The number of vortical features observed in the phase-averaged data increases and the rate of decay of the centerline velocity is reduced. Furthermore, the alternating vortex ring interactions observed in the reference case are not distinct but are rather replaced by smaller structures, trends which are also observed in experiment. The flow mixes the fastest around the jet column mode (St~0.22). The higher duty cycles exhibits strengthened coherent structures and slightly higher jet growth along the flapping plane, but the overall dynamics remain the same. The response of the jet is relatively insensitive to actuator temperature model within reasonable limits. The latter two studies, with different duty cycles and actuator temperatures, are consistent with previous analyses demonstrating that instability manipulation, rather than heat deposition is the primary mechanism of control.
Datta Gaitonde, PhD (Advisor)
Mo Samimy, PhD (Committee Member)
Mei Zhuang, PhD (Committee Member)
73 p.
Aerospace Engineering; Engineering; Mechanical Engineering
supersonic jets; Large Eddy Simulation; plasma actuators

Recommended Citations

Citations

  • Speth, R. L. (2012). Parametric Study of the Effects of the Flapping Mode Excitation on the Near Field Structures of a Mach 1.3 Cold Jet [Master's thesis, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1338049511

    APA Style (7th edition)

  • Speth, Rachelle. Parametric Study of the Effects of the Flapping Mode Excitation on the Near Field Structures of a Mach 1.3 Cold Jet. 2012. Ohio State University, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1338049511.

    MLA Style (8th edition)

  • Speth, Rachelle. "Parametric Study of the Effects of the Flapping Mode Excitation on the Near Field Structures of a Mach 1.3 Cold Jet." Master's thesis, Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1338049511

    Chicago Manual of Style (17th edition)

osu1338049511
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© 2012, all rights reserved.
This open access ETD is published by The Ohio State University and OhioLINK.
Release 3.2.12