Characteristics of closed-loop control in an axisymmetric jet at Mach 0.6

Kerwin R. Low, Ryan D. Wallace, Marlyn Y. Andino, Mark N Glauser

Research output: Contribution to conferencePaper

Abstract

A turbulent compressible Mach 0.6 jet was used as a test bed for applying closed loop flow control schemes, with the control objective of increased mixing in the shear layer observed by a change in the far-field noise. The Reynolds number, based on a nozzle exit diameter of 0.0508m, is 690,000. An azimuthal array of eight zero-net mass flux piezo-electric jets, placed at the jet exit, was used for control authority. The actuators were driven at 1900Hz, corresponding to an exit velocity ~ 50m/s from each actuator. Three control cases were tested, an open loop mode-0 excitation, a closed loop mode-0 (column mode) excitation, and a closed loop mode-1 (helical mode) excitation. A spatial Fourier azimuthal decomposition of the near-field hydrodynamic pressure at 8D in the stream wise is used for state estimation and feedback. The far-field sound was measured with six microphones oriented along a boom at increasing polar angles from 9= 15°-90° at 75D downstream to evaluate the effectiveness of each controlled case. For 9=15° (shallow angle), an overall increase in the sound at lower Strouhal numbers (0.04 - 0.2) of the jet was noticed for all controlled cases. The greatest reduction was noticed for the closed loop mode-0 case. Conversely, an overall decrease in the sound was noticed at higher jet Strouhal numbers (0.2 - 3.7). At 9 = 60° and 90°, there was an overall increase in far-field sound for all controlled cases.

Original languageEnglish (US)
Pages896-901
Number of pages6
StatePublished - Jan 1 2009
Event6th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2009 - Seoul, Korea, Republic of
Duration: Jun 22 2009Jun 24 2009

Other

Other6th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2009
CountryKorea, Republic of
CitySeoul
Period6/22/096/24/09

ASJC Scopus subject areas

  • Fluid Flow and Transfer Processes

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    Low, K. R., Wallace, R. D., Andino, M. Y., & Glauser, M. N. (2009). Characteristics of closed-loop control in an axisymmetric jet at Mach 0.6. 896-901. Paper presented at 6th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2009, Seoul, Korea, Republic of.