An experimental investigation of the pressure-velocity cross-correlation in an axisymmetric jet

André M. Hall, Mark N. Glauser, Charles E. Tinney

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

This study investigates the strength of the pressure-velocity correlations of a Mach 0.6, axisymmetric jet, with an exit nozzle diameter of 50.8mm. Experiments are conducted at a constant exit temperature of 25°C, and exit pressure and temperature are balanced with ambient conditions. The instantaneous velocity measurements are acquired using a multi-component LDA system who 's measurement volume is traversed along several radial and streamwise locations within the potential core, and mixing layer regions of the flow. The fluctuating lip pressure is simultaneously sampled by an azimuthal array of (15) dynamic transducers, evenly spaced at 24°. These are positioned just outside the shear layer near the jet exit at z/D=0,875, and 1.75R from the centerline, where the pressure field has been shown to be hydrodynamic. From this multi-point evaluation, the cross-correlations between the near-field pressure array (fixed), and streamwise component of the velocity field (traversed) are examined as a function of radial, streamwise, and also azimuthal separation. The results illustrate a remarkable coherence between the near field pressure and the velocity field, on the order of 25%. Streamwise convection velocities of 0.77U j and 0.77U j are calculated within the potential core and shear layer, respectively. Analysis of the coherency spectra illustrates the frequency band of the correlations and suggest that the potential core and mixing layer regions of the flow are, in general, governed by the high and low frequency motions of the flow, respectively. The azimuthal modal distribution of the cross-correlation shows the dominance of the column mode of the jet, with no higher modes exhibited within the potential core region, and only modes 1 & 2 within the shear layer.

Original languageEnglish (US)
Title of host publicationProceedings of ASME Fluids Engineering Division Summer Conference, 2005 Symposia, FEDSM2005
Pages357-368
Number of pages12
StatePublished - Dec 19 2005
Event2005 ASME Fluids Engineering Division Summer Conference - Houston, TX, United States
Duration: Jun 19 2005Jun 23 2005

Publication series

NameProceedings of the American Society of Mechanical Engineers Fluids Engineering Division Summer Conference
Volume1 PART A

Other

Other2005 ASME Fluids Engineering Division Summer Conference
CountryUnited States
CityHouston, TX
Period6/19/056/23/05

ASJC Scopus subject areas

  • Engineering(all)

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  • Cite this

    Hall, A. M., Glauser, M. N., & Tinney, C. E. (2005). An experimental investigation of the pressure-velocity cross-correlation in an axisymmetric jet. In Proceedings of ASME Fluids Engineering Division Summer Conference, 2005 Symposia, FEDSM2005 (pp. 357-368). [FEDSM2005-77338] (Proceedings of the American Society of Mechanical Engineers Fluids Engineering Division Summer Conference; Vol. 1 PART A).