An experimental study of the spatial distribution of integral eddy speeds in heated, supersonic free jets is presented. The physics of such jets are of immediate interest to noise-reduction approaches for tactical aircraft jet noise. In these flows, the noise produced has a strong influence from eddy speeds, particularly for radiation in peak noise directions, due to Mach wave contributions. The measurements obtained using a time-resolved Doppler global velocimetry instrument experimentally indicate a key mechanism of the role of heating in jet noise reduction relative to the classical Lighthill U 8 scaling. Measurements are presented in jets issuing from an axisymmetric biconic nozzle at two conditions: total temperatures of 1.6 and 2.0 times that of the ambient and both at approximately 10 6 diameter Reynolds number and pressure-matched exit conditions. For the higher total temperature case, the scaled streamwise eddy convective velocities within the shear layer were measurably reduced compared to the lower total temperature case, especially as the axial distance from the nozzle exit increased. These findings confirm that core plume heating results in additional shear layer spreading and reduction of scaled eddy convective speeds, making acoustic radiation less efficient with heating. To accompany the eddy convection results, data obtained in the same facility using laser Doppler velocimetry are analyzed for second- and fourth-order moments, indicating the importance of the fourth-order correlation in the region of immediate interface between the potential core and the shear layer.


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Eddy Convection in Developing Heated Supersonic Jets


    Contributors:
    Ecker, Tobias (author) / Lowe, K. Todd (author) / Ng, Wing F. (author)

    Published in:

    AIAA Journal ; 53 , 11 ; 3305-3315


    Publication date :

    2015-09-03


    Size :

    11 pages




    Type of media :

    Article (Journal)


    Type of material :

    Electronic Resource


    Language :

    English




    Eddy Convection in Developing Heated Supersonic Jets

    Ecker, Tobias | Online Contents | 2015


    Eddy Convection in Cold and Heated Supersonic Jets

    Shea, Sean / Lowe, Kevin T. / Ng, Wing F. | AIAA | 2017


    Eddy Convection in Coaxial Supersonic Jets

    Erina Murakami / Dimitri Papamoschou | AIAA | 2000



    Supersonic submerged heated jets

    WILSON, K. / GUTMARK, E. / SCHADOW, K. et al. | AIAA | 1992