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Hammersley, R. J.

Publications and source records attributed to Hammersley, R. J..

4 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1975

Turbulent pressure field in a co-annular jet

Single point and two-point fluctuating static pressure measurements have been made in the initial mixing and transition regions in a co-annular circular jet. Space scales, correlation and time scales in the convected frame, and convection velocities have been determined for both broad band and narrow band frequency components. Analytical functionals describing the structural behavior of the turbulent pressure field have been developed from the data which are suitable for direct application in predicting the sound power level radiated from this turbulent field. Effects of both area and velocity ratios are incorporated in the model.

Hammersley, R. J.↗
NASA NTRS1973

Turbulent correlation measurements in a two-stream mixing layer.

Two point space-time measurements of the axial component of fluctuating velocity were made using linearized hot-wire anemometry. Space scales, convected frame correlations and time scales, and convection velocities in the shear layer were evaluated. Both filtered narrow and broad band convected frame autocorrelations were determined. Differences between axial broad band convection velocities and both mean turbulence and mean entrained fluid velocities were observed. Scaled broad band convection velocities for the mixing layer and simple round jets were found to collapse to a common curve. Axial narrow band convection velocities showed strong frequency and transverse position dependence.

Jones, B. G.↗
NASA NTRS1973

The turbulence structure in the plane two-stream mixing layer.

Experimental data on the turbulent structure of free shear layers is examined in incompressible air streams. Both single-point and two-point data are used to examine the large coherent structure of the mixing layer. The use of spatial scales to define this large structure is explored. Application of these scales to modeling of free shear layers to show the similarity of such flows is demonstrated. Comparison of the statistical structure with observations from shadowgraph displays of plane shear layer flows shows good qualitative and quantitative agreement.

Jones, B. G.↗