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Towards Full Field Scaling of the Centerline Behavior for Initially Turbulent Axisymmetric Jets.


pdf icon Towards Full Field Scaling of the Centerline Behavior for Initially Turbulent Axisymmetric Jets. (654 K)
Papadopoulos, G.; Pitts, W. M.

FEDSM98-4892;

Summer Meeting. American Society of Mechanical Engineers (ASME)/Fluids Engineering Division. FEDSM'98. Proceedings. June 21-25, 1998, Washington, DC, 1-7 pp, 1998.

Keywords:

turbulent jets; flow measurement; turbulence; turbulent flow; velocity measurement

Abstract:

Recently the authors introduced a length scale for effectively collapsing the near field centerline velocity and mass fraction of constant and variable density axisymmetric jets whose initial conditions correspond to those of fully developed turbulent pipe flow. The new length scale incorporated the initial mass, momentum and turbulence intensity fluxes to capture the Reynolds number dependence of near field development for the velocity and scalar distributions often observed in low Reynolds number turbulent jets. The present paper makes the normalization technique more robust by extending its applicability to the intermediate and far fields using a dynamic length scale based on the local centerline turbulence intensity. The normalized velocity distributions of a constant density jet at several Reynolds numbers collapse over the entire length of jet development when the axial distance is normalized by the proposed length scale, thus achieving Reynolds number independence.