Generic Centerline Velocity Decay Curve for Initially Turbulent Axisymmetric Jets

Published

March 1, 1999

Author(s)

G Papadopoulos, William M. Pitts

Abstract

Recently the authors introduced a length scale which effectively collapsed the near field centerline development of velocity and mass fraction for 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 per unit area to capture the Reynolds number dependence of near field development for the velocity and scalar distributions observed in low Reynolds number turbulent jets. The present paper extends the analysis for a constant density jet to the intermediate and self-similar far fields further downstream using a dynamic length scale based on the local centerline turbulence intensity. The normalized mean velocity distributions of an air jet collapse over the entire flaw distance investigated when the axial distance is normalized by the proposed length scale, thus scaling the virtual origin shtft and effectively incorporating the Reynolds number dependence.

Citation

Journal of Fluids Engineering-Transactions of the ASME

Volume

121

Pub Type

Journals

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Keywords

turbulent jets, velocity measurement, flow measurement, jets, turbulence, turbulent flow

Citation

Papadopoulos, G. and Pitts, W. (1999), Generic Centerline Velocity Decay Curve for Initially Turbulent Axisymmetric Jets, Journal of Fluids Engineering-Transactions of the ASME, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=911644 (Accessed December 5, 2024)